"ml" wrote in message
...
after my building changed to a new tv antenna and master amp
seems i am giving alot of tvi on strangly enough 2m

also some tvi from 10m too never did before

my antenna is physically pretty close to the antenna (thou it also
was previsiously )

for an experiment i was thinking about just making a coaxial stub
for 2m to see if that would 'notch ' out the interference

and using a T connector putting it just before the master amp (which
i think is just amplifing my 2m signal and mixing w/the tv channels
and or overloading the tv's)


should the stub be 1/4w on 2m or would say 1/2w be 'better'?

i'd cut it for the center of 2m


tnx

Open quarter wave, shorted half wave. I don't know which is better.
Remember to shorten the stub length by the velocity factor of the coax.

I had a similar problem years ago on a Navy ship. Nearby taxi radios around
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.