coopthink

As a follow up, I picked up another meter on Amazon overnight (Surecom SW-102S) and found that it reads ~5.31 watts into a dummy load, which is acceptable. I think that my MFJ-849 has a problem; although it seems pretty accurate at higher wattages. I think that the repeater is fine and that I need to send back the MFJ meter, if possible.

Thanks for the quote/reply! Yeah, I double checked the programming and strangely, I get the same ~3.7 watts on high and low power. The same thing happened on my RT97. I only have one meter, the MFJ-849, but it seems pretty accurate on all the other radios I've tested. Even the 3.7 watts is good for my camping, kayaking, skiing and other outdoor mobile uses, so it will work, but it's just strange that I'm getting such low power. I mean, close to 5 watts after the duplexer, I could understand, but no idea. I might pick up another meter and see what I get.

I just got the MXR10 today and have also commented on Notarubicon's excellent YouTube video. I'm only getting ~3.7 watts into a dummy load across all repeater channels, which is similar to the RT97 that I used to have. I got rid of the RT97 due to the low power, but I missed it due to the portability. I'll hang on to the MXR10, but would be interested in more real world power measurements from other users.

I thought I would add to this thread that I went back and tested with a dummy load and it seems that I am getting 3.4-3.5 watts on both low and high settings, which is strange. I have reached out to Retevis and while they were quick to respond, I haven't gotten any useful info yet. I've seen folks actually getting 5 watts out from the RT97, so I think this unit definitely has a problem. I'll update the thread with anything I get back from Retevis.

I didn't test low power; although I might do that tomorrow, but I recently bought a used RT-97 tuned for GMRS (462.550/467.550) and I got around 3.5 watts using the base antenna that came with the repeater. I didn't test with a dummy load because I didn't think I could key up the repeater. It's hard to find specs on the antenna that came with the repeater, but this is the package that I bought gently used on Ebay: https://www.retevis.com/rt97-portable-gmrs-repeater-mobile-repeater#A9150CX1-C9196AX1-C9123AX1 So far, for my needs, the RT-97 works just fine and on a recent ski trip, I ran it in my vehicle with a mag mount antenna and was able to talk all over the mountain. Also, I tested the antenna with my NanoVNA and have attached the SWR graph, which is not bad at all.

Glad you got it working!

It looks as though the software can't see COM5. I would try restarting the software in case you plugged in the cable after it started. It could also be the USB serial driver for Windows 11. It works fine with Windows 10, but you might try installing the latest driver from FTDI in case the native driver isn't working. Here's the website and the direct link for the driver.

I found a link to the RT97S USB driver on this page. I have the RT97 and didn't need the driver with Windows 10, but it seems to be the relatively common Prolific chipset.

After reading through this thread, it sounds as though you're trying to use the USB-C charging cable that comes with the GM30. That cable can only be use for charging. For programming, you'll need a USB cable that connect to the audio connectors on the side. I use the cable below with the GM30 and lots of other radios. It will create a new virtual com port that you can see in Device Manager. I don't think I needed any additional drivers for Windows 10 and it works on my Mac as well. BTECH PC03 FTDI Genuine USB Programming Cable for BTECH, BaoFeng UV-5R BF-F8HP UV-82HP BF-888S, and Kenwood Radios