Uher EG740 tuner from 1979 probably

[N_Cook]

Used every day,on FM, until one day, switching on and very low level
audio out. Tuning is fine on FM and AM is normal. Phono and Aux inputs
to amplifier are normal. Schematic on elektrotanya. Nothing loose found
on twizzling. There are some ceramic resonator filters, I'm aware of
silver migration over such time spans , resulting in attenuation of
throughput, anything else to zero-in on?
Lots of Din connectors connecting tuner to preamp and amp, power ,
signal and control connections. Any advice on improving contacts other
than needle insertion to tension up the socket yokes a bit.

 

[Helmut Wabnig]

On Mon, 27 Oct 2014 13:49:18 +0000, N_Cook <diverse@tcp.co.uk> wrote:

Used every day,on FM, until one day, switching on and very low level
audio out. Tuning is fine on FM and AM is normal. Phono and Aux inputs
to amplifier are normal. Schematic on elektrotanya. Nothing loose found
on twizzling. There are some ceramic resonator filters, I'm aware of
silver migration over such time spans , resulting in attenuation of
throughput, anything else to zero-in on?
Lots of Din connectors connecting tuner to preamp and amp, power ,
signal and control connections. Any advice on improving contacts other
than needle insertion to tension up the socket yokes a bit.

Contact spray
http://www.youtube.com/watch?v=q1BxYWlT2yc

w.

 

[N_Cook]

On 27/10/2014 21:22, Helmut Wabnig wrote:

On Mon, 27 Oct 2014 13:49:18 +0000, N_Cook <diverse@tcp.co.uk> wrote:

Used every day,on FM, until one day, switching on and very low level
audio out. Tuning is fine on FM and AM is normal. Phono and Aux inputs
to amplifier are normal. Schematic on elektrotanya. Nothing loose found
on twizzling. There are some ceramic resonator filters, I'm aware of
silver migration over such time spans , resulting in attenuation of
throughput, anything else to zero-in on?
Lots of Din connectors connecting tuner to preamp and amp, power ,
signal and control connections. Any advice on improving contacts other
than needle insertion to tension up the socket yokes a bit.


Contact spray
http://www.youtube.com/watch?v=q1BxYWlT2yc

w.

At least that is a "do no harm" activity.

Uses 4x 10.7M ceramic resonators, the resistance associated with 2 of
them , is from the rest of the circuitry
Looks like it was a retrofit electrolytic to a 9.4V line, with a large
component side solder blob that had corrossion product that touched a
bare bridge wire from the mute line of the main control IC.