yo2550
Member level 2
From this thread https://www.edaboard.com/threads/242112/
I replaced D8, Q6, D13, D7, D1, R11.
Before replacing the components, the SWR read 1.13 but after replacing the components, the SWR read 1.4 using the same antenna.
The cause would be that I accidentally pulled out small circuit path on the board between R11 to Q26 and D8 to L15. I soldered the path to connect them already, but I am not sure if this would change the output impedance of the transmit signal, but I think it's unlikely.
I guess that the SWR goes up from 1.13 to 1.4 because the output impedance changed from 50ohm after I repaired the radio.
I hi-lighted the transmit signal path in the picture(red square). So, please give me a suggestion how to match the output impedance to come back to 50ohm. I have not put the metal cover over the transmit path as it was originally placed there. I'm not sure if it affects the output impedance.
I'm thinking about adding a capacitor to match the output impedance but not sure which point in the circuit I should put it to.
I replaced D8, Q6, D13, D7, D1, R11.
Before replacing the components, the SWR read 1.13 but after replacing the components, the SWR read 1.4 using the same antenna.
The cause would be that I accidentally pulled out small circuit path on the board between R11 to Q26 and D8 to L15. I soldered the path to connect them already, but I am not sure if this would change the output impedance of the transmit signal, but I think it's unlikely.
I guess that the SWR goes up from 1.13 to 1.4 because the output impedance changed from 50ohm after I repaired the radio.
I hi-lighted the transmit signal path in the picture(red square). So, please give me a suggestion how to match the output impedance to come back to 50ohm. I have not put the metal cover over the transmit path as it was originally placed there. I'm not sure if it affects the output impedance.
I'm thinking about adding a capacitor to match the output impedance but not sure which point in the circuit I should put it to.
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