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  #31  
Old 09-07-2012, 08:59 AM
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Jerrold - Zenith of antennas

With my tower installed over a month ago, I have been testing different UHF antennas to see what I should ultimately install for long-term use.
I stick with one target channel, DT31 which is my location's weakest signal from Philadelphia. The recent muggy unsettled weather makes for great worst-case OR d-x scenarios that seem to vary daily.

I started with a Digitenna D-UV as a base. This is a decent product made in Wisconsin, but pricey. The design uses RCAs bow-tie design mentioned in a previous post to good advantage in a relatively small package.

I next used the classic S+A UPW (relatively flat response) from the late 60s. It was nearly the same as the D-UV, a real testament to an old classic.
S&A UPW.pdf

After a week or so, I ventured into my garage attic and found this, a Jerrold variant of the corner reflector with a very interesting design.
This was mainly seen on commercial-level MATV installations and looks like something Blonder-Tongue would make today and sell for big bucks.
It has a 4 foot high semi-parabolic (in vertical plane only) reflector, a design currently being sold as an attic antenna under the GE name at Mal-wart. The real key to its effectiveness, or efficiency if you will, is the driven element design, not found in the GE-marketed version. The simple bowtie has top and bottom horizontal "tails" and is "grounded" in the center of each half by stand-offs of critical length.
Attachment 176080
It is no wonder Jerrold was chosen as OEM for Zenith's line of antennas in the 70s!
Also small wonder Jerrold's PIX series VHF design lives on in the VIP line by WADE antennas of Canada.
After installing this Jerrold and seeing excellent results, the subsequent three "fringe" UHF antennas I have left to try may well be out-shined.
This ad from 1969 shows a cross-section Jerrold's line Jerrold.pdf

A reality check here; Nothing has been known to beat a full Parabolic, but being currently UN-available and a freaking beast to ship/install, its mentioned only as a point of reference as we seek the "second best" and practical solution.

Regarding mast-mount pre-amps, I prefer to use something new.
The older ones seem prone to PS transformer failure AND of course "overload or poor image signal rejection" from strong FM stations.
I tried the Winegard AP-2870 (separate U and V antenna inputs) and then tried the Channel Master 7777, with similar features but more expensive rugged construction. Both performed in a similar manner, but when I did the same comparison on my CM 4251 Parabolic (installed in a secure but low elevation), the CM7777 produced a stronger (probably cleaner- per the CM-7000 DTV box) signal*

*I should have a Sencore or B&K ($1000 at least )spectrum analyzer to do this properly. DTV boxes do not report signal level but rather bit-error rates, which are affected more by multipath than strength.

Last edited by DavGoodlin; 09-28-2012 at 03:29 PM. Reason: Jerrold Ad 1969
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  #32  
Old 09-08-2012, 08:23 PM
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If you go to the irvington flea market in indianapolis indiana booth 79 has 1950s rabbit ears 10-15 dollars each!
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  #33  
Old 09-11-2012, 11:06 AM
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Originally Posted by radiotron View Post
If you go to the irvington flea market in indianapolis indiana booth 79 has 1950s rabbit ears 10-15 dollars each!
PM me with some pictures, I am looking for a 1965 Rembrandt with a translucent dark-red housing

I seem to have given all mine away when I sold TVs to the less fortunate.
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  #34  
Old 09-18-2012, 10:14 PM
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This thread encouraged me to finally get off my duff and set up my outdoor antenna. I had been making due with an "oven rack" UHF hanging in the attic. I had everything I needed: a pretty high-end, fairly late model Winegard that I had picked up a few years back at the local freight salvage store (installed on the back of my shed, hardly off the ground and with mast supports so badly twisted by a windstorm that it was almost vertical), a NOS Channel Master chimney mount kit, bought new by somebody in the early 60s at Atom Electronics of Lancaster, PA (how ya like that, Dave?), a used 70s vintage Alliance rotor, and plenty of coax. I got it mounted last week and have been slowly getting things set up. Issue #1 right now is that the bedroom TV is seeing too much line-loss due to the goofy way I rigged things up. For some dopey reason, when we added on I ran the coax from the bedroom through to my TV room, not up through the attic or down through the crawlspace, but through the studs where I can't access it. At least, I think that is how I did it. The coax has to run down into the TV room, through an outlet, then another short piece of coax connecting to another outlet that runs to the bedroom. Oh, I do have one of those 20db amplifiers in the mix back there. With that setup, and the antenna aimed towards Baltimore, I can't really pick up anything. But the living room set, seeing almost a straight run, gets pretty much every channel from the city. (but with help from another 20db amp right before the TV, and yet another one up in the attic!) So, got some cleaning up to do. What do you guys think about an antenna mounted amp? Any reccomendations as to make/model? I played with one a long, long time ago, from Radio Schlock, but it didn't last long.
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  #35  
Old 09-19-2012, 12:00 PM
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Every time you amplify a TV signal, you will add more noise. However, I'm surprised you need two amplifiers ahead of your large outdoor UHF antenna just to get Baltimore stations from where you are (TV Guide's website shows Baltimore-Washington area stations as being the default stations for your area). Also, I am wondering why you don't get anything on one TV (yet the living room one gets all the Baltimore stations) if you are using the same amplified antenna system for both TVs in your house. If it works well for the living room set it should work equally well for the other in the bedroom, or wherever your second TV is in the house.

BTW, I wonder if the Baltimore TV stations are all on UHF DTV allocations, or if some few are still on VHF channels. I ask because, here in northeastern Ohio where I live, two stations -- Fox channel 8 and CBS channel 19 -- are on VHF DTV channels, while every one of the others (3, 5, 25, 43, 61) are on UHF allocations. This means I can get the UHF ones but not the two on VHF channels (I was using a small UHF only DTV antenna at the time, about a year or so ago). If the two VHF DTV stations were independents or were affiliated with networks I don't watch, I wouldn't mind that I don't get their digital channels, but these two stations also carry my two favorite retro-TV networks (MeTV and Antenna TV) on subchannels 19.2 and 8.2, respectively.
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  #36  
Old 09-19-2012, 12:46 PM
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Been on the lookout for old TVantennas in the neighborhood. Not much left anymore, but I do notice quite a few of the remaining Log Periodic and Yagi antennas pointing exactly 180░ backwards, with the big end toward the stations. Oops.
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  #37  
Old 09-19-2012, 01:08 PM
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Quote:
Originally Posted by Ed in Tx View Post
Been on the lookout for old TVantennas in the neighborhood. Not much left anymore, but I do notice quite a few of the remaining Log Periodic and Yagi antennas pointing exactly 180░ backwards, with the big end toward the stations. Oops.
Many people made that mistake with LPV antennas, thinking the large end of the antenna shaped like an arrow is the end to orient to the stations' towers. Of course, as you said, this is exactly 180 degrees opposite of where the antenna should be oriented. I remember reading in an old electronics magazine (I forget which one) the story of a TV repairman who made a house call for a TV that wasn't getting reception from any of the local stations. The technician found the problem in five minutes; the large roof-mounted log-periodic all-channel antenna had been installed with the large end pointed at the towers -- of course, exactly 180 degrees away from where it should have pointed. He mentioned this to the set owner, who answered (in paraphrase), "I always thought these new TV antennas were supposed to be installed with the large end pointing at whatever you were trying to catch."

BTW, I know what you mean about old rooftop TV antennas disappearing. I live in a very small town (population appoximately 3250) in which most of the homes and apartment buildings (including the apartment building in which I live) have done away with antennas, and are now either wired for cable or satellite TV. (My building has cable.)

There are very few outdoor television antennas to be found in this town, and those that are still standing are falling apart. There is one house down the street from me that has an all-channel TV antenna which is falling apart by degrees. It has already lost the first two elements, and the ones behind it are so loose that one of them flaps in the wind. I expect that element to blow off entirely in the first big wind or snow storm this winter (I live near Lake Erie, so we get very fierce winds right off the lake every year; that antenna likely will blow apart very soon, the way it's going now).
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Last edited by Jeffhs; 09-19-2012 at 01:28 PM.
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  #38  
Old 09-19-2012, 04:47 PM
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Quote:
Originally Posted by bgadow View Post
What do you guys think about an antenna mounted amp? Any reccomendations as to make/model? I played with one a long, long time ago, from Radio Schlock, but it didn't last long.
I have always liked the Channel Master CM7777, but recent production is from China, and reported to be inferior to the older units. Check out the product reviews on Amazon:
http://www.amazon.com/Channel-Master...ter+tv+booster
At least one reviewer complained that he ordered from Amazon and got "old stock"... I would pay extra for the older version!

Not affiliated with Amazon or Channel Master,
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  #39  
Old 09-20-2012, 03:36 PM
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Originally Posted by jr_tech View Post
I have always liked the Channel Master CM7777, but recent production is from China, and reported to be inferior to the older units. Check out the product reviews on Amazon:
http://www.amazon.com/Channel-Master...ter+tv+booster
At least one reviewer complained that he ordered from Amazon and got "old stock"... I would pay extra for the older version!

Not affiliated with Amazon or Channel Master,
jr
I have used Blonder Tongue (), Winegard and Channel Master Mast-mount amps without much preference. One caution is to make sure you do not have a too-powerful FM transmitter nearby and/or on a multiple of the frequency you're trying to get. I used to have a problem with PBS channel 12 from Philly at my parent;s house, which was within sight (10 miles) of an FM (102.5 mc) station at 1/2 of channel 12's sound carrier. I could use only amps with tunable FM traps like CM 0064.
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  #40  
Old 09-28-2012, 03:18 PM
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JFD - Frankenstein of Antennas part 1 of 2

Last week, I climbed up into the darkness of the garage attic and pulled out a rather interesting UHF helical I snagged off a 3-story roof several years ago. JFD Zig-a-log.jpgI had attempted to get one of these several times only to be turned away by the queasy, litigation-shy and just plain ignorant to the $20 spot I offered. Breaking out WD40 for frozen wingnuts and emery cloth shined up harness connections for maximum conduction. I then climbed the tower and hoisted my Zig-a-log (LPV-ZU20) into place, connecting through the CM7777 mast amp, expecting some record-breaking performance. I was not disappointed. It was a tad less effective than the Jerrold, but had a significantly narrower beam. Again, nothing beats a parabolic CM4251 for UHF.

Update 10/1/12: During changeable rainy weather yesterday, the ZigaLog seemed to perform better on the "difficult channel WPPX" as the weather worsened. All the while the parabolic, located 40 feet away and at a lower elevation was having trouble holding the channel as is the norm during such weather.

Few antenna manufacturers of the glory days made their products as easy to identify as JFD. Originally JFD of Brooklyn NY seemed to make only signal splitters, couplers and other TV accessories. I have a few examples of those items and the boxes they came in. I have a few catalogs (out on loan) that covered much of JFD's late 1950s product line.
Here is an example of JFD's top-value UHF antennas that most manufacturers made, the 4-bay bow tie and corner reflector plus a mid-60s advertisement for JFD expressing frustration over a 1965 government mandate for all-channel TV stopping short of addressing antennas. Sound familiar? JFD Ad 2.pdf

This ad proclaims a breakthrough VHF design noting 6 patents which would be a formidable competitor for the next 15 years! Many of these are still visible on rooftops due to rugged construction.JFD Ad 1.pdf

This ad includes the "trapezoid" or helical design UHF antenna in a set-top version. My next post will feature a home-made replica of this little UHF wonder based on a 1970 JFD antenna I am still using. as a VHF performer. Hopefully, you can read the paragraphs supporting the "fight" against CATV coming to your area JFD Ad 3.pdf

J F D Antennas were usually so well-constructed, many can still be seen today. The tell-tale mid-element capacitors optimized high-band performance. They also had the most bizarre lookwith Channel Master coming in a distant second in that category.

The antenna pictured JFD LP VU.jpgis one of the last LPV models JFD made before becoming history. A search of JFD turns up little more than a patent infringement suit with Channel Master and a superfund site in NC.

Last edited by DavGoodlin; 11-02-2012 at 02:04 PM. Reason: Add ads and
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  #41  
Old 11-02-2012, 01:59 PM
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Cool Wacky JFD part 2

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 bandjfd 1.jpg.

This is a later version of a broadband VHF antenna jfd 2.jpg
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.
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  #42  
Old 01-01-2013, 05:00 PM
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Happy new year

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!
IMG_3363.JPG

Last edited by DavGoodlin; 01-02-2013 at 09:43 AM. Reason: miles correction
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  #43  
Old 04-18-2013, 01:24 PM
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Quote:
Originally Posted by DavGoodlin View Post
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
Yes.

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:
was also climbed more than once to replace a dead mast preamp!
Oh yes, in those days (the 70s), preamps were more failure prone (static discharge nearby lightning etc.), preamps still are failure-prone of course but some of them they are a bit better.

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.
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  #44  
Old 07-11-2014, 08:38 AM
Colly0410 Colly0410 is offline
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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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  #45  
Old 07-11-2014, 09:35 AM
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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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