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Who controls the freq use on simplex 2 meters with these relay links

Jan 25th 2017, 22:36

kz4usa

Joined: Jul 4th 2010, 18:38
Total Topics: 0
Total Posts: 0
Here in Florida we seem to have some relay link system popping up all over the simplex freqs from 146.400 to 156.00 and who is controlling this? They don't seem to have a IDer etc. They just popup on the freqs and cause QRM for the people that use the simplex freqs.

What can be done about this.

Jack
kz4usa
Feb 3rd 2017, 13:38

WB1GCM

Joined: Apr 4th 1998, 00:00
Total Topics: 0
Total Posts: 0
You may be experiencing the effects of Third Order Intermodulation Distortion. That happens when two strong, evenly spaced signals are picked up on your antenna system and mix in the front end of your receiver. It can appear out of no where and sound like data, beeping, or as a voice transmission. Example, you are tuned to 146.520. Two strong signals are present at 151.520 and 156.520 MHz, which create a phantom signal at 146.520 MHz.

You can get rid of 3 IMD by using a transceiver that has a higher 3 IMD DR than the one you are currently using, or use an antenna with less gain.

As far as who controls the frequencies; they are usually coordinated by a volunteer frequency coordinator, but each licensed Radio Amateur has the right to transmit on frequencies for which he or she is licensed to, with the hope that they will use good judgement.

Bob Allison
WB1GCM
ARRL Lab

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