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Wacky JFD part 2
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Here is an example of the quest to boost high-band gain by adding antenna bling in the form of folded dipole loops tuned for high bandAttachment 176779.
This is a later version of a broadband VHF antenna Attachment 176780 using a helical high-band (zig-zag) very common in the early 1960's. Both these VHF antennas have companion a UHF antenna. This is none other than JFD's unique version of the super-efficient bow-tie corner reflector. |
Happy new year
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Channel Master - much more to come but here is what I consider to be the ultimate and most beautiful sight on a rooftop circa 1970
The 4311G UHF adjustable yagi and 3611 crossfire VHF pictured below are on a 50-foot wood pole in a nearby neighborhood. No rotator, these beauties are aimed toward Philadelphia 60 miles away. Back in the days of analog, this returned at least 0 db crystal clear pictures on 4 VHF and 3 UHF (independents) channels, no doubt. Just a guess but the owner probably did not care if they watched the local affiliates, 1 NBC, 1 ABC, 1 PBS and 3(!) CBS stations. A second guess, this pole with climbing arms, was also climbed more than once to replace a dead mast preamp! Attachment 177405 |
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Thanks DavGoodlin, for the photos and comments. Hope you do have some more to post. Fond memories of studying those TV antennas while riding in a school bus. Practically memorized shape and configuration of every antenna along a 8-10 mile rural route. Alas, they are gone. Never had any photos. In searching for TV antenna info, realized that there was very little published in the 1960 thru mid-1970's (the peak of the large TV antenna days). Much TV antenna development was done in the 50's and there were a couple of books that recoded some of that development. Seems to be some history and technical details lost, or nearly lost. Quote:
Don't think there was much available in preamp lineup in the 60s. Vacuum tube type set-top tunable boosters were used before transistorized antenna mounted preamps became available. Guess those fared better with lightning, hey, they could probably make some sparks of their own. |
Very interesting thread. When I was in Florida a few years ago I was fascinated by the VHF/UHF TV antennas in the sticks away from the cities, I presume cable didn't get to them. Here in England most folks don't have cable (about 15/20% have cable) & most houses have a UHF TV antenna on the roof (mostly yagis) you never see VHF TV antennas anymore as VHF hasn't been used for TV (it was used for 405 lines) for over 40 years, most people changed to UHF (625 lines) in early the 70's as colour was never broadcast on VHF. When we did have VHF TV most antennas round here (Nottingham area) were H or X shaped for low band (band 1) & 5 to 9 element yagis for high band, (band 3) both were verticaly polarized, the 2 transmitters were just north of Birmingham about 45 miles away..
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For amplifiers I recommend a GaAsFet one from
http://www.advancedreceiver.com/page12.html and get one tuned to your worst case channel. The noise figure of these is 0.5 dB!! They also make broadband ones but the noise figure is 2.5dB. That can make a difference. These do need a separate wire for the DC feed and a weatherproof box. Their overload capacity is stupendous. As for antennas ... I was trying to get a channel 44 which is 68 miles away over a tiny hill. What worked best was a home-made cut to channel 24 element Yagi, scaled from a design found in a 1977 ARRL handbook, make 100% out of copper tubing soldered together. This was at a height or only 20 feet. Such antennas are 6 channels wide. I added an extra reflector behind it cut to channel 19 and that made it work fine for local channels 17-23 (of course at low gain, the reflector just removes the back response). |
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Odd looking UHF Antenna
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Here is an odd looking old UHF antenna that I got at the Early Television Convention in 2013. I use it with my big screen 50 inch plasma, and it works better than rabbit ears. Just had to use a matching transformer for the 300 ohm to the 75 ohm coax connector. It just sits on top of my Technics turntable, and brings in good hi-def picture.
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DavGoodlin; That is quite a interesting group of antennas you found. I'm looking
forward to more on this, and thanks for posting it all.... |
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To continue with more from Jerrold, attached is a "showroom sample" Zenith antenna, circa 1979. This was used to sell its unique features up close.
The bowtie has a Z cut into it. The X-director element(s) is a classic Jerrold design as well. Notice the notches in the director element so it can be shortened and optimized for high UHF channels. This antenna seemed to be in production for only a few years, after which only Channel Master and Winegard survived the late 70s. Attachment 188665 |
Antennas I have photographed
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TV Antennas have held an interest for me, since I was a small child, I have always "looked up" whenever possible, to see antennas in different areas. I find I still look for them, when I'm out and about, especially walking from my truck to the home, at Estate Sales. When I see one I like, and I'm safely able to (I.E. not driving:), I will snap a picture with my cell phone! Here are a few I have taken, in the last several months. The antennas not on towers, are in the Suburban Detroit Metro area, where I live, and the fringe area tower units, are in outlying areas, some near mid-Michigan.
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Dave
The first is a classic Radio shack (Antennacraft-made) design, now used by Channel Master since CM limited their line significantly. The second is fairly new. The third pic is an old VHF setup for channels in opposite directions so a rotor is not needed. The fourth one is very interesting, a stacked folded dipole with multi-element reflector array. I have seen those but the camera was not handy. The fifth picture seems to show a Zenith on the left, on the right is the good old CM crossfire VHF topped with CM's version of the 4-bay bowtie. Looking through some JFD literature, I noted that the longer elements were not only 1/4 wavelength for low band VHF but were at 3/4 wavelength for high band also. That is how the stacked conical antennas functioned on high band with no short elements. Thanks! |
My house has a wall plate in the living room for some kind of antenna..one of these days I need to climb up in the attic to see what's up there.
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Picture #4 is an early 50s Channel Master 2 stack "Champion", which was available in single bay, double and quadruple stacked versions. Each bay consisted of 2 high band folded dipoles and a low band dipole, backed by 5 reflector elements. If you happen to have a Jan '54 Radio Electronics (15GP22 screen shot on cover) it is pictured on page 22 CM ad.
jr |
Possible could be a radio antenna, Tom, I suspect its TV, though, It looks newer, if it was original to the house they would have lined up up with the power outlet 6 inches away from it., has a 50's or 60s style wall plate, 2 slots, almost the same size as a 2 prong power socket, but set vertically in the middle of the plate. Its a bit odd, doesn't match other antenna outlets I've seen.
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I picked up this UHF antenna at an estate sale today. I don't know the age but guessing by all the other items in the house it probably is from around 1950-1970. Any ideas?
http://i290.photobucket.com/albums/l...b/IMG_2437.jpg |
No idea what it was sold as, but its a fairly "standard idea" design related
to the very common Radio Shack double bowtie. I've simulated and actually tested many related designs similar to both the RS and that one ... and they are truly stellar performers. The strange shape of the driven element actually simulates AND TESTS .... as quite optimal, clearly better than flat (if you need to cover a wide frequency range). |
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http://www.radioshackcatalogs.com/html/1974/h083.html . |
Sony's VCA-4 automobile television antenna is a weird one. I guess it worked great when you were travelling but unless you had antsy kids in the back, wouldn't it be a little hard to watch? ;)
I put magnets in mine so I can stick it to my car's ragtop. Officially the last guy in town doing that. http://i11.photobucket.com/albums/a1...y/IMG_9249.jpg |
Probably worked better than those boomerang jobs
especially on VHF. |
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Judging from the length, it looks like a low band VHF 2-6 Yagi with two folded dipole driven elements, probably to spread the useful frequency range.
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It would be interesting to plug the design and dimensions into some modern day antenna modeling software.
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IIRC, some marketing people dubbed this a "NEW, IMPROVED TRIPOLE DESIGN" :D ... Supposedly improved the impedance matching of the two DEs to 300 ohm line. :scratch2: jr |
I had the same kind of RS antenna on a rotator. I got up to 175 miles reception. I lost it and would give almost anything for another.
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300 ohm twinlead will give you the perfect chance to resurrect another 1950s practice: aluminum foil wrapped around the line and sliding back and forth to tune/detune any mismatch. :D Of course, you cannot get the fine feedback with digital that you could with analog. :no:
I was so happy when they got rid of that stuff. Prone to picking up local motor interference, and needed to be spaced away from metallic antenna support structure. The town house I moved to in 1974 had a pre-installed VHF folded dipole in the attic, with twinlead of course, to a living room antenna outlet. Couldn't understand why it was SO lousy until I traced the twin lead and found it was routed through the wall by wrapping it around a convenient electrical conduit. |
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Hi All, i'm a little late to this party, but i thought i would post a pic of my 60's UHF twin bow tie antenna that i still use today.
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I have built several of the biquad antennas, and indeed they seem to perform best with short reflector spacing. http://martybugs.net/wireless/biquad/ https://buildyourownantenna.blogspot...alculator.html jr |
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Many apartments had only VHF-only MATV systems, and that little wonder usually pulled in at least two of the three Philadelphia independent UHF stations, provided you were up a story or two and facing the right direction. |
Lucy Puts Up a TV Antenna...
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First aired, 26 November 1962. Antenna? Wineguard?..
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BTW, where's the transmission line? :scratch2: |
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I have seen a Winegard like that, the Powertron P-55 or without the amp, Colortron C-42. My grandma got one out up after the 1971 Chromacolor was delivered. The model was made for decades as a workhorse where 3 or more VHF channels in the same direction made a broadband VHF necessary.
In most areas from 30 out to 55 miles, this antenna with a 5-foot boom tended to perform as well fringe-rated log-periodics twice that size and compared without the amp! JFD, Jerrold and Channel Master did not have a smaller budget model that would work like that in a standard fringe location. Of course, if directivity and ghost rejection was criteria, the biggest antenna is the best. In the 80s and 90s, the VHF-UHF chromstar line was a huge seller but a variation of this little wonder was still available in "TV man" line and I have one of those. Gone are the "W"s punched out in the rear driven element bracket you see. That was 1962 and what I like about your pictures is the three-phase high tension lines and cross-arms look awful close, probably to embellish the folly of Lucy on a roof, though its clearly on a movie set Attachment 197538 |
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A couple antenna pictures here, I took just the other day. Each antenna, I have seen for many, many years, but finally took the time to take pictures, especially since the tower on top of the Sears store, which closed a few years ago, who knows when all will be torn down. I'm always looking for classic antennas! I wish I had one, like the folded dipole with reflector, which looks like it's mounted on the power pole, but actually next to it.
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I was playing around with it in 2005-06 trying to recieve analog UHF, this was my millionth attempt at having UHF at home. I could get a few stations one really clear a few miles away at a roadside lookout with a pocket tv, but I never did pick anything up at home. To many mountains and trees where I live and they completely kill UHF signals. God I sure miss analog.... |
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