Jump to content

GMRS: The New Business Radio Service


intermod

Recommended Posts

I have been involved with GMRS for almost 30 years and have never seen such an abrupt increase in business radio use of the 462 MHz primary channels until the last two years.  It has accelerated over the past year to the point where many of us can no longer communicate with more distant repeaters from my base station between 6 AM and about 8 PM, M-F due to co-channel radio traffic.  Weekends are increasingly becoming a problem as well. 

 

I have also seen an increase in adjacent-channel interference from the 12.5 kHz interstitial channels on the base station, primarily because a large number of these commercial users have FRS radios improperly programmed for wideband (25 kHz) operation. 

 

I am located in the suburbs east of San Francisco/Oakland, with 2200' mountains between me and the busy bay region.   I can only imagine what the bayside users are experiencing.  

 

Anyone else seeing this problem? 

 

Link to comment
Share on other sites

I have been involved with GMRS for almost 30 years and have never seen such an abrupt increase in business radio use of the 462 MHz primary channels until the last two years.  It has accelerated over the past year to the point where many of us can no longer communicate with more distant repeaters from my base station between 6 AM and about 8 PM, M-F due to co-channel radio traffic.  Weekends are increasingly becoming a problem as well. 

 

I have also seen an increase in adjacent-channel interference from the 12.5 kHz interstitial channels on the base station, primarily because a large number of these commercial users have FRS radios improperly programmed for wideband (25 kHz) operation. 

 

I am located in the suburbs east of San Francisco/Oakland, with 2200' mountains between me and the busy bay region.   I can only imagine what the bayside users are experiencing.  

 

Anyone else seeing this problem? 

True FRS radios certified by the FCC are designed for a fixed bandwidth of 12.5 KHz on all channels. Also the power is limited to no more than 2 watts on channels 1-7 and 15-22. Channels 8-14, the interstitial ones, are limited to 0.5 watts max.

 

So if you’re sure the bandwidth is too wide on 8-14 and maybe too high of power those users likely are not using FCC  certified radios. They could be miss programmed Part 90 or Ham radios, CCR’s, being used. If that’s the case it’s a whole other issue.

Link to comment
Share on other sites

  • 2 weeks later...

I have also seen an increase in adjacent-channel interference from the 12.5 kHz interstitial channels on the base station, primarily because a large number of these commercial users have FRS radios improperly programmed for wideband (25 kHz) operation. 

 

I am located in the suburbs east of San Francisco/Oakland, with 2200' mountains between me and the busy bay region.   I can only imagine what the bayside users are experiencing.  

 

Anyone else seeing this problem? 

 

FRS is narrowband only (11k2f3e).  Commercial users can't be using FRS radios if they can be programmed for wideband (16k0f3e or 20k0f3e) operation.  Just sayin'.

 

I have experienced adjacent channel splatter from the 12.5kHz interstitials on the GMRS primary channels.  It's happened when I'm listening to a GMRS primary channel (wideband) and kids in my neighborhood are playing around with FRS bubble packs on an FRS channel 12.5kHz away from the GMRS primary channel I'm listening to.  I was experiencing adjacent channel splatter even though the FRS users were operating narrow band with legal FRS radios.

 

I have also had one of my GMRS repeaters which was operating wideband at the time get hit by FRS traffic on the 467MHz FRS channels adjacent to the repeater input.  The FRS users were local to the repeater and on a 467MHz FRS channel 12.5kHz away from the repeater input.  The CTCSS tone they were using happened to match one of the CTCSS tones in the repeater.  The repeater would get keyed up and scraps of badly distorted audio would be heard through the repeater.   I've witnessed the same thing happening to GMRS repeaters in other areas of the country in my travels and have even heard GMRS users on the repeater yelling at the FRS users to stop and of course the FRS users won't hear them LOL.

 

Since I'm using good quality Part 90 commercial gear, I went with the flow of Part 90 narrowbanding and switched all of my commercial radios and the repeater to narrow (11k2f3e) mode on all GMRS channels.  Narrowing the transmit deviation and tightening up the receiver solved all of my adjacent channel splatter from the interstitials and also solved it in the repeater.  All of my adjacent channel splatter problems went away completely as soon as I made the switch to narrow mode on all GMRS channels.

Link to comment
Share on other sites

I have been involved with GMRS for almost 30 years and have never seen such an abrupt increase in business radio use of the 462 MHz primary channels until the last two years.  It has accelerated over the past year to the point where many of us can no longer communicate with more distant repeaters from my base station between 6 AM and about 8 PM, M-F due to co-channel radio traffic.  Weekends are increasingly becoming a problem as well. 

 

 

I too have noticed an uptick of business use over the past couple of years since the rewrite of the Part 95 rules in 2017.  I'm not complaining since business use of FRS is 100% legal.  We have to coexist as best we can.  Going with the flow of Part 90 by narrowbanding my commercial gear on GMRS solved all of my adjacent channel splatter problems.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use and Guidelines.