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No modulation on HF?


 

The ic is a m5207L01 that is a stereo volume controller. PIN2 = output, PIN3 = control 0-5 volt, PIN4 = input.
The datasheet can be found here
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Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.


 

Thank you. I also notice that at the ssb there is no signal, of course im only using a osciloscope


 

Put the transmitter in SSB.
Mic gain 12 o clock position.
Inject a 1KHz tone at 3mv level to the MIC jack (pin 8 = mic input, pin 7 = ground)
Use a old amplified computer speaker, to trace the 1KHz tone, at the points below:
  1. Q1053 (M5207L01) pin 4,
  2. With a DC voltmeter, Q1053 pin 3, must be around 2.5 Volts, and changing when rotating MIC Gain,
  3. Q1053 pin 2, amplitude changes when rotating MIC Gain,
  4. Q1081 (BU4053BCF) pin 14,
  5. Q1038 (NJM2902M) pin 7,
  6. Q1038 (NJM2902M) pin 8,
  7. Q1081 (BU4053BCF) pin 15,
Please let us know your findings.
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.


 

--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.


 

Will do this saturday, I'll let you know. Thanks


 

Hi Rafael,
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Any luck on finding the fault?
--
Greetings from Erik Rothuis (PA2ER), Terborg Netherlands.