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Old 09-07-2012, 08:59 AM
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DavGoodlin DavGoodlin is offline
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Join Date: Aug 2011
Location: near Strasburg PA
Posts: 3,400
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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