Thanks guys. I was hoping for better news but had been afraid all along of 1 or 2 bad pills. If it's any help, mine is a 1st gen N4 with the Green Display. The current ones have the blue lights.
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RCI 2970 N4 Suddenly Lost Around 1/2 Power or more
- Thread starter Wire Weasel
- Start date
Unfortunately that's the outcome a lot of times with those internal amp sections.
But 4 matched hg's, replace the components that usually go bad when pills go and start over.
If you choose part with it, I could be interested in that 4 pill amp section.
@Wire Weasel
Please NOTE that the picture (you used) of the resistor you took out was a burned 5W 150Ω resistor is supposed to be 100Ω. . . . . DO NOT PUT IN ANOTHER 150Ω RESISTOR, IT CALLS FOR A 100Ω RESISTOR!!!!!
◙ The reason for a 100Ω (Brown-Black-Brown) resistor is because it is fed by two 50Ω amps, two pills is equal to one amp. If this 100Ω resistor gets hot or even warm to the touch while in use, means that there is a problem; either the pills don't match, or other parts between both pill sides don't match (like capacitors). ◙ Same goes for the Splitter resistor . . . it should also be a 100Ω if not already.
◙ Each two pill section should have matching "hfe", with all 4 pills having matching "hfe", otherwise known a "Matched Quad". Without knowing what you have now and just replacing one pill, could cause an imbalance that would heat up that 100Ω resistor while in use and burn up again.
Sometimes amps may have two 200Ω resistors in parallel which add up to 100Ω with twice the wattage.
If the use of a 150Ω resistor was in your circuit it could be the reason for the problem.
73
Please NOTE that the picture (you used) of the resistor you took out was a burned 5W 150Ω resistor is supposed to be 100Ω. . . . . DO NOT PUT IN ANOTHER 150Ω RESISTOR, IT CALLS FOR A 100Ω RESISTOR!!!!!
◙ The reason for a 100Ω (Brown-Black-Brown) resistor is because it is fed by two 50Ω amps, two pills is equal to one amp. If this 100Ω resistor gets hot or even warm to the touch while in use, means that there is a problem; either the pills don't match, or other parts between both pill sides don't match (like capacitors). ◙ Same goes for the Splitter resistor . . . it should also be a 100Ω if not already.
◙ Each two pill section should have matching "hfe", with all 4 pills having matching "hfe", otherwise known a "Matched Quad". Without knowing what you have now and just replacing one pill, could cause an imbalance that would heat up that 100Ω resistor while in use and burn up again.
Sometimes amps may have two 200Ω resistors in parallel which add up to 100Ω with twice the wattage.
If the use of a 150Ω resistor was in your circuit it could be the reason for the problem.
73
Thank You Frank. Actually ..... I'm not going to spend any money on this radio. May sell as is or keep running as is until more goes wrong with it and then could disconnect the amp and retune as run as a 2950 and put a separate amp behind it.
I say this as I'm in-between HF rigs right now but soon to get a 7300 for general HF and SSB use. Still lallygag around with the locals on 11 meters AM so need a loud AM CB and would use this RCI for that purpose.
If someone wants to make an offer for the N4 as sits still working as described in the opening post, you may send offers.
I say this as I'm in-between HF rigs right now but soon to get a 7300 for general HF and SSB use. Still lallygag around with the locals on 11 meters AM so need a loud AM CB and would use this RCI for that purpose.
If someone wants to make an offer for the N4 as sits still working as described in the opening post, you may send offers.