It's a real shame that Channel Master decided to redesign the 4228.
Nothing was wrong with the old design and it's better than the new
one. They absolutely ruined what was a good antenna. About the only
antennas I would give up my pair of 4228As for are a pair of the
Antennas Direct 91XG yagi/corner reflector or the CM4251 "parascope"
parabolic UHF dish, and probably a pair of those too, if they were
still made!
Ken Nist KQ6QV has a website (www.hdtvprimer.com) that compares the
new and old antennas. The new one is definitely a step back and not a
step forward.
My 4228A array consists of two of them one over the other phased
together with 2ft each 75 ohm phasing lines connected to an ordinary
75 ohm splitter for a total of 16 bays. I have been considering
changing that to a 300 ohm combiner and using 300 ohm phasing lines to
eliminate the loss in the baluns.
As for why you will get VHF on the CM4228A it is because of the
reflective screen. The reflector acts as the primary radiating
element on high VHF. This is why I had to opt for a separate VHF
antenna. Since I have two of the 4228A antennas phased together, my
antenna no longer works on high VHF. In the NYC market we have 7, 11
and 13 on high VHF so I need a high VHF antenna. So I opted for the
winegard YA1713 and a VHF/UHF combiner which allows me to combine both
UHF and VHF with just a small 0.5dB insertion loss instead of 3.5dB if
I had used an ordinary splitter.
I must say it works quite well, and having the antennas on a tower
instead of the roof helps me pull in everything. If I aim the UHF
antennas towards Philly I can get most of their stations as well.
73
Ryan, N2RJ
On Wed, Apr 28, 2010 at 11:28 AM, Jim Brown <jim@audiosystemsgroup.com> wrote:
> On Tue, 27 Apr 2010 19:49:46 -0400, Ryan Jairam wrote:
>
>>I operate at around 800 watts and there's no interference on my TVs.
>
>>This is my TV antenna setup -
>
>>2 x Channel Master 4228 (16 bay bow tie array, with a reflective screen)
>>for UHF
>>Winegard YA1713 Yagi for VHF 7-13
>>Antennacraft 10G212 30dB preamp
>
> I have the same result from a similar setup -- one of those 4228 antennas
> (8 bow ties in a 4x2 array) on a 20 ft mast just outside my shack feeding
> a Zenith DTV converter to a Channel Master preamp feeding a late 90s
> vintage Panasonic analog TV. No TVI, even from 1.5kW into the 160M
> vertical, only 20 ft away! The only "filtering" is in the form of coaxial
> ferrite chokes on all the antenna cables, including the coax coming from
> the 4228. My "local" channels are all more than 40 miles away, and two
> are high-band VHF (8 and 13). Most interesting is that the VHF signals
> are the most solid (less breakup from fading) than the UHF signals, even
> though it's a UHF antenna!
>
> If you install anything and run into trouble, the first thing to do is
> add one or more ferrite chokes just ahead of the first RF stage tuned to
> the ham frequencies that cause interference.
>
> 73,
>
> Jim K9YC
>
>
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--
Ryan A. Jairam,
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