How do you determine offset?

[WRXK360]

Another new-guy question. I can't find a straightforward answer of how to translate the repeater values in MyGMRS to determine what the offset should be. I'm not hearing anybody on the repeaters near me which are all near a major interstate.

[back4more70]

GMRS repeater offsets are +5 MHz.  For example, transmit on 467.55 and receive on 462.55.

[WRXK360]

Thank  you. Can you recommend any resources to learn more about Amateur radio, specifically GMRS?

[marcspaz]

26 minutes ago, WRXK360 said:

Thank  you. Can you recommend any resources to learn more about Amateur radio, specifically GMRS?

In Amateur Radio and GMRS the offset is always up (+) 5 megahertz. So, if the receive frequency is 444.xxx, the offset is 449.xxx. or, if the receive frequency is 462.xxx, the offset is 467.xxx.

Amateur Radio and GMRS are 2 distinctly different services. Do you want to learn about Amateur Radio, GMRS, both or radio communications technology in general? 

[WRUU653]

19 minutes ago, WRXK360 said:

Thank  you. Can you recommend any resources to learn more about Amateur radio, specifically GMRS?

This forum. FYI most GMRS radios (at least the ones I have) come with the offset already programmed in the predefined repeater channels. 

[back4more70]

31 minutes ago, WRXK360 said:

Thank  you. Can you recommend any resources to learn more about Amateur radio, specifically GMRS?

I learned a lot about GMRS via YouTube, specifically from the Queen himself NotaRubicon Productions.  For amateur radio, I read through the ARRL Technician study guide/manual/whatever it's called.

[back4more70]

14 minutes ago, marcspaz said:

In Amateur Radio and GMRS the offset is always up (+) 5 megahertz.

I agree with the GMRS statement, but I see lots of 70cm repeaters in California in which the offset is positive or negative (but always 5MHz).

[marcspaz]

2 minutes ago, back4more70 said:

I agree with the GMRS statement, but I see lots of 70cm repeaters in California in which the offset is positive or negative (but always 5MHz).

 

 

You are correct. My mistake. It's always a 5 MHz split... only 'always' +5 in GMRS.  Thanks for the catch!

[Sshannon]

1 hour ago, WRXK360 said:

Another new-guy question. I can't find a straightforward answer of how to translate the repeater values in MyGMRS to determine what the offset should be. I'm not hearing anybody on the repeaters near me which are all near a major interstate.

One nice thing about GMRS is that radios which are certified for use for GMRS come preprogrammed with the correct channels.  All you have to do is choose one of the repeater channels and set the tone to access the repeater. So, for most GMRS radios, channels 1-22 are not for use with repeaters, but rather for direct communications using a single frequency, which is known as Simplex communications.

The repeaters reuse channels 15-22 for receiving, but add eight more frequencies, which are almost always exactly 5 MHz higher than the receive frequencies.  That’s done usually without you needing to know much about how it works.  

The repeater channels will often be called something that implies that relationship.  So, for instance, 15RP would be the “channel” that you set your radio to which receives on the same frequency as 15, but transmits on a frequency that is 5 MHz higher. The frequency offset is necessary for a repeater to transmit at the same time it receives, which is called Full Duplex.   Channel 15 for example is 462.550 MHz.  Channel 15RP receives on 462.550 MHz, but automatically transmits on 467.550 MHz. You should not be entering frequencies for transmitting and if you have a radio that’s certified for GMRS you don’t have to. 

Sometime the company doesn’t call the repeater channels 15RP through 22RP.  Sometimes they number them 23-30, but it means the same thing.

I echo the others who recommended watching Notarubicon videosas a way to get started in GMRS.

As Marc pointed out GMRS and Amateur Radio are two completely different service.  In GMRS you simply buy a license and radio and begin using it.  GMRS is primarily about using the radio for short range personal communications. Amateur Radio encompasses that and much more.

 

 

[marcspaz]

2 hours ago, WRXE944 said:

In Amateur Radio, the amount of the offset depends upon the specific band

 

I assumed we're talking about UHF in and around 400-500 mhz. Hence my answer/examples.

 

That said, you're correct and I'm sure the information will be helpful. 

[Sshannon]

1 hour ago, marcspaz said:

 

I assumed we're talking about UHF in and around 400-500 mhz. Hence my answer/examples.

 

That said, you're correct and I'm sure the information will be helpful. 

It was very clear what you meant from the context of the conversation.

[DIHOWARD61]

A repeater owner gives a frequency and a DCTS tone. Is that frequency the Tx or the Rx.

Tx is +5.0 mhz ?
.

[axorlov]

1 hour ago, DIHOWARD61 said:

A repeater owner gives a frequency and a DCTS tone. Is that frequency the Tx or the Rx.

Tx is +5.0 mhz ?
.

Repeater owner publishes repeater output frequency, it is your Rx. On GMRS it is always in 462.xxx MHz range. Repeater input is +5 MHz, it is your Tx, and it is always in 467.xxx MHz range.

[Sshannon]

10 hours ago, DIHOWARD61 said:

A repeater owner gives a frequency and a DCTS tone. Is that frequency the Tx or the Rx.

Tx is +5.0 mhz ?
.

That frequency is the one you listen to.

Yes, TX is up 5 MHz and that’s where you must use the DCTS tone to get into the repeater.  If your radio is a certified gmrs radio the offset will already be included when you choose a repeater channel (15RP - 22RP or 23-30 depending on how your radio has them labeled.) 

I recommend leaving the tone off of your receiver at first, so you can be sure you get in.  If you’re bothered by hearing other non-repeater traffic on the frequency you can always add DCTS to your receive channel.

[BoxCar]

I use the mantra High In, Low Out when dealing with repeaters.

[nokones]

8 hours ago, BoxCar said:

I use the mantra High In, Low Out when dealing with repeaters.

Or High up (link) and Low down (link).

[WRUU653]

14 hours ago, BoxCar said:

I use the mantra High In, Low Out when dealing with repeaters.

Is that what YES meant when they sang “shoot high, aim low”?