I have a radio that I just bought used at an auction and it will only transmit when the Tx and Rx are the same. When I have it set up to go through the repeater and the Tx and Rx are different the radio will not transmit. Is this in programming or is it a bad radio? If its in the programming, how can I change it to transmit regardless if the Tx and Rx match??
Thanks in advance
Chris
GM300 will only transmit when RX and Tx same, no Tx on reptr
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chrisbern71
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chrisbern71
- Posts: 10
- Joined: Fri May 05, 2006 7:57 am
It sounds like the frequencies are within range of the radio.
Try some other transmit frequencies between 461 and 466 to see if it's just that particular frequency, or it dies somewhere lower. It's possible that the previous owner tweaked the radio to work elsewhere.
It's also possible that even though the radio is supposed to be that freq range, it could have had the RF board swapped so it's not 438-470 any more. To verify that, you'd need to open the radio and get the model number off the RF board; that will verify the band split.
If everything's legitimate and the radio transmits between 461 and 466 but not on your frequency, it should only take a simple adjustment to tweak it back to working again.
Bob M.
Try some other transmit frequencies between 461 and 466 to see if it's just that particular frequency, or it dies somewhere lower. It's possible that the previous owner tweaked the radio to work elsewhere.
It's also possible that even though the radio is supposed to be that freq range, it could have had the RF board swapped so it's not 438-470 any more. To verify that, you'd need to open the radio and get the model number off the RF board; that will verify the band split.
If everything's legitimate and the radio transmits between 461 and 466 but not on your frequency, it should only take a simple adjustment to tweak it back to working again.
Bob M.
A little more info on what happens when you attempt to TX on the repeater input would help.
Do you get a warning tone when you key the mic?
Does the TX LED light when you key the mic?
Have you verified with a wattmeter that there is no TX power out?
Is it possible the TX is actually working but you are just not keying the repeater due to a PL/DPL problem?
Do you get a warning tone when you key the mic?
Does the TX LED light when you key the mic?
Have you verified with a wattmeter that there is no TX power out?
Is it possible the TX is actually working but you are just not keying the repeater due to a PL/DPL problem?
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chrisbern71
- Posts: 10
- Joined: Fri May 05, 2006 7:57 am
GM300 Info
The red light does not come on. It does come on when the Rx and Tx are the same. There is no watts on the wattmeter when repeater freq. are used. I have another GM300 and it works fine on the repeater. So I know it has nothing to do with the repeater.
No warning tone either. I have verified the DPL's match.
Thanks
Chris
No warning tone either. I have verified the DPL's match.
Thanks
Chris
What you describe is certainly consistent with the synthesizer out of lock on those TX frequencies.
The problem would seem to be that the radio does not like the higher TX frequencies, not the fact that the TX and RX frequencies are different.
As kcbooboo suggested, try programming some lower TX frequencies and see how low you need to go to get it work. Then, it is a case of determining if it is a PLL tuning problem or the radio has the wrong RF board for that bandsplit. A more remote possibility is a control logic problem that does not like the higher frequencies.
If you confirm that it is the correct RF board, the next step would probably be to go through the "synthesizer out of lock" troubleshooting procedures in the service manual.
The problem would seem to be that the radio does not like the higher TX frequencies, not the fact that the TX and RX frequencies are different.
As kcbooboo suggested, try programming some lower TX frequencies and see how low you need to go to get it work. Then, it is a case of determining if it is a PLL tuning problem or the radio has the wrong RF board for that bandsplit. A more remote possibility is a control logic problem that does not like the higher frequencies.
If you confirm that it is the correct RF board, the next step would probably be to go through the "synthesizer out of lock" troubleshooting procedures in the service manual.