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Post by capn357 on May 27, 2017 22:45:51 GMT -5
I have a Motorola CB 555 that is exhibiting a weird (to me) problem on transmit. Here's the deal. If you power the radio on and key the mike, it will initially transmit at extremely low power (like 54 dB below where it should be). However, if I keep keying and unkeying the mike, the transmit power will eventually work it's way up (not all at once) finally topping out at a good solid 4 watt carrier. Once it reaches the 4 watt output, it will continue to reliably output at 4 watts on subsequent mike keys for as long as I've had the patience to sit there and run through the process. However, if I stop keying the mike and just leave the radio on for a while (say 30 minutes) and then come back to it and key the mike, I'm back at the extremely low power output mode. Just like before, if I continue to key and unkey the mike, it will eventually work it's way up to the 4 watt output and is steady at that point so long as I'm periodically keying the mike (like you would be if you were having a real conversation).
Has anyone ever heard of any radio behaving this way? Any thoughts on what would cause such behavior?
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Sandbagger
Administrator/The Boss 
Posts: 6,247 
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Post by Sandbagger on May 28, 2017 18:30:56 GMT -5
I have a Motorola CB 555 that is exhibiting a weird (to me) problem on transmit. Here's the deal. If you power the radio on and key the mike, it will initially transmit at extremely low power (like 54 dB below where it should be). However, if I keep keying and unkeying the mike, the transmit power will eventually work it's way up (not all at once) finally topping out at a good solid 4 watt carrier. Once it reaches the 4 watt output, it will continue to reliably output at 4 watts on subsequent mike keys for as long as I've had the patience to sit there and run through the process. However, if I stop keying the mike and just leave the radio on for a while (say 30 minutes) and then come back to it and key the mike, I'm back at the extremely low power output mode. Just like before, if I continue to key and unkey the mike, it will eventually work it's way up to the 4 watt output and is steady at that point so long as I'm periodically keying the mike (like you would be if you were having a real conversation). Has anyone ever heard of any radio behaving this way? Any thoughts on what would cause such behavior? I hate to guess at problems when I have no schematic or other service info for a particular radio. So the best I can give you is generic stuff. Is there a relay that might have dirty contacts? Or perhaps there is a defective voltage regulator in there somewhere. |
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Post by BBB on May 29, 2017 10:57:25 GMT -5
I'd vote for the dirty relay. Cleans up a bit after you key it a bunch of times. Then gets wonky after it sits for a while. Does it even have a relay in it? Can you hear a clicking sound inside the unit when you key?
If so, sometimes you can lift out the relay and get the cover off to clean the contacts with a brand new dollar bill or some other paper. Sometimes the relay is soldered down, but you still may be able to get the cover off for cleaning. Then simply slide the new bill back and forth a bunch of times between the contacts. You may have to manipulate the contact bar to clean the other side of the contacts.
Video of how to clean a similar relay:
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Post by BBB on Aug 6, 2017 9:09:58 GMT -5
Looks like we've got a BOT.
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Sandbagger
Administrator/The Boss
Posts: 6,247
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Post by Sandbagger on Aug 6, 2017 13:26:58 GMT -5
Looks like we've got a BOT. I'm not sure it's a BOT, but could be a potential spammer. I'll give them the 3 strikes rule. In any case a generic history lesson of the parent company is not helping to answer the specific question. |
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