PugetSounder

I have the same GM-15 radios. The Radioddity software I used is GM30 v1.05 from their website. Works perfectly on my radios. I've added police and fire on DIY channels w/no issues. I bought the BTECH cable with the FTDI chip and Windows 10 recognized it without having to load any additional drivers. Some users have reported issues after using the GM30 firmware update on the GM-15 Pro so I took their advice and didn't use it. BTW. Get the GM 30 manual while you're there. It's well written and fully compatible with your GM-15.

Thanks for that excellent reply. I'm just a humble hobbyist and trying to get my head wrapped around all this.

Clipped from an ARES 2m Net instruction page: The repeater is linked into the (Name Removed ) network of repeaters during the net, so remember to pause for a full second or two before talking when transmitting to allow for all of the repeaters in the network to sync up. Given the nature of many GMRS users, I would expect a total mess so be careful of what you wish for. Also, network of repeaters seems to be the appropriate term in this context. Glad the FCC doesn't allow it. (My bold)

People need to think about the delay that exists in linking repeaters. The more repeaters, the bigger the delay. This is not a problem with trained hams that meet and discuss operational procedures. They are trained on what to expect. Now get a bunch of newbies with a fresh GMRS license and a $25 radio and you will hear a ton of partial transmissions, people stepping on each other and requests to try again. I spent 8 years in NATO (Germany and Italy) and just making a simple phone call across the Atlantic was an issue because of the delay. Even though we knew that there was a delay, it was still difficult to time your words without stepping on each other.

I don't know either, but I was just speculating that the radio briskly polling between the two would result in a bit larger draw as opposed to just monitoring a single channel.

That makes sense. So I've been dual watching (scanning) two different channels on the same frequency and it's just burning battery faster without any appreciable benefit.

I should also add that I can hear the repeater with my Cobra FRS radios for short periods. TSQL is also heard. Not routinely though. I'm assuming because of changes in propagation.

Thank you Steve. You got me thinking... Maybe I should listen for the TSQL to be sure. Sure enough, I'm hearing TSQL on both channels (018 and 026). But the arrow will change at times. This led me to believe that the radio was able to distinguish between simplex and duplex. Now I'm not confident. Does anybody have an explanation for this or am I missing something?

"Would lowering the squelch on the HT and the Repeater help with this issue at all, even if only in a small way?" Absolutely. Lower the squelch until you get constant static. Then move the setting up a bit until it quiets. If you get occasional noise without readable traffic, move it up another notch. You're looking for the lowest squelch setting without annoying noise. Having squelch at lower settings helps to receive weaker signals that higher squelch settings will ignore. Do one at a time though. I would start with my HTs on simplex.

That last sentence probably didn't make much sense. So let's try again. Male voice is WWV Ft. Collins, Colorado Female voice is WWVH Kauai, Hawaii. Different calls signs. But still a good propagation day if I can get them both.

I used 198.309.441 per the guidance in Sshannon's link. There's a solid pilot there that is easy to zero. Tech tip #1 - Calibrating your SDR / Finding a suitable frequency source <snip> When calibrating a unit, use as high a frequency as you can. The higher the frequency, the more accurate the unit will be over the entire reception range. Errors will multiply as the frequency multiplies. Conversely, errors will divide as the frequency is divided. A 4 Hz error at 200 MHz will be 8 Hz at 400 and 16 Hz at 800 MHz. but if you calibrate to within 4Hz at 800 MHz, that will translate to a 2 Hz error at 400 MHz and 1 Hz error at 200 MHz. A GPS Disiplined Oscillator is the preferred common source. If you do not have access to one, an ATSC DTV transmitter pilot carrier is a good over-the-air alternative. These can be found at 309.440559 kHz above the lower channel edge. For example, if the DTV station transmits on Channel 11 (198-204 MHz) this pilot can be found at 198.309440559 MHz. Obviously the Airspy will not resolve to MilliHertz, so use 198.309441 MHz. That will still be accurate within 1 Hz. But I do like to use WWV @ 5, 10, 15 etc to find open bands. On a good day I can hear both the male and female voices indicating a strong signal from both Hawaii and Colorado.

And here's my apology to NOAA (if you are out there)

Turns out that my setting is -2. Mystery solved!

Man that is a great find! And this a helpful group. Thank you all.

Thank you! This seems to be what I've been missing. -Easy enough too.