GR1225 troubleshooting assistance

[Dill]

I recently acquired a GR1225 (UHF high power version with duplexer). I've been able to get it programmed in the ham bands (444.725+), but it doesn't quite work right. When it turns on, it transmits a loud buzzing noise on the TX frequency, and has no RX. The duplexer has been tuned correctly (used it on another machine), and I checked the finals for desoldering (none found). I also unhooked the coax cable from the radio to the PA to see if it was the PA causing the buzzing, but it was not the PA. I've also totally removed the duplexer, hooking the TX direct to the dummy load with no change.

Here is a video I made for a friend of mine showing what it is doing. Does anybody have any suggestions, I'd really love to get this thing on the air. Thanks for any ideas!

https://www.youtube.com/watch?v=N-4o0F6on0g

[Dill]

I've also tried another power supply, same issues.

[d119]

VCO issue, without a doubt. Pull the boards out of the radio and inspect them for any leaky capacitors, damaged components, etc. I'd refer to this as more of a "motorboating" sound.

[Dill]

any idea why it would just start doing this? I got it to work for about 20 minutes, and noticed I forgot to program in my call sign. I went to bed and programmed my call in the next day, and it started doing this. Could it have somehow written the wrong radio service data as well?

[Dill]

I also inspected the radio, I don't see any leaky caps, burned traces, or any damage to speak of.

[jackhackett]

I notice in the video it shows generic signalling systems set for tx and rx, are you using some kind of signalling?

Also have you tried it on another frequency? Try one near the other end of the band and see what happens.

[Dill]

there was a generic one set in the programming when I received the radio. I tried it both ways, with and without, no difference. I did try it up at 462/467mhz with no change.

I'm trying to hunt down a known working CP to try. If anyone has one for this radio let me know, I'd like to try it to see if it makes any difference.

[d119]

I can't recall if Radius 1225 RSS allows you to create a "fresh" codeplug or not, but I'd try that. Are you trying to make the thing work out of band by chance?

[Dill]

no, I'm trying it on 444.725

I left it with another ham tonight who is going to try to clone his working 1225 onto mine to see if that works. I will keep everyone posted on what happens.

[Dill]

I was told that the radio was basically faulty. I received a refund and purchased a different radio, which works fine. Thank you for all the tips and hints, this certainly has been a good learning experience.