Sony TFM-6060W..

[rtsherrod]

Hello all,

My first post here at videokarma, but a frequent visitor of audiokarma for my other addiction.

I have among my collection of transistor radios a Sony AM/FM portable, model TFM-6060W. In my frequent use of this radio, I've noticed that it isn't very sensitive to local low power stations, but picks up the more powerful stations without issue. So, out of curiosity, I grabbed my tools, DMM, a fresh 9V and the service manual and did some measurements.

I checked all of the voltages for the transistors that were identified on the schematic as well as the other test points. I found that all were within a few tenths of a volt, or in a few cases a few tenths of a mV except for Q1 and Q2. Q1 is the FM RF Amp and Q2 is the FM Converter, both are 2SC710. The voltages as listed on the schematic are compared to those as measured below:

Schematic Measured

Q1 Base -1.1V -4.47V
Q1 Collector 0V 0V
Q1 Emitter -5.5V -5.3V

Q2 Base -1.25V -4.36V
Q2 Collector -0.35V -75.7mV
Q2 Emitter -4.85V -5.06V


I currently don't have enough of an understanding to know why the voltage discrepancy exists. Could someone give me an idea? Do they need to be replaced.

Any help is greatly appreciated.

Thanks,

Bobby

[rtsherrod]

The measurement information didn't show as intended. The first value is what is defined on the schematic; the second value as measured.

Thanks,

Bobby