Well, I’d not expected to be at this stage of things for another 6 months, at least. But ‘reality just is’ – E.M.Smith. So here I am.
The earlier articles in this series are here:
https://chiefio.wordpress.com/2017/03/14/cord-cutting-step-2-roku/
https://chiefio.wordpress.com/2015/06/08/cord-cutting-not-new/
I’m posting this article from my bedroom, on a nice 32 inch HDTV that was sold for “dirt cheap” as it seems 720p is yesterdays dogfood and 1080p is on clearance. I’d bought a 720p Toshiba for something like $128? at Best Buy. The intent was to have something to replace a dead SD TV while I learned enough about HDTV to make an informed decision.
I made the mistake of setting it up in the living room on the coffee table so the spouse could see what I was “up to” and assist in the decision making about what was to be done in the living room (as that very large SD Sony was getting buzz in the sound when text was displayed). Well, SWMBO “helped” alright. “It was decided” that ‘my’ set was to remain in the living room until something better replaced it…
The Shopping, Phase 2
So I went on an accelerated learning curve. Yesterday I bought a ‘clearance’ model 43 inch LG 1080p for the living room. I’m now partly through the setting up process (as of last night).
Why LG? The spouse and I did a round robin of The Usual Stores and took a look at screens. LG and Sony were the best picture by far (with Samsung a very close 3rd) and everything else was “also ran” or some brand from China we had never heard of before. (The Best Buy house band of “Insignia” looked good, but who knows what it is or if the FBI was invited in; while COSTCO had a TCL that looked nice and they do strong evaluations, but again who knows what it is). In the “reputational search”, a lot of folks complained about the new Sony sets having weak plastic shells and that the “smart” functions failed a lot. Don’t know if it was sour grapes by competitors, or folks “like me” who had a Perfect Sony that was built like a tank and lasted 20? years – God knows – complaining that this wasn’t quite the same. In any case, the complaints on LG were fewer. Then, it was being sold much cheaper. (Likely due to the push into 4K land and the lack of traditional audio out jacks – at least 50% of the complaints on the smaller LG sets were about inability to connect their sound bar or legacy high end sound systems AFTER they got it home and discovered the lack of “goezoutas”.
How much less? A couple of $Hundred.
To me, that’s enough to be ‘real money’.
OK, cutting to the chase, the 40 inch LG was sold out ( $280 or so price point, so not a surprise) and I took about a $Hundred upsell to the next larger size that came with “smart” built in. But nobody could tell me what that meant other than that I could get Netflix and it involved apps. One cute and, it turns out, smarter than the rest, clerk told me (on direct questioning of what that meant – Roku or Chromecast or…) that it was “their own version and app store”. And that it is. The offerings have all the dreck of ROKU filtered out, and several of the better higher end things in, plus some Korean favorites (guess where LG is from…).
LG Stuff
Setting it up was easy. The feet and plastics seem nice and sturdy. The color and overall screen performance is fine and off axis is great compared to others. Sound is quite good (note: I’m not a soundbar person, I’ve got high end cut-off from hearing loss, and hate “thumpa thumpa” over the top base…) and I’m generally pleased.
The Bad:
Their app store is very limited compared to ROKU. Partly that is just the filtering out the crap; but I have not found a lot of very good, and free, stations. Like RT, Al Jazeera, and more. Were I limited to the LG Apps, especially after drowning in the flood of all things ROKU, I’d be disappointed. It is ‘enough’ to get started (what with things like Netflix, Vudu, etc.) but a lot of it requires sending money.
The set keeps trying to toss me into a ‘scan for local stations’ when I accidentally do anything on the remote that puts it in ‘TV Mode’. I’ll need to fish out the bowtie antenna at least long enough to let it scan and find something so it stops that.
Plugging in the Roku Stick, there were a LOT of issues. Picture would freeze. Sometimes a channel would drop. Seems the set has 2 HDMI ports, and one is “IN only” while the other is “In and Out”. The “In and Out” one confuses the ROKU. Works fine in the other one. As that, now, fills my “IN only” HDMI ports, I suspect I will end up in ‘swap the plugs’ land if I want to add a computer, like the one I’m using now…
Don’t expect to plug in legacy sound gear. No headphone jack. No bluetooth to a headset. No RCA jacks. There is a square optical digital sound out, so you can go spend a ton of money on something new. Enjoy… /sarc; Or find something new that takes HDMI for sound and doesn’t mind being flooded with video out stream on the same HDMI.
It seems (after way too little time exploring) like their interface puts the “apps” in order of addition across the bottom of one screen (home screen) in a single row. So maybe only having a few is a good thing… You get to scroll and scroll and scroll…
The So-So:
They do give you their legal agreements on the screen during set up. It basically says they will spy on you and use it to sell you stuff. They collect your identity information and your IP address and share it around with only a few close trusted friends, or anyone they merge with in the future, or any ‘partner’ where it might be helpful … to them. OK, it IS what I expected, nice to see it in print.
So far it has NOT demanded any PII (like credit cards or email addresses) but I’ve only chosen free content so far.
The set comes with zero documentation beyond how to attach the feet and the usual safety nags (one in about 3 dozen languages…) I didn’t need any to set it up, but get to “go fish” on their internet site to find how to use advanced functions (like the 4 colored buttons across the bottom of the remote, one of which says something about ‘eye mode’ when pushed and who knows what the others do).
The Chrombox and the Toshiba
So the experience with the Roku and the 2-way HDMI told me I need to learn a lot more about what that flavor of HDMI is, and does, and is compatible with, before I stick a second thing into the LG set.
The good news is that I get “my” TV back…
The bad news is that putting the Chromebox OR a Pi on the LG TV is ‘off in the future’ after some learning curve on HDMI variations and compatibility. IFF it had had 3 HDMI ports, I’d be posting this from the living room couch…
Instead, I’ve got the Toshiba set up back in the bedroom, and the Chromebox plugged into it. (Note to self: Get a bluetooth or wireless keyboard with trackpad – Sitting 3 feet from a 3 foot monitor screen your eyes are too slow in the scan from one side to the other… ;-)
OK, it clearly is working AS a Chromebox. That means all my marked Youtubes et. al. and my “Internet TV links” from the tab up top ( https://chiefio.wordpress.com/tv/ ) are all now available on a large screen with better sound than the old PC; AND it means I can use my bluetooth headset with the Chromebox.
At this point, I think I’m about 50% done.
This Morning and The Future
So this morning, before even getting out of bed, using the ROKU (that I’d moved in here for the morning), I was able to do a quick “toe dip” tour of the daily news on France-24, Sky News, RT, Al Jazeera, Newsmax, and NBC. I also did a ‘dip’ into the WSJ online video feed, but didn’t get to the Washington Post app yet.
I do have to give a shout out to NBC. They had a ‘please give us feedback’ form on their page saying it was Beta. They had a live news now feed that I started out watching. Then I did a tour of their on demand videos. They have a LOT of stuff up. Having the live feed (2 of them!) was nice as a “just get me hooked up with what is happening now”. I’d suggest adding a 3rd live feed that’s a 30 minute repeating cycle of whatever news is hot at the moment. Repeat the big 3 or 5 stories of the day, and a constantly changing set of minor stories that pop up, then fade as not that important. Their Beta is better than many folks “production”.
Then I made morning tea and set up the Chromebox.
It is VERY clear to me that pretty much all the Internet TV services exist to harvest information about you and use it to sell you stuff, or to sell information to others. Just FYI. So I figured that given Chrome is already doing that too, I might as well hook it up and play with it.
FWIW, I’m now a bit more motivated to try Kodi on the Pi. Likely sometime a few weeks from now. Sound to the Viewsonic didn’t work, likely as I was using HDMI for the video through an HDMI to DVI converter, and round plug for audio, and everyone expects Real HDMI to a Real HDTV. At least, that’s what I hope. So “some Pi” will be tested driving the TV.
I really really hope I can get a Pi running with some kind of software that lets ME control my information. While I’m not particularly bothered that someone will find out I like watching “Plan 9 From Outer Space” or watch a LOT of news, or that we watch NCIS, I don’t need them inspecting the list of things I’ve put on the “take a look at it once” list and start putting up ads for Russian Brides because that fits some demographic of folks watching the Russian Travelogues or ‘whatever’.
So that’s what’s on the cards “going forward”:
Test the Pi. Maybe build a Kodi driving the TV.
Learn the kinds of HDMI and who plays well with what so something in addition to ROKU can be plugged into the LG.
Clean up all the packing material et. al. from the living room ;-)
SLOWLY sort through the 344 remaining ROKU apps and toss some more trash (like the 2 dozen Sci-Fi and Horror ones where I’m sure I don’t need them all)
Learn the LG store better. Figure out if the “smart” function is really worth anything to me, or if I’m just going to buy a second ROKU. BTW, found out the two more expensive ROKU devices are for 4K feeds. At this point, I see no reason to “go there” as I don’t have a 6 foot tall TV ;-) IFF I deprecate the built in “smart” function, I’ll block it from tattling via the expedient of pointing the WiFi interface to ‘dead air’. On the “someday” list is to just build a filter that identifies and blocks the tattling function in my interior router. Just enough to prevent the tattle but not so much as to break services ;-)
Figure out if I can get / use “Chromecast” via the Chromebox and direct HDMI feed of the TV. That would let me explore what Google thinks I ought to be watching on TV ;-) At that point, I’d have 3 different HDTV “smart TV” options to inspect. LG, Roku, and Chromecast. That would just leave AppleTV as one of interest (being $100+ not of all that much interest…) and Amazon Fire. (From the commercial set… I’m sure their might be others, but I’ve not noticed them yet. I’m more interested in the Roll-Your-Own world of the rebellion ;-) But this set would let me do some interesting observation / evaluation.
OK, with that, I’m off to try catching up on all the things I was supposed to be doing before my priorities were “made right” by SWIMBO… /snarc; Which includes catching up on some Global Warming and Political websites and returning yet again to my queue of “postings in progress” and moving a few further along.
Musings from the Chiefio 
I have been buying TCL for about 5 years now (yes, years). For the fundraiser raffle. The picture looks fine, and the life is about the same as the higher end. So much so that on Amazon, they are no longer the “loss leaders” and instead have moved into the mainstream of their offerings.
If it makes a difference, one year, my BIL asked if I would mind if he kept the TCL and raffled off the TV they had from another vendor (same specs basically). So they are definitely not the bottom of the barrel.
@Phil:
That they made it through the COSTCO filters says a lot ( COSTCO has a brutal selection process part of which is for quality…).
I just professed ignorance, and chose not to do the research to learn about them Frankly, by the time I looked at them at COSTCO, the spouse had already expressed a strong interest in either a Sony or LG … so what was the point in doing the background on it?… Sigh…
You will likely find some advanced HDMI configuration options buried in the LG menus. You should then be able to Disable Audio Return Channel (ARC – useful if you are watching through an LG app and the TV is connected through an Audio-Video Receiver (AVR)); also Consumer Electronics Control (CEC – allows HDMI-connected devices to control each others’ power, volume, channel…). That would give you two old-fashioned HDMI connections.
Not too expensive to convert TOSLink optical audio to digital. https://www.amazon.com/Digital-Optical-Analog-audio-converter/dp/B004C4WPXA for example, plus an inexpensive TOSLink cable. This might please people with better hearing since your overall approach to technology suggests you have very good sound reproduction equipment that predates drop in hearing acuity / career sigma ratio.
@Nick:
Yeah, I was just cruising Amazon looking at various converter and mux / mixer options. That it is cheap, frankly, just makes it worse . The whole TV industry has gone on a binge of removing connectors and it is stupid. THE one thing you can guarantee is that there will be a need for “goezintas” and “goezoutas”. So instread of including sonething that would cost $5 at the factory, they guarantee a significant number of customers will be sent to Amazon for $20 of stuff plus shipping. And / or spend hours searching arcane technical points. Just stupid.
Yeah, I’ve got some stereo gear, but post hearing loss. Better gear helps hearing. In fact, a good sound bourd with many frequency bands boosted or flattened and a range compressor is what makes a really good hearing aid. Removing spurious “case noise” from vibrating plastics also helps, especialy when it is in a band you hear well and the desired signal is not, so simple audio boost makes things worse…
But even just the typical set of game console for the kids, video recorder, DVD player and sound bar exceeds their connectors.
So now I’ve got the Roku in, the satellite decoder connected, and both the video recorder and DVD player looking for a place to plug in with nowhere to go and nothing connecting my stereo to an audio feed. Plus a Pi or Chromebox to connect “someday”. The only unused connectors being the optical audio out (so buy some adapter after some unknown amount of more research) and the ARC HDMI (so short by a couple AND I get to do more study).
Unfortunately there wasn’t much of a choice. Everything I looked at was too short of connectors and lacked support for the BILLIONS of systems already in homes world wide. I guess they figure everone will go buy all new stereo, video, and games gear… NOT!
Yes, this bothers me. So much so I considered just buying used gear from when they did have enough.
In any case, thanks for the pointer to a gizmo. For now I get to teach the spouse what cables to plug and unplug when she wants to swap from recorder to DVD to satellite….
Somehow your selection process and “country of origin” got me to, erm, thinking, albeit musically.
We’ve been looking at smart and no-so-smart phones, and with all that’s going on with big-brother,
it appears that Sam Sung somewhat out of tune (sorry…). Then, erm, some tunes popped up
Korea,
I’ve just bought a set from Korea
And suddenly the sound
Is not the same surround
I’ve known.
Korea,
I thought that I never would see ya’
The Smart TV’s of old
Were often undersold:
Not YOU…..
Ko-rea,
Tune it loud, and there’s music playing
Tune it soft, and you’d better be praying.
Korea, I’ll never stop buying
Kor-re-a
KOOOOOOREEEEAAAA,
KOOOOOOREEEEAAAA,
KOOOOOOR – EEEEEEEEEE—– AA KOR-EE-AAA
<>
Only you, you’re the only set I’ll buy (from) Ko-rea
Every sound that you make, every Internet Handshake
All the ads I know you’ll make
Sell me
LG LG
And there’s just this TV from Korea,
Every set that we see’s from Korea…..
Tonight
Tonight
We bought a set tonight
And now there will be no dead air time
To-night
Tonight
I’ll program it tonight
Or the stars will stop there where they are
To-day
The minutes seem’d like hours
The hours went so slowly
And yet they’re in the cloud
To-night
Tonight
The LG’s gonna route
Toooooooo niiiiiiigggggghhhhhhhtttttt
(now I’ve got the whole show in my head, e.g.)
The Set Sone (the jet song)
Someone’s Buying (something’s coming)
I Like to Buy in Amer-i-ca
SPOOL (Simulaneous Peripheral Operation On Line) COOL
Make of our LANs, one LAN (one hand, one heart)
I Feel Bit-ty
Somewhere (there’s a space for us, etc.)
A Set Like That (Seemed like it was in 12 flats when I was doing the show)
(sorry, I used to do a lot of musicals…).
Erm, Set Song….sorry
Hoverman from copper tape on foam core board.
https://macgyverisms.wonderhowto.com/how-to/build-20-super-antenna-for-better-signal-strength-more-free-broadcast-tv-channels-0146459/
@Jeff:
Now you’ve got me humming ;-)
@Jim2:
Hmmm…. I suppose Fry’s ought to sell copper tape… or maybe I can use my 12 gauge wire under Duck Tape… you can make everything with Duck Tape ;-)
@All:
Grousing about the lack of Goezintas and Goezoutas on modern gear reminded me of The Bone Pile. Off he went on The Quest… (Musicals do this to me ;-0 questing and all…;-)
Out came a long abused combined VHS / DVD player where the DVD door no longer opens, BUT, it has a lot of connectors. Newer Sony DVD player to L2. Second gizmo to L1. Antenna to, well, antenna, then recorder to “Antenna in”. Now I can at least get the old VHS tapes and the DVD player workable, and via a remote too. Yeah… no spousal plugs lesson (and attendant scorn… ;-)
So I can take a bit of time to research / buy Composite Video mixers and such. The sound is “good enough” from the set that I’m OK with it taking a while to find a better sound out solution. Besides, I mostly use the Other Set and it does have a phone mini-plug out. ( I chose it for that reason, and chose the LG knowing it had none ).
Maybe I ought to write LG a letter and let them know how a 20+ year old VHS Recorder “Improved their product” ;-)
EM – maybe another converter box may be useful. There are HDMI switches that connect multiple inputs to one output, The one I have has 4 inputs to 1 output and push-button switches, does not need a power supply, and was needed when the monitor I was using as a TV screen had only had a single HDMI input. I’d said, though, that I’d get a new TV when a 32″ one got below 200 euros, and then my local supermarket started selling TCL ones for 199 euros and I went and bought one. I’d been using a 26″ Cibox monitor for the TV screen since I only needed satellite, so that moved to the desktop computer screen instead and the 19″ monitor from that moved to replace my daughter’s CRT. Having started a long time ago with a 5″ monochrome CRT as a screen the real-estate is luxury and there’s no longer so much annoyance from the lousy programmers that misuse the screen-space.
Yep, I’m happy with the TCL TV and it’s got enough inputs to remove the HDMI switch from the system. A better sound system might be nice, since the speakers are pretty tiny and it’s not that loud at full volume. Good enough for most news, though. It also doesn’t complain about not having a terrestrial aerial attached.
Another option for copper tape, is the high performance speaker wire where the conductors are flat ribbon wire rather than twisted wire. I used some recently to make a counterpoise for a CB antenna and it worked very well.
Radio shack (if you still have one open near you) used to sell the flat speaker wire. Best Buy etc probably also has it for high end stereos where they want minimum high frequency loss to the speakers.
You can’t stop progress do you…
Our magic boxes as I called TV’s and computer screens have become flat and mega big and now interact with your smartphone. Doing a great presentation has never been easier. I know this because I started with white boards and crayons during the second part of the past century and used everything that came up in between. This incudes bulky overhead projectors that required a station car for transport and lot’s of muscle power.
Today all you need is your smartphone able to make a “hand shake” with an available Big Screen or an USB stick to perform a perfect presentation.
The addictive aspect can’t be underestimated. Very difficult to watch anything else once you’ve been hooked up with a “Big Screen”.
The bigger the better not only goes for cars.
Who wants to go back in time…?
Jeff,
Thanks for the musical comment. West Side Story is my all time favorite musical…….even better than Cats.
It surprised me to find a guru like Chiefio uses Roku. I tried it several years ago and found the same problems our leader describes above.
I have a 1080p Sony Bravia that cost $2,300 only five years ago. It still works like it did “out of the box” with absolutely no maintenance. Given my hearing problems I have trouble understanding the audio but using my Sennheiser headphones fixes the problem. I threw away my Roku box and now use one of my spare laptops to run Netflix. When I first set this up Firefox would not run Netflix so I now use Chrome as my browser.
My Visio 4K smart TV does not need Roku as it can interface directly with my router. In my opinion Visio is a poor brand as it does not stand behind its product. While my Visio is still working, one of my sons bought the exact same model and when it died (three months out of warranty) the only option that made any sense was to put the TV in the trash and buy a new TV from LG.
@R. De Haan: the Opaque projector was the behemoth in my past.
@Jeff: well done lyrics. I could just about see Natalie Wood on the fire escape, Jets lifting Sets for fun and profit.
@Chief: I recommend the HDMI switches, simply for plug-and-playground flexibility. Its one of the built-ins of my Surround receiver I have always enjoyed. i predict that you’ll be soon getting sw to allow multiple PI computer outputs to simuldisplay with internet news, streaming sports and the home shopping network… /exagg for fun.
Oh, and on the topic of compensation for hearing loss: when it comes to human speech, 5000 Hz cutoff is not an issue for intelligibility. Disregard if you Already grok vowel formants, but What is far more important is the frequency ranges used in human voice vowel formation, especially for the 2nd formant. Additionally, the hot spot of hearing sensitivity is about 3KHz. If sensitivity has been attenuated in this area, a little EQ will help bunches,
Fun so far reading about your adventures. All the best.
Well. I just hooked up my smallest “on the roof” antenna. One of those little 4 element jobs mostly used for FM radio. It has about 50 feet of excess coax on it, too (since that was what I had laying around when I put it up decades back).
Now I’ve got about 50+ MORE channels on the Toshiba in the bedroom… about a dozen of them in Vietnamese and about 20 in Spanish…
Guess that pretty much proves that just putting a new downlead coax on the ‘dozen or two’ element Log Periodic will be “enough” antenna for the living room ;-) Given that I’m already getting San Francisco stations (about 50 miles away) with the dinky one that is pointed more east than north (at an old very weak jazz station from the ’80s… don’t ask… I think it’s now country and western…)
Guess it’s time to go “up on the roof top” and do some measuring and plumbing of cables…
Status Update:
As of now, I’m about 20 times over supplied with channels. The LG has most of what is really needed in the way of “digital apps” since Netflix seems to be about 80% for us at the moment. Using Chrome on the Toshiba also supplies Netflix to it, along with my favorite internet news stations. After that there is Crackle and who knows how many more similar “Apps” for channels in the App Store. I don’t have time to find and sort them all out! Finally, the Roku is just an amazing flood of channels. I’d guess maybe a dozen of them are really important to me (the obligatory Netflix, a half dozen news, a couple of Catholic channels for the spouse, and then maybe a half dozen “other” channels – so far.) I’m figuring it will take me a year just to figure out what channels I’m never going to watch in the flood of channels.
At this point, with one more cable to get the local CBS station for the NCIS program the spouse insists upon, I’m no really needing the Satellite Dish for anything but Fox News and Fox Business. Fox does have an internet presence, but it is mostly a “chopped and formed” bunch of ‘couple of minute’ chunks out of shows; and a limited set of shows at that. Sorry to say it, but I’m going to be OK with not watching Hannity, O’Reilly, Kennedy, Varney, The Five, etc. etc. Since I want “whole shows” (the editorial work of assembly and editing does have value…) and not “show confetti” and for that you need a “provider login”, it will just be something where I need to ‘let it go’.
At this point, I’m not even sure something like Sling TV is needed, so even IF it is usable as a ‘provider login’, I may not have it.
Frankly, after a turn around the (very rich and deep) internet news sources, and a few hours of Netflix for entertainment: I’m pretty much tapped out of TV time for any one day. Full enough it, well, full. And with that, I’ve still got about 320 Roku channels, a dozen+ Chromebox channels, and 50+ over the air channels that I’ve not even looked at. (Not to mention the dozens and dozens direct to browser like all those local TV news shows and all…)
OK, how would I rank the order of importance?
#1) Get a Roku. It’s a giant flood of choices for nearly nothing in cost. You CAN pay extra for pay channels, but I’ve not needed to yet (other than Netflix that we already have).
#2) Given the experience today, Get that external antenna hooked up. Even a crappy one.
#3) Find a way to plug in a media savvy computer. Doesn’t need to be a Chromebox, but something with a keyboard ( I got a Logitech one with trackpad aimed at “PC TV” stuff…) makes that whole world of Youtube and similar stuff available.
Last) Whatever “Smart”s are built into the TV itself. Frankly, I’d just get a dumb TV and a Roku. Then you can isolate the TV stuff from the Roku stuff, having 100% control of when the Roku gets power. I only got a “smart” LG as it was what was on sale very cheap. I’d not pay $50 extra for a “Smart TV” when that same $50 gets me a Roku stick. Since the 4K Roku is $100, it might be worth it to pay an extra $50 for a 4K TV with built in Roku…
Then plan to spend a year or two figuring out all the channels and choices you have… THEN think about buying some…
@G.C.:
The Roku is for “quantity not quality”, but IMHO well worth it. Frankly, for me, I start each day with it and a round robin of 1/2 dozen international news sites. Now if you want the USA network or the local weather, that’s harder… The spouse mostly just uses Netflix (so it is the FIRST thing on the listing). After Netflix and the News, well, there’ s another 300 of “stuff” I sometimes wander through for particulars.
Now the LG “smart” TV also has that Netflix built in, but mostly offers D.W. for news (or at least I’ve not found A.J., France24, Sky, RT,…) and is much more limited on “Old Movie Free Stuff” – most everything I looked at wanting my money… So I’m happy to use the Roku for that instead.
@Steven F:
Mostly I only have intelligibility problems when sound level drops below my perception limit on kids and women talking softly in higher registers. Normal volume and men, no problem. Oh, and the way toooo wide dynamic range from Dolby decoders gives me lots of dropouts in soft passages or ears overdriven on loud stuff. I wish they offered dynamic range compression as a check box…
I’m going to have to try that spiral antenna. Great antenna site. Thanks!
@jim2;
You are welcome! I’m going to make one also. I wonder how the relative performance of the spiral vs the conical compares. I’ve not seen any dB comparisons, but my sense of it is that the spiral acts as a very broad band dipole (i.e. not a lot of gain, just a lot of broadband) while the conical versions act more like a log-periodic ( i.e. a series of dipoles each in front of the other, high frequency in front, low in back, with large directional gain).
I have this idea of making a PVC pipe frame, drilling 5/8 inch holes in it, and threading 1/4 inch coax in circles… Ought to be able to make a very nice UHF, but for VHF I suspect the coax will get a bit ‘floppy’ at the low freq end… so might need 8 legs instead of 4…
But picture a 4 joint center, then 45 degree angles into pipes about 1.5 meter long. Drill holes, thread cable (pre-made into infinite balun / dipole). I figure about 2 hours to make, minus glue drying time.
I DO need to get that old coax off the roof for play time ;-)
I haven’t done the calcs to see what size it is, but I was thinking more along the lines of just attaching it to a substrate, like foam core or some such. I’m making a bi-directional hoverman first, using foam board, but want to do the spiral also. I need to look for skinny coax. Should be easier to work with.
Check this out:
http://www.mouser.com/new/tempflex/tempflex_microminiature/
Available from Mouser:
http://www.mouser.com/ProductDetail/Temp-Flex/100065-0067/?qs=sGAEpiMZZMuwsoYAVCu3CI%252bzBb1wo3X%2fIQzsuyMecj8%3d
That first one required one to buy 100 ft. This one appears to allow smaller number of feet. 0.3 mm outside dia.
http://www.mouser.com/ProductDetail/Temp-Flex/50MCX-37/?qs=sGAEpiMZZMuwsoYAVCu3CL5ir4cJtvixqv%2f3mf6CD3Y%3d
“Skinny coax” is widely available dirt cheap. TV coax – 75 Ohm about $15 to $25 for 50 feet… less for shorter.
As the outside circumference determines longest wavelength and 3 to 4 turns is near the optimum implies that for a 2 M antenna you need about 7 feet for the outer turn, then likely about the same for the rest inward. A 15 foot roll ought to be plenty (so about $12 at Fry’s IIRC).
While 0.3 mm IS very thin, fatter antenna elements have broader bandwidth and intersect more total energy (generally work better in log periodic too since the best ones get fatter at the long end anyway – look up slot antennas…)
I’d just go for the skilly TV leadin for anything that wasn’t needing ‘way small’… like 10 cm wavelength.
Then again, for a nice GHz band antenna… ;-)
After looking at the formulas, I see your point. It appears the longer isn’t necessarily the better.
But what about the circular polarization? TV transmitters aren’t, are they?
I think circular polarization can receive any other polarization except the opposite rotation circular polarization.
@Larry Ledwick says: I think circular polarization can receive any other polarization except the opposite rotation circular polarization.
************
But won’t some part of the signal be lost because not “all” of it is polarized correctly?
I’m wondering if a reflector would reestablish the correct circular polarization ….
As with most things in the real world, TV signal polarization isn’t so simple.
http://www.tvtechnology.com/expertise/0003/circular-elliptical-polarization-for-tv/199673
LG, That is an interesting question.
A circular polarized antenna has the opposite chirality out the back, so the question becomes:
Does the reflector reverse the direction of chirality of an incoming wave?
I think the answer is yes. Why do I think that? Reflectors behind spiral / conical antennas increase their gain. Were the chirality anti sense of the antenna, it would do little to gain. That there is a gain says the signal is being absorbed and so is of the ‘proper chirality’ for the reversed direction of the backside.
One Major Problem with that reasoning: It is likely the dB gain was measured with linear polarized sources and they are absorbed by either sense. ONLY if circularly polarized testing were done would my reasoning hold… yet this one is typical in claiming big circular gain with a reflector
https://www.amazon.com/Circular-Wireless-HELIAXIAL58-Helical-Antenna/dp/B00GP5E9P6
so sellers puff?
Per equation 5 here http://digitalcommons.calpoly.edu/cgi/viewcontent.cgi?article=1062&context=eesp
it is the phase of X vs Y that determines circular polarization. Changing sign changes circular sense (chirality) see page 8. I think the reflector will change the sign on E(sub:oy) but while I think E(sub:ox) will also invert, I’m not sure what that does.
I believe that since the phases still vary in the prior ratios, it stays circular polarized, but with opposite sign has opposite chirality so couples to the opposite circular polarization of the reverse side of the antenna.
Given both theoretical considerations (even if tentative) and observation of actual device claims both yield the same answer, I’m comfortable claiming it is adding to gain.
@Jim2:
A circular polarization happens when the horizontal and vertical energy phases are out of phase (see the paper in the above link). Linear is when they are in phase. A circular antenna can “collect” any linear polarization (as it couples to some part of the antenna) and a matching circular polarization (as it matches the physical rotation). It can not couple effectively to the anti-sense circular polarization.
Since TV doesn’t know if you have a vertical whip or a horizontal dipole / log periodic, they go for a signal that couples OK to the majority, that are mostly rooftop horizontal (historically) which is why your rabbit ears often worked better slayed out sideways. Some places added some vertical (sometimes by accident…) for their antenna challenged locals.
The paper you cite goes for circular polarization as a new standard. I note in passing the claim that the FCC requires ‘right hand polarization only’ for circular antennas… One wonders how that can be implemented in a spiral that is one handedness out the front, the opposite out the back, but presume it mostly is about very high frequency things (where most circular is used) and with reflectors. (Thus yielding the potential to hide a bit of signal using left hand polarization as all those antennas looking for it are right hand…) but I digress.
But that aside: The simple fact is that right now today TV is mostly horizontal polarization and that can be best picked up with a horizontal OR circularly polarized antenna. The circular wound right hand sense if the desire is to pick up any OTHER circular polarized signals in the area, or left hand sense if you want to test the lower interference theory (or a flat pancake and swap sides for the reflector if you want to play with it… )
Chiefio,
Now that you have a large, full-HD (1080p) TV might I suggest a series of films on Netflix (I’m assuming you have the regular HD account) that will really allow that TV to “strut its stuff”? If you have not already watched these these films they feature the 1st-rate nature cinematography of Louie Schwartzberg.
– Moving Art: This is a series of 6 25-minute films. The first four in particular – Oceans, Flowers, Deserts, and Forests are real treats as they are set to the music of Ludovico Einaudi. There is no commentary or spoken words in these.
– Wings of Life: A 1hr 20 min film by Disney. This is narrated by Meryl Streep and has some of the greeny religion in it, but the fine cinematography more than makes up for that, imho.
CIO: I understand how polarization works. My point is that if a given TV signal is horizontally polarized, a spiral antenna will pick up less juice than a horizontal one.
CIO: Also, I assume the right hand rule applies to spiral antennas. If you have a stationary spiral antenna, the right hand rule will point in the same direction no matter to which side it is applied.
On a piece of paper, I drew a helix rotating in a clockwise direction to about the middle and place an arrowhead on the end. Then, rotate paper without picking it up 180 degrees. Draw a second clockwise helix toward the first and place an arrow at the end. Note they are both rotating the same direction, so they would impinge on the spiral in like manner.
For comparison, draw beside the first two a helix rotating counter-clockwise.
@David Young:
Yes, regular Netflix. Thanks for the pointer and I’ll take a look.
@Jim2:
Sorry if I implied you didn’t. I was just “thinking out loud” and I’m not great at chiral things (ambidexter and often get L and R ‘confused’ as they are ‘the same’ to me). So I have to work through those things more “by the book” and rule based sometimes.
http://www.antenna-theory.com/basics/polarization.php
confirms my speculation about circular reflections being opposite sense, so couple to the backside of a circular polarized antenna:
I suspect that the signal loss due to linear signal and circular antenna would be mostly made up by effective coupling to the Vertical component some stations broadcast in addition to the Horizontal and to the signals that have shifted polarization in the bounce off of objects.
As a variation of 3 dB is common between antenna designs, I think you will find a higher gain circular polarized conical easy to build and will make up for a 3 dB loss from circular polarization compared to something like a bow tie or fractal dipole, and especially so when the V component and the reflections are added back into the signal.
Just my speculation, mind you, and I could be way wrong.
One minor footnote: You can lose a couple of dB and up to 3 dB pretty easily just in added connectors and / or impedance mismatches. I’d take a 3 dB loss in the polarization and NO connectors for my coax until it reaches the TV over a linear polarized with 2 added connectors any day. Think Dipole to balun to coax to TV connector vs “coax to TV”.
Per the “right hand rule”: I think you will find that the opposite hand is needed on the back side of the antenna… Say the antenna is hanging facing N. The end of the outer loop pointing E. Now your fingers of your right hand would need to point E when your thumb points north, so RH polarization. Now to get a thumb pointing S, you must use your left hand with fingers pointing E… so LH polarization out the backside.
But like I said, I’m “chirally challenged” so double check my thinking on this as it isn’t a ‘flash’ based but a ‘rote’ based…
http://www.antenna-theory.com/antennas/travelling/spiral.php
Seems to agree with my reasoning, so I’m feeling a bit more confident that I’ve not got my right and left confused yet again ;-)
Looks like I’m the one chirally challenged.
Not at all… I just spent more time digging into it since I knew I didn’t know it…
BTW, my ‘flash’ said I ought to investigate angle acuteness vs number of turns. That paper that said 3 or 4 turns was optimal was measured on one relatively wide angle, IIRC (or maybe two). Intuitively, at very acute angles (like your log periodic VHF antenna) I would expect more turns to be optimal (like, say, spaced on the log periodic spacing of such a TV antenna?) while the more obtuse the angle, the fewer (like those shorty antennas with one director, a BIG reflector, and only one or two more in between). At least, that’s the “intuitive connection” between those log periodic / director-reflector-dipoles and the circular cone that “flashed” for me.
Exact design parameters to be driven by actual math and theory… So, for example, I have no intuition about “ought a ‘turn’ be on the log of the wavelength, or the 1/4 wavelength or…”.
But I’m pretty sure a spiral conical antenna of, say, 20 degrees or even 10 degrees could have a lot more turns than one of 45 degrees… Essentially, I’m speculating that there is a max range from min to max frequency that works well, and that range can be spread over a few turns in a very obtuse angle, or many turns in an acute angle. The limits being the dipole (as angle becomes 180 and frequency range becomes one) and the helical (as angle becomes zero and frequency range again becomes one). A dipole really only works at “no turns” or maybe 1/2 a turn for folded dipoles, while the helical just gets more gain and directionality the longer you make it (up to the limits of structural ability and resistance in the conductor).
That speculation would then assert that the 90 degree cone gives the widest possible frequency range with minimal turns, and the 45 to 30 degree range a good gain with more turns and slightly narrower frequency range (that then limits turns in a different way). Extending that, a 20 degree angle ought to take more turns to cover the available frequency range of the design point.
Then there is the remote possibility that the 90 angle is ‘special’ and doesn’t limit the number of turns at all. That you could spiral on out to as much acreage as you own and can build. Each direction, wider or narrower, tending more toward that “one frequency end” and so fewer turns fit inside the available bandwidth of that angle before they become too far as the outer circle approaches one wavelength spaced on a log periodic spacing. (An Archimedes Spiral may have different behaviour too, compared to the log spiral, with more turns before you reach one wavelenth outer size)
Or I could be all wrong and projecting intuitively something with zero basis in the actual physics and “the flash” is a “flash in the pan”…
I did the calculation for the simpler spiral. If I did it right, the spiral has a huge frequency range. I used Channel 2 at 54 mHz. At 30 times that, we get 1.6 gHz, more than enough to cover VHF-UHF.
Point being, if the conical has similar scaling, then you might be able to sacrifice some frequency range for gain. Not sure about the directional aspect.
Oh, and it is possible that the dipole isn’t the limit design at 180 degrees but the simple flat spiral is, and it can be infinite (to the limit of resistance of the wire…) but with poor gain, while the helix is the limit the other way with one frequency and lots of gain. Which would imply that for max frequency range you make a flat spiral, for max gain a helix, and for intermediate design points a conical spiral with angle vs turns giving the choice of gain vs bandwidth…
Or maybe not… it needs testing and some theoretical basis to know. (Or maybe I could just do more reading / think time on the papers I cited… I mostly stopped when I found the answer I wanted in any one paper. Reading all of all of them would likely bring me clue… if I had the time…)
I thought about a double, but oppositely wound, spiral antenna, both configured with infinite baluns, connected and used kind of like a double-dipole … or … whatever.
Also, I’m considering trying the infinite balun on a hoverman just for fun.
So it sounds like you’re pretty convinced the conical is the way to go. As long as I could get the best gain possible in two directions with about 20-30 degrees max db both ways, i would be happy.
I’m will probably try a conical, but like you I need to read a lot more since it has a lot of variables to play with.
Do you envision using a ground plane?
Haven’t read it all, but here’s design doc for conicals.
Beam antennas get their “gain” by narrowing the beam width, so for any given required beam width that you need to cover the stations you want to see, there is going to be a maximum gain you can have at the center of the primary lobe (and implicit in that an ideal number of directors on the antenna). Beyond the ideal number of directors (or reflectors) the extra elements do you little good. In the standard yagi array for example by far the most important elements are the reflector behind the driven element and the first director in front of the driven element, with the reflector being slightly more important than the director. At moderate frequencies most directional antennas get cumbersome beyond 4-5 elements in the vhf range and rarely go beyond 8-9 elements unless you go to very high frequencies but in those cases precision of construction becomes a challenge as the wave lengths get so short that even small errors cause big losses.
If you count each turn of a helical antenna as one element this satellite tracking antenna is a good example as they achieved more gain by stacking them side by side than by making one antenna longer.
That assumes you cannot hear a needed station using one of the minor side lobes which all beam antennas have.
Also maximum primary lobe gain almost never occurs at the maximum front to back ratio (ratio between the primary lobe and the rear lobe). If you have two stations one distant and one relatively near that you want to receive but on opposite sides of you, you can point the weaker back lobe at the nearby stronger station and the high gain primary lobe at the distant station. All sorts of trade offs here.
If your primary reason for going to a beam antenna is to block signal from an interfering station, then you will want to point one of the nulls at that interfering signal. By changing the dimensions slightly to detune the antenna you can move around those secondary side lobes a bit as well, so each situation is a bit different depending on what your geographical relationship is with the stations you want to hear in your particular location. As I mentioned in the past on one occasion I got best overall reception by pointing my beam almost 180 degrees from the station I wanted to hear which had the weakest signal, and got a clean reflection coming back to me from the opposite direction rather than a very erratic signal in the true bearing to the station transmitter.
https://en.wikipedia.org/wiki/File:Sidelobes_en.svg
Antenna gain is no so much that the antenna receives more signal over all, but rather that it compresses its radiation pattern either vertically or laterally so that all the signal it hears comes from a narrow cone. The tighter that cone and the weaker the side lobes the more gain the antenna has. As you have also noted that radiation pattern changes with frequency. An antenna might be a pretty fair directional beam antenna at one frequency and nearly omnidirectional on a frequency far from its tuned ideal frequency.
Try a different link to the same image (broken above).
@Larry:
The .svg type doesn’t display in WordPress (don’t know why) but other image types do. The link works when I clicked it though…
What you say is true of yagi type antennas (number of reflectors / directors ) but less so for log periodic arrays as they are a kind of ‘self similar’ antenna (“fractal”). Similarly, the spiral or conical spiral as “self similar” ought to have wider tolerance for more elements (my speculation…).
@Jim2:
WordPress seems to have swallowed your link.
Their are “spiral dipoles” made by using two spirals of opposite rotation. Also some made with square outline (discussed above somewhere… or in another thread…) One that was an under carpet square spiral (one of each sense) for SW.
IMHO the world divides into single spirals of one wire, two of them joined as a dipole feed;
or
two interleaved spirals of two wires of the same sense with the ‘feed’ at the center (though it may come in via the end as an infinite balun…)
The former seems to show up more at SW frequencies (and very large sizes) while the latter seems more common at VHF / UHF frequencies as a directional antenna (conical frequently).
Then there are the helicals where the reflective ground plane is attached to the coax shell and the center wire attaches to a helix of one wire, one sense, and one diameter; but with gangs of them to increase gain. Mostly used for satellites at UHF and above as you need multiple wavelengths of length to make decent gain so they become huge at lower frequencies.
I plan on a simple two wire single sense (right hand) conical with infinite balun as my first try (though I might do a planar Archimedes first just because it is so fast to build and simple – and in that case I’d make one of each ‘sense’ and connect them in a dipole arrangement to a balun to coax) It will depend, to some extent, on what happens when I start making the cone support ;-)
IMHO there’s a theory to be developed here that starts from the simple dipole, and then looks at what happens as you spiral it in the flat plane, vs spiral into the helix plane, and then vary the angle on the helix from flat (180) to zero (helix). Take the formulas for those different antennas (spiral flat, spiral conical, helix, dipole) and I think there’s a larger more complicated formula that can be derived to describe them all as limit cases. Just a hunch… Then make one side of the dipole a ground plane and repeat – that ought to bring in vertical whip and helix with ground plane reflector and… Pretty soon one ought to be approaching a universal antenna formula…
Probably a week or two of work… if I had the time. Would be easier with an antenna lab and / or even a few basic signal strength meters… Oh Well.
all this talk about antenna design got me looking at an add on WiFi stick that my grandson got me to extend the PC wifi adapter. A half inch diameter stick with a taper 1.5 inch long to a quarter inch diameter 1.5 inch long end. About 10 degrees. Don’t know what is inside the plastic case but would guess foil element. You have got me thinking about an off air TV antenna that I must create for my cabin. A tapered broadband sounds like a good solution for my needs…pg
Forgot to add, The roof is a metal covered 12/12 pyramid with a 2 inch hole in the peak for the leadin and mast, so adjustments can be made from the inside. The roof should make for a good broadband reflector under the elements…pg
Design doc for conicals:
https://www.hindawi.com/journals/ijap/2017/1691580/
10 simple steps ;)
Free antenna design software …
http://www.qsl.net/4nec2/
Here is a for-money antenna designer, but has a mind-blowing display of different antennas, some with radiation patterns or other data.
http://www.antennamagus.com/antennas.php?page=antennas
@Jim2:
As I understand it, the flat spiral and conical spiral have the same bandwidth characteristics, but the conical has a narrowing of the beam width, thus gain, from the smaller turns acting as directors and the larger as reflectors, at any given frequency.
So if stations are all around you, but not too far away, and in about a 70 degree spread on that axis, the spiral flat wins. For stations on one axis far away, the conical wins, and if only one direction on that axis, the conical with ground plane reflector wins.
Oh, and if only on one frequency, the straight helix of multiple wavelengths with reflector, ganged…
BTW, the 3dB loss of linear signal to spiral antenna can be very easily made up with the conical, or just using two of them in a single array.
Then the next variation to explore if I had several lifetimes to play with this stuff would be a conical antenna where the “cone” is shaped more like the bell mouth of a trumpet, or the inverse were the vertex angle goes from a wide included angle to a progressively narrower angle (sort of like half an American foot ball)
Perhaps a hybrid of the three shapes with elements of each “cone” variation listed above ganged together ( in theory they would have different impedance plots and would fill in the dips seen in the plots in the conical design doc plots @ jim2 says: 26 March 2017 at 1:33 pm )
Same might be possible by stacking two or more cones with slightly different vertex angles.
Oh, and to gang spirals, just look at how helical arrays are matched and ganged.
@Larry I had the same thought about the value of, shaped cone over straight sided ones, but I am considering vertical over horizontal orientation and using elevation over the slope of the ground-plain to reflect the signal on to the cone. The shaping would concentrate the response to the frequencies needed ..pg
@Larry,
The idea of a bell shape is interesting. Ought to give more gain on a narrower beam at the higher UHF where losses are higher, with braoder beam width and less gain in VHF wher you don’t need as much gain. Also ought to shorten the length a lot as more length is used for the longer wavelength sections.
Last night figuered out that ch. 2 ought to be about 6 foot diameter while high end of UHF about 6 inches diameter.
Click to access B08p2.pdf
Terminating the discone with a hemisphere adds performance:
Click to access B08p2.pdf
From an 11 cm antenna if I’m reading it right…
Gee almost 2 orders of magnitude of frequencies…
@EMSmith; see a family resemblance?
https://pgtruspace.wordpress.com/2016/11/20/emf-thruster-really-works/
also of microwave frequencies.
As the frequencies increase, conductors become insulators and the currents flow over the skin rather then within the metal. The interface is on the surface because of the inertia of the metal atoms to respond to EMF influence. Hummmmmm…. I have copper foil in my stores. Wonder what I could create from that…pg
Current TV frequencies really cluster in just three bands, now that anything above ch 50 has been stolen for other uses.
https://en.wikipedia.org/wiki/North_American_television_frequencies#Broadcast_television
All in MHz.
54 – 88 (ch 2 – 6)
174 – 216 ( 7 – 13)
470 – 692 ( 14 – 50)
Adding in to ch 69 (some older station assignments not yet abandoned…) extends to 806 but locally only ch 54 was interesting at 716 MHz. Not far from the 692 point.
This implies a triband approach could be beneficial. 50 to 90, 170 to 220, 450 to 700 as more rund numbers and giving a bit of room for performance fall off at the ends…
About 40 MHz, 50 MHz and 250 MHz width each.
2 – 7 are all in one direction for me, IIRC, so a unidirectional like a log periodic cut to that range would be good. 7-13 in two directions 180 degrees I think, so simple dipole or maybe spiral flat on the same pole and matched feed. Then the UHF as a small conical spiral on a rotor… Spirals become much smaller if only UHF. With wide angle, likely to get all the ones I care about (something like a 60 degree angle N.
Ah, the answer to how ch 54 culd have been stolen, yet 54 KTEH is still on my TV:
http://www.stationindex.com/tv/callsign/kteh
Keep the call sign and lie about the real channel…
So the channel numbers no longer need to be the channel numbers…
Sigh…
@P.G.:
Yeah, similar. I suspect that rounded ends might make it do interesting things, too. Especially if one is rounded and the other not.
Oh, and having realized that ch. 54 was lying and is really ch. 50, I pulled up the “installation channel guilde” and IFF I’m reading it right, only channel 7 is actually ON the channel it claims to be. Looks like they tossed everything up in the air and made a mess of it. It also looks like they are slowly chasing folks out of the lower half of the VHF band ( ch. 5 claims now to be on a UHF actual channel per my ‘channel guide’)
So I now have a task of making a list of local “channels” and then mapping them to actual “Digital TV channels” so I can figure out what bands I really need for my antenna.
IFF they actually only start at physical 7, I can make a MUCH smaller antenna…
Gee… these folks seem to have picked a zip code somewhere near downtown as I said I didn’t want to share my location, but good enough.
https://nocable.org/availability-report/zip/95124-san-jose-ca
says that only ch 7 & 11 (and 8 in Salinas that I didn’t know was still on the air…) are in the VHF bands. Well, and Ch 35 that ought not to be, but it, too, is in Salinas and not something I’m really aware of.
So Ch 4 and 5 are now up in the UHF bands. What happened to 2? KTVU and on actual channel 48 per my “channel guide”…
Putting in an SF address:
https://nocable.org/availability-report/ljxd-100-main-st-san-francisco-ca-94105
Has it in UHF now too. Guess I don’t need to cover that 54 – 88 Mhz band at all…
Well that’s gonna make things a LOT smaller…
So actual coverage needed is: 180 – 210 and 470 – 700 (or maybe a bit less…)
Golly. Who knew… but it does explain some of the odd things where I was picking up Ch 2 a lot better than Ch 7 despite a very physically small antenna without good match to the lowest band…
Yes EM that was part of the rational to go to digital UHF, the channel spacings in analog vhf and uhf were too wide (to avoid interchannel interference with the technology of the day). By going digital they were able to take advantage of its higher selectivity and compress the band width each channel used significantly (easier to do at UHF vs VHF due to the higher frequency to get good sampling rate on video and sound). Then they pushed everyone out of the vhf band that they could (public safety went first — that is why they got moved up to 800 mhz) By using trunking and digital technology they could have far more virtual channels in less bandwidth. Plus they gained some other advantages, UHF is much less prone to skip transmission so unlike the days when some agencies used low band (~45 mhz) you didn’t have to worry about getting local signals in Colorado blown out by strong skip coming in from the New Jersey toll pike as the sun came up. The shorter direct line of sight behavior of UHF also allowed them to reuse the same band spectrum in nearby communities without problems.
Here you go folks just found this nifty site, you only need to put in your state and zip code for this signal plotter to function. I put in just that and specified an antenna height of 30 ft and it appears to closely match my real reception on the 3rd floor of my apartment complex. It also gives cross over info between the nominal channel (virtual channel) and the real broadcast channel for the stations.
You get an azimuth rose showing the true bearing from north to each station and a chart output.
http://www.tvfool.com/index.php?option=com_wrapper&Itemid=29
(as mikey said – try it you’ll like it!)
Using the above I have solved one puzzle for me, two of the channels I like to watch the most are actually from a broadcast location 63 miles from me and although they identify as channel 3.1 and 3.2 they are actually channel 23 (525 mhz), so now I know exactly where to point the beam for those stations. In some weather conditions one or the other drop out completely so would be nice to fix that.
Looks like about 5.5 inches diameter in the small end and 21 inches diameter in the long end covers the actual frequencies in use here.
5.5 inches diameter x Pi = 17 inches wavelength x 2.54 cm / inch = 43.8 cm inner circumference (and wavelength of high frequency ) which converts to 684 MHz per:
http://www.unitconversion.org/unit_converter/frequency-wavelength.html
While 21 inches diameter x Pi = 65.94 inches circumference x 2.54 = 167.5 cm that is 179 MHz so maybe a bit bigger needed, but I’ve not allowed for actual velocity factor and other details.
So call it 5 inch and 25 inch diameters for some added safety margin. That makes it pretty easy to wind as it is a little over a 2 foot square with a spiral in it. 3 turns would have a 167 + 43 = 210 cm inner and outer and about a meter in between, so call it 3 m of cable. 12 feet. OK, so buy a 15 foot std length and wind it…
Or get a 25 foot and wind 15 of it, with 10 to attach to the TV…
Use an 18 inch tall conical wrap for about a 45 degree cone for gain… 18 x 1.4 = 25.2 for the approximate expected diameter of such a cone, so close to the needed 25.
Is that a single wire cone, a double wire cone, quad wire cone, or the looped log periodic that you’re building. I’ve lost track.
If any of you want to play with a simple high gain yagi design for some hard to reach distant station, here is pretty nice quick calculator page that lets you play with numbers.
http://www.k7mem.com/Electronic_Notebook/antennas/yagi_vhf_quick.html
Here’s an example of marrying a gray hoverman with a yagi. It wasn’t straight forward.
http://technology.niagarac.on.ca/staff/mcsele/Antenna.html
@Jim2:
I’m just planning on a simple Archimedes spiral of 2 wires (dipole) to start. Then make a conical one. Then try a simple log spiral of 2 wires, and then the conical of it. All made with the infinite balun – all a single chunk of coax method from just above fig. 3 here:
http://www.antenna-theory.com/antennas/travelling/spiral.php
So take a chunk of coax about 15 feet long, at the 5 foot mark, open the jacket for a couple of inches, peel back the shield (from the TV end toward the far end) about 2 inches and fish out (cut at the far end) the inner connector. Solder inner wire (from toward the TV) to braided shield of the part away from the TV (then coat it all in spray on rubber or a silicone smear sealant). Now just spiral it (joint at the center of the spiral) into a flat equal spaced spiral (Archimedes) and run the long end out to the TV.
Repeat winding with a log spiral spacing.
Repeat winding on a cone of about 30 to 45 degrees center angle (maybe even try a 90) with both equal wire spacing and with log spiral spacing.
Basically, once the coax part is made, it is easy to test it as a simple free air dipole, and as flat or conical spirals in equal (Archimedes) or log spacing. Just don’t glue it down until you are done… (Duck Tape is your friend here…)
Wound such that the outer circle is about 25 inches leaves about 3 feet for the next two turns, one of them about 1 foot and the other about 1.5 long. (I’ll actually do a trial fit with uncut cable first to get the exact lay and length I like, and might even use more turns if I have a longer chunk of coax to start from.
Not planning anything with 4 wires, and the idea of a log periodic made out of loops is a concept or explanation, not a build. (The idea being that when you wind a conical log periodic spiral, and tune to any given frequency, the resonant spot sees smaller loops in front of it acting as directors and larger loops behind it acting as reflectors – basically an explanation and prediction about the log wound conical spiral having more gain than the Archimedes wound due to being an analog of a log periodic linear, only as a sprial.)
IFF the short conical log periodic wound coax based spiral (say 90 or maybe 45 degree cone angle) in fact has significant more performance than the Archimedes and flat log wound, then I’d be tempted to try a build of a multi turn log periodic spiral wound conical. Something like a 20 degree angle and a dozen turns. But that’s going to be like “real work” so even if I do it, likely a couple of years away. (Would need at least 3 booms, and not just a standard PVC pipe fitting to set the angle where the 45 degree is just an elbow joint; then the whole thing is bigger so more structurally challenged so likely schedule 40 PVC or added cross supports, all of which will make it heavier which ..)
Oh, and do remember I’m only playing with these spiral antennas.
On my roof is a very nice log periodic aimed at the major axis of stations and all it needs is a coax replacement. I know it works fine as we used it during the Analog era (pre satellite ).
There is also a fairly small ( 4 element? ) something or other (looks sort of log periodic, maybe) with a dinky UHF section that actually is in use now on TV #2 and ALMOST gets everything desired. It is pointed about 45 degrees off optimal as it was pointed at a jazz radio station decades back (said station now C&W I think). So it needs a simple twist to point more north when I’m taking down the old coax.
Given that, I’m not needing any indoor antenna and the spirals only matter as an item of curiosity.
Oh #2:
And for that coax, suspended in free air as a dipole, you can put a winding or three around ferrite at the ‘end of the dipole’ point toward the TV to assure that the two active outer shield sections are the same electrical length. I’ve seen that done when used at HF and VHF frequencies for HAM use. It likely isn’t needed at UHF and / or if you are not transmitting at power…
EM have you tried this station plotter to see exactly where your current stations are?
My plot came out with a lot of stations I did not know about, and my actual vectors are more wide spread than I expected. (it used to be common knowledge that all the stations were on the mountains just west of Denver but looks like the conversion to digital caused them to piggy back on lots of other antenna locations around the metro area after the folks on Lookout Mountain started complaining about the antennas (which had been there for 50 years).
http://www.tvfool.com/index.php?option=com_wrapper&Itemid=29
I used “nocable.org” but it has a nice map too. See my channel list a few comments up thread and scroll to the right. Notice everything is pretty much N, NW, SE etc.
Due to the geography here, and Sutro Tower in San Francisco, almost everything comes from Sutro Tower, with a very few from the directly opposite Salinas area. Not much “in the bay” and nothing “other side of the mountains” toward the ocean.
That just leaves Oakland side, which has one? maybe 2 or 3 with some UHF I don’t watch. It is “close enough” to the SF angle to not be an issue from “down here”.
Nothing due east (as it is mountains with few people) or west (as it is mountains with fewer people) and since both of them have major earthquake faults under them (thus the mountains…) not likely much will be built there either.
So I’m blessed with essentially a “due North / South” axis (really skewed, but you get the idea – one line) as that’s how the valley lines up. Then the one or two oddballs other side of the bay on a slightly North East line, but inside the acceptance angle for most antennas. (Anything actually IN San Jose, like the old channel 54 IIRC?, is so strong you hardly need an antenna anyway…)
Of course, this Antenna thread was bound to be prolific.
What else should one would have expected with a screen name of
We have the concatenation of Electro-Magnetism & Smith Charts
A guy called EMSmith Designing/cobbling Antennas.
The irony of it ;D ;D ;D :D
Don’t know if u guys saw this, but with a quad-spiral antenna, you can swap phase of one pair and change the pattern from max radiation in the “bore sight” to a null in the “bore sight.”
http://www.antennamagus.com/database/antennas/antenna_page.php?id=120
I’ve run into another problem I didn’t realize I had until yesterday. I have a Samsung “smart” TV, no microphone :), but it has no provisions to set a channel manually. So, going with a rotor is out. I would have to rotate, do a channel scan, then watch. I need to complain to Samsung!
I ran into that a few years ago on a tuner, if you lost the remote it was a door stop because there were not manual buttons to allow you to perform basic functions like power on, power off, up one channel down one channel etc.
Like building which no longer allow you to open windows when the AC dies, too much dependence on a single path of operation.
@Jim2:
That seems to be more or less the norm now on “smart” TVs. It’s biting me in that I have a VCR on channel 3 but if it is on to do the scan, it blocks the rest of the TV antenna signals… Yeah, stupid PITA.
@L.G.:
Yeah, I always liked that chart ;-)
@All:
From the “Well that was enlightening” department:
Up on the rooftop Smith he goes,
Down comes the frown in rust and dross…
I visited the rooftop preparatory to doing the actual coax replacement. What I found was a much bigger project in front of me.
Seems that in the “mere” 1/4 century since I did the install, the “300 ohm twinlead” portions of the baluns at the antenna have had the plastic turn to dust, and the combo of copper wires and plated iron nuts has decided to corrode horridly. Oh, and the 1/2 twist or so in the twin lead has caused the wires to be twisted together, only the corrosion preventing a dead short. Plastic on the baluns also showing pits and such.
So now I get to:
1) Find a LOT of rustoleum / penetrating oil.
2) Remove the rusted nuts holding the clamps holding the antennas to the mast. (and the ones holding lead-in wires to the antennas)
3) Take the antennas to ground level for a complete clean / spruce / de-rust and-or replaced cycle.
4) Completely replace the coax, baluns, etc etc.
5) Reassemble it all back up on the roof.
That spiral wound antenna up in the attic is looking better and better ;-)
The good news? Looks like my silicone glop over the coax ends and end of baluns has held up nicely and kept them waterproof. Also impossible to simply unscrew… Then again, since it all needs replacing, “undoing” isn’t much of an issue…
Given the condition, I’m frankly amazed that I’m getting the stations I do get through that rust pile at the antenna junction.
So don’t expect a lot of news about those particular antennas until sometime around the end of summer… At most I’m going to take the little one down and see how bad it is to clean up the connectors and test it out at about 12 feet high on a simple pole with 15 feet of coax out the window… The idea of doing derusting maintenance on an old antenna is not real attractive… Especially on what were, at best, modest antennas in their day.
Plans. Men, mice. Gang agley…
( I think I need to get a motorcycle leather jacket made with a big patch on the back showing a mouse or rat and with the word GANG on the top and AGLEY on the bottom… see if anyone giggles…)
Best penetrating oil you can use for that is a 50/50 mix of acetone and automatic transmission fluid, works even better than the commercial penetrating oil mixtures.
Good luck on that
Before I married my wife, I did not have cable at all. I just watched OTA TV. And yes, that was before DTV. Should I ever cut the cable (I do not care for it, it was mostly for the kids and wife), it is going to be interesting finding the channels! 3 is not 3, but 33. But 7 is really 6, and 12 moved to 23. Grrrrr!
@Phil; Yeah, I have exactly the same problem. Before satellite I install a nest of home made antenna with amps to get analog OTA. As we are in a hole, we got all the channels in northern California…poorly. Satellite was a great improvement in quality of the viewing. Now with digital I am tempted to go back to OTA to get out from under the rapidly increasing cost and deteriorating quality of the satellite providers offerings. Our old massive CRT analog TV died last fall and was replaced with a light weight digital flat screen, so OTA is again an option. Now just where is that old computer spread sheet antenna engineering file stashed? …pg
@Phil:
The digital TV tuners seem to be designed with this in mind. 54 still shows up on 54 as you run through the “dial”, even though now on 50, and channel 5 is at 5, even though somewhere up in the UHF…
That, frankly, is why it took me so long to figure out they were changed…
Interesting to note that, here, 7 is on both 7 and 38? so likely they are ‘in transition’ for that second VHF band… and ‘someday” an update will be sent to the computer in my TV saying “For 7, no longer tune to physical 7, but just go to 38 and SAY it is 7″…
@P.G.:
Consider that if you have access to the hill top, UHF will easily “bounce” off of a couple of feet chunk of metal. Consider putting a flat sheet of steel on a sheet of plywood (for stability) angled such that “bounce” points at the nearest concentration of UHF stations… (Or, alternatively, put a UHF antenna there and a very broadband amplifier in it, then point a dish at your place…)
Hey, Ham Operators work “moon bounce” and a sheet of metal is a better reflector and a lot closer than the moon…
EM some of those split channels are just repeaters used to fill dead spots in the coverage. I have that here, on some days one of the pair comes in best, on other days with different weather conditions the other is the best.
@Larry Ledwick – Re: TV Fool
That actually serves another purpose. It shows what the real station numbers are now!
E.M.
Ok, so how do they do that? Is it a signal embedded in the Digital signal (that would seem to be like closing the barn door after the cows have left) or a strict one-to-one translation (everywhere there is a 54, DTV now knows to display 54, even though it is scanning 50 for the channel).
I can see why they are doing it. However, at some point, you are going to need a PhD to figure it out. Best to just cut the rug and call 50, 50 and whatever was 5 is now 32 (or whatever).
I think the point is that this is locally determined to avoid interference between channels and nearby stations serving other areas.
Presumably someplace the TV accesses a lookup table or when it decodes a signal when it does its channel scan, it is told in the encoding data what the public channel nomenclature will be for that channel regardless of what signal frequency it is actually on.
This is interesting. ATSC 3 standard includes video and audio watermark specs.
http://atsc.org/standards/atsc-3-0-standards/#.WNxbGd_6zRY
And now for something completely different … hacking via rogue TV signals …
https://entertainment.slashdot.org/story/17/03/29/2018240/about-90-of-smart-tvs-vulnerable-to-remote-hacking-via-rogue-tv-signals
Watching Lady Gaga Super bowl halftime show on the Roku… via a “cast” from my tablet..
Download the TV Cast app for Android, and the matching TV Cast on the roku, and away you go.. So this is a Youtube found via the tablet, then it gets chucked over to the TV full screen and the tablet is out of the loop and free to do other things…
Also downloaded a ROKU Remote ap that turns the tablet into a remote control AND lets me have “private listening” via tablet speakers OR tablet bluetooth… so I can now put my bluetooth headset onto my non-bluetooth TV. Nice.