I’ve been licensed on GMRS for roughly 15 years and on other bands for many years before that.
In early September, 2022, I was accessing a GMRS repeater in Southern California that has been licensed and operational for over 30 years. Each time I keyed our repeater, there was a heterodyne on the output that blocked our communications.
It took a while to diagnose the problem. With the help of other repeater users, we determined that a new repeater had recently gone on the air. But, unlike every other repeater on this shared frequency, this new one was not following the industry best practice of filtering and protecting its own input receiver with a CTCSS (PL) tone.
That meant that when anyone tried to use any local repeater on that frequency pair, this new repeater intercepted their PL-encoded input signals (against the sender’s intentions) and broadcast their messages over its own output transmitter, thus misdirecting messages intended for other repeaters. This created an unwanted heterodyne between two repeaters that degraded everyone’s communications.
Then, this new repeater owner accused us of jamming their repeater, which is an odd form of reverse logic. They were jamming their own repeater by not implementing a selective PL tone filter on their own receiver. They were effectively sabotaging themselves and blaming everyone else.
We’ll keep the name of that new GMRS club and repeater owner private and confidential. It seems that these are very nice young people with good intentions to provide communications capabilities to the general public.
We totally support their mission. We think everybody should have the opportunity to use GMRS for personal communications and emergency preparedness. We’ve tried to become their friends by reaching out to them, but they have ignored our offers of technical assistance and refuse to even communicate with us to resolve this.
All we are asking is that these new people respect the fact that there are legacy repeaters that have been on the same frequency for 30 years or more. We are merely requesting that they comply with Part 95 guidelines to share the frequency in a way that does not inhibit other users from continuing their ongoing use of older legacy repeaters.
There could be several different technical solutions here. One of which is to adopt the common standard practice of implementing a selective PL tone filter on their repeater receiver, so that they do not intercept and re-transmit traffic that is intended for other repeaters — not intended for their repeater.
Does this seem like a fair and reasonable request?
We can all be friends and share these frequencies if we simply configure our repeaters correctly using common industry standards. When emergency communications are needed, we all need to be ready to operate efficiently and cooperatively.
And we all should work professionally with mutual respect as colleagues and friends at all times.
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