Re: K3s no power on TX


Brian KF6C
 

First let me thank you all for your suggestions,  all were very much appreciated.

These units have been removed from the radio:
K144XV
KRX3A,
KPA3A,
KBPF3.

I have also removed the KAT board and made a direct connection.

There is low power output in the KXV3 test mode.

The KLPA3A is Rev B. Looking at the schematic, taken from the web,  which is also for Rev B there are differences between what the schematic shows and what is in the radio. There are 2 relays KL2 and KL3 on the schematic that are not on the board in the radio.

With tune on there is 1 volt p to p input and 2.4 volt p to p output on the KLPA3A.There are no change in these readings on power control adjustment. I have not yet understood how power control adjustment is implemented.

4 dBm would seem adequate drive for the  KLPA3A.

What is the part number of U4 is not given on the schematic?

I have not seen anything obviously wrong on the KLPA3A but the voltage gains throughout seem low.

73 Brian KF6C.

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