Programming Basics - "VFO A" and "VFO B"

[Sbsyncro]

I'm just starting to dive into programming the various radios I have (Baofeng, Radioddity, Wouxun, Midland, etc) and one thing I am confused about is that all seem to have some confusing choices around "VFO A" and VFO B".   Are these just the currently displayed A and B channels on the radio's display?  (and they actually just correspond to one of the existing programmed channel "slots"?).   What is confusing me a bit is that my Radioddity GM-30 is set for a single line display and the currently tuned channel is 17 (462.6000) but that is not what either the VFO A or VFO B slot is programmed for.....   

[WyoJoe]

VFO typically refers to the mode of tuning the radio to a particular frequency manually. On many radios, you can use either Frequency (VFO) mode or channel mode. You can switch modes by pressing and holding the "menu" button for 3 seconds.

In the GM-30 software, I believe VFO A and VFO B refer to the default frequencies that the radio will tune if you select Frequency mode. The channel tuning is configured separately from the VFO A and B frequencies.

I believe your radio is in "Sync" mode since you stated it's set for a single line display. In that configuration, it will only show one VFO (tuner) at a time (in Frequency mode), although the radio has a dual watch or dual scan function when not in Sync mode. VFO A is tuner #1 and VFO B is tuner #2. You can switch between them by pressing the "exit" button on the radio.

[Sbsyncro]

Thank you. So the VFO A and VFO B slots are what will be displayed/active if the radio is changed to VFO mode then? I’m trying to figure out a good use case for that feature…

I do notice that it is the only place once can specify non-GMRS frequencies for Rx only.


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[WyoJoe]

If you are programming the radio with a computer, you can add non-GMRS UHF or VHF receive only frequencies in the empty channels slots.

That way, you can scan or tune to those channels if you want.

[Sbsyncro]

If you are programming the radio with a computer, you can add non-GMRS UHF or VHF receive only frequencies in the empty channels slots.
That way, you can scan or tune to those channels if you want.

I don’t see how. The channel editing window only allows a drop down of GMRS frequencies to choose from except for the 2 VFO slots, which have an editable field for frequency. Note that I am running v 2.6 of the software and the latest firmware for the radios.


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[SteveShannon]

44 minutes ago, Sbsyncro said:

I don’t see how. The channel editing window only allows a drop down of GMRS frequencies to choose from except for the 2 VFO slots, which have an editable field for frequency. Note that I am running v 2.6 of the software and the latest firmware for the radios.


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Can Chirp can be used for your radio? It allows free-form entry for the radios I’ve used it with.

[Sbsyncro]

34 minutes ago, Sshannon said:

Can Chirp can be used for your radio? It allows free-form entry for the radios I’ve used it with.

Unfortunately it doesn't look like it.

 

[MichaelLAX]

Most GMRS radios disable their VFO ability, so as to keep within FCC regulations for GMRS.

Which models besides the GM-30 do you have?

[WyoJoe]

16 hours ago, Sbsyncro said:

I don’t see how. The channel editing window only allows a drop down of GMRS frequencies to choose from except for the 2 VFO slots, which have an editable field for frequency. Note that I am running v 2.6 of the software and the latest firmware for the radios.


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On mine, with the computer software, I just click on the frequency field of a blank channel, and type in the frequency. I've done this to add a local ham repeater that I sometimes monitor.

The only channels where you get the "pick list" you describe is on the DIY channels up to channel 54. Try entering your new frequency on a channel higher than that.

The DIY channels allow you to program your radio for additional repeaters on the same frequencies, but with different CTCSS tones/DCS codes. That way, you can just switch channels to switch between them rather than having to edit the tone or code for the channel you're on.

Above channel 54, the frequency field is a free-form field, so you can enter any value within the receive range of the radio. These channels are set for receive only, but cover a moderate amount of the UHF/VHF spectrum.

[WyoJoe]

15 hours ago, Sshannon said:

Can Chirp can be used for your radio? It allows free-form entry for the radios I’ve used it with.

Chirp does not work (yet) with the GM-30 or any of its clones. Fortunately, the factory software is tolerable, for me at least.

[Sbsyncro]

11 hours ago, WyoJoe said:

On mine, with the computer software, I just click on the frequency field of a blank channel, and type in the frequency. I've done this to add a local ham repeater that I sometimes monitor.

The only channels where you get the "pick list" you describe is on the DIY channels up to channel 54. Try entering your new frequency on a channel higher than that.

The DIY channels allow you to program your radio for additional repeaters on the same frequencies, but with different CTCSS tones/DCS codes. That way, you can just switch channels to switch between them rather than having to edit the tone or code for the channel you're on.

Above channel 54, the frequency field is a free-form field, so you can enter any value within the receive range of the radio. These channels are set for receive only, but cover a moderate amount of the UHF/VHF spectrum.

Sorry, I was browsing this too fast on my phone and just realized that my previous post talked about Rx-only programming, and thats where I led myself astray.    What I meant to mention is that  there is no ability to specify a TRANSMIT frequency.  If you use the "DIY" slots, then the TRANSMIT frequency is hard coded to a 5 MHZ offset (for GMRS repeaters). 

If you use one of the "empty" slots at the bottom, then it is a RECEIVE ONLY channel, as there is no way to specify a Transmit frequency:
 

[WyoJoe]

10 hours ago, Sbsyncro said:

Sorry, I was browsing this too fast on my phone and just realized that my previous post talked about Rx-only programming, and thats where I led myself astray.    What I meant to mention is that  there is no ability to specify a TRANSMIT frequency.  If you use the "DIY" slots, then the TRANSMIT frequency is hard coded to a 5 MHZ offset (for GMRS repeaters).

If you use one of the "empty" slots at the bottom, then it is a RECEIVE ONLY channel, as there is no way to specify a Transmit frequency:

On those points, to the best of my knowledge, you are correct. I think I even tried once to enter simplex programming on one of the DIY channels and was denied. I could only program GMRS repeater frequencies into the DIY channels. As you noted, it won't let you enter anything outside of that range.

[Sbsyncro]

Just got this message back from their support person:

The current DIY channels are repeater channels, we will open 1-22CH frequencies to choose in the future. The software is still testing by our engineer. Please stay tuned.


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