Two VX-3000Us, RX fine but 'burp' and cut out on TX
Posted: Mon Aug 18, 2008 2:37 pm
A few months ago, I bought a couple of VX-3000U's from a large lot on eBay. At the time, I tested them for RX/TX, then put them away until I would have time to play with them.
Now I am finding that receive and tone decode is fine, but they do not transmit, though I remember they did earlier. When I key up, the speaker makes a little 'burping' sound. RF output on the wattmeter is around 1 watt, and the needle shakes in little spurts. I don't have access to a service monitor, but there is no modulation on frequency that can be picked up with another radio.
At one point, on the low-power (5W) setting I had it putting out maybe 2 watts with audio for just a second, then it would drop out. The way it drops out and burps reminds me a lot of a handheld with a battery going dead. However, with a 13.2 VDC power supply connected, the voltage across the leads never drops below 12.9 VDC while the radio is keyed. I can't smell any smoke anywhere, and nothing seems to be getting "hot."
Both radios do this. I swapped out their mikes, and switched their cords end-to-end, and tried each on different power supplies. If I power up the radio with the "monitor" button pressed, there is a beep and if I key up right then, it puts out about 25 Watts for about 1 second. Then there are four beeps and there is no more RF output. I have no idea what power-up with monitor engaged is supposed to do; I'm just grabbing at straws here since I have no programming manual.
The code plugs seem to upload and download just fine using the CE19 software under MS-DOS 5 environment on a 486 machine, plenty slow at 25 MHz. If I had one radio, I'd straight out assume I just have a lemon - bad power supply, or maybe a bad mic. But two radios from the same lot?
The only other thing these radios have in common is that they both were programmed by the seller before shipping. I played with the software, eliminating the Time-Out Timer and reducing the penalty timer from 50s to 5s, but no change.
Can anyone say this resembles a symptom that's been seen on this kind of radio? Or, can you tell me if there are any programming "tricks" and "traps" that must be remembered when programming these radios? I have no sample default programming file to compare with my radios.
Thanks for your attention and your suggestions,
-T.
Now I am finding that receive and tone decode is fine, but they do not transmit, though I remember they did earlier. When I key up, the speaker makes a little 'burping' sound. RF output on the wattmeter is around 1 watt, and the needle shakes in little spurts. I don't have access to a service monitor, but there is no modulation on frequency that can be picked up with another radio.
At one point, on the low-power (5W) setting I had it putting out maybe 2 watts with audio for just a second, then it would drop out. The way it drops out and burps reminds me a lot of a handheld with a battery going dead. However, with a 13.2 VDC power supply connected, the voltage across the leads never drops below 12.9 VDC while the radio is keyed. I can't smell any smoke anywhere, and nothing seems to be getting "hot."
Both radios do this. I swapped out their mikes, and switched their cords end-to-end, and tried each on different power supplies. If I power up the radio with the "monitor" button pressed, there is a beep and if I key up right then, it puts out about 25 Watts for about 1 second. Then there are four beeps and there is no more RF output. I have no idea what power-up with monitor engaged is supposed to do; I'm just grabbing at straws here since I have no programming manual.
The code plugs seem to upload and download just fine using the CE19 software under MS-DOS 5 environment on a 486 machine, plenty slow at 25 MHz. If I had one radio, I'd straight out assume I just have a lemon - bad power supply, or maybe a bad mic. But two radios from the same lot?
The only other thing these radios have in common is that they both were programmed by the seller before shipping. I played with the software, eliminating the Time-Out Timer and reducing the penalty timer from 50s to 5s, but no change.
Can anyone say this resembles a symptom that's been seen on this kind of radio? Or, can you tell me if there are any programming "tricks" and "traps" that must be remembered when programming these radios? I have no sample default programming file to compare with my radios.
Thanks for your attention and your suggestions,
-T.