+5 the only duplex?

[WSBQ451]

I see that a certain repeater lists the rx and tx as 462.XXXX and 466.XXXX. Is this most likely a typo or is this possible? Thanks. Still learning! 

[SteveShannon]

6 minutes ago, WSBQ451 said:

I see that a certain repeater lists the rx and tx as 462.XXXX and 466.XXXX. Is this most likely a typo or is this possible? Thanks. Still learning! 

It’s either a typo or not GMRS. There are no 466 MHz frequencies in GMRS. 

[back4more70]

Yep, GMRS offset is always +5 to my knowledge.

[SteveShannon]

9 minutes ago, back4more70 said:

Yep, GMRS offset is always +5 to my knowledge.

It's programmed to be +5.000 MHz for the repeater channels on commercially sold GMRS radios, but the regulations don't actually require that.  They simply say that radios transmit to repeaters on the 467 MHz Main Channels and receive on the 462 MHz Main Channels.  Some repeater owners have chosen to deviate from the 5.000 MHz offset.  It's not technically non-compliant, but it effectively makes it very difficult for commonly available GMRS radios to be used.

I don't know why they do that, but I suspect a bias against inexpensive GMRS radios. So, they end up with inexpensive ham radios instead. 

[WSBQ451]

Hmm. I guess I'll try +5. If I don't receive any responses, then we know they are using +4. 

[Lscott]

1 hour ago, back4more70 said:

Yep, GMRS offset is always +5 to my knowledge.

That's the usual offset, however the rules don't require it. Note the FCC rules simply state what frequencies can be used for communications through a repeater, sections A and C, but don't mention a required offset.

https://www.ecfr.gov/current/title-47/chapter-I/subchapter-D/part-95/subpart-E/section-95.1763

Some have used a non-standard offset, still using the official frequencies, as a means to keep many users off a repeater since many radios "assume" a fixed 5MHz offset with no option for changing it. That leaves just those people with commercial grade radios that allow programming in separate TX and RX frequencies.

[MarkInTampa]

The strongest by far repeater in my area runs on 462.575 with the standard input of 467.575. It also has an alternate input on 467.725 with a dpl instead of ctcss tone on the same tower. It gets interference every now and then on the primary input from foreign ships in the port and the primary input gets shut down. The problem is some radios don't allow for anything other than a 5MHz split or split tones and it kinda locks them out until the primary input is turned back on.

 

[nokones]

4 hours ago, back4more70 said:

Yep, GMRS offset is always +5 to my knowledge.

All frequency pairs between 450 to   470 MHz are +5 MHz for mobile transmit to the repeater. All freq pairs above 470 MHz to 512 MHz are +3 MHz for mobile transmit to the repeater.