Thread: 2m tvi stub
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Old December 30th 08, 09:39 PM posted to rec.radio.amateur.antenna
JB[_3_] JB[_3_] is offline
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First recorded activity by RadioBanter: Apr 2008
Posts: 543
Default 2m tvi stub

154 MHz overloaded the antenna amp. I bought a "Midband Trap" from a TV
shop downtown which fixed things. It went inline and attenuated those
non-TV signals between (approx) 120 - 170 MHz. It was only a few

dollars
from one of the well-known TV reception equipment makers, Channel

Master,
I
think.

Unfortunately, I haven't found it from any familiar names, but I did
locate
this page http://www.microwavefilter.com/pdffiles/pg27.pdf. The
3367-A/I,
3367-B/G, 3367-C/G and 3367-C/H should all do what you need for 2m
suppression. Prices unknown.

... and this page: http://www.atvresearch.com/overstk.pdf Find their
number 5KMT-A/I-TX Midband Trap. A clearance sale bargain if they still
have any left.

Here's a single-frequency tunable notch;
http://www.microwavefilter.com/pdffiles/pg28.pdf.

Good luck.

These are pretty common in the CATV business where they will notch channels
to put their own access channel in place.

It is likely the CATV guy came out and took all the filters out in
preparation for the digital channel changeovers. There ought to be a High
pass filter to cuttoff below channel 2 and likely a notch for VHF
air/commercial?ham energy. They may have also goofed around with a cheap
distribution amp. Many of the good setups would split up and break out
individual channels to peak or attenuate to try to balance the lineup.