AM-radio is YELLING! (Was: CS1092-transistor)

[Matti Kaki]

Now I have replaced the defective transistor of my AM-radio.
I took the 3rd one and put it to the place of the 1st to
avoid interferences. It's now yelling like a small beast.
It's very microphonic and is also very sensitive of bending
the board. All the solderings are OK. How to find something
about this? I believe that the feedback isn't working properly.
This radio looks much like this one:

http://www.electronics-tutorials.com/receivers/rec-basic-fig1.gif

My radio is SUTTON 8-transistor AM-radio from year 1964.

Matti Käki OH2BIO

 

[Jerry G.]

You require the proper replacement part for the stage that you replaced the
transistor. Also, if the set is old, there are probably some other parts
that are worn out.

--

Greetings,

Jerry Greenberg GLG Technologies GLG
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"Matti Kaki" <oh2bioPOISTA@sci.fi.invalid> wrote in message
news:bnjbkp$8u6$1@phys-news1.kolumbus.fi...
Now I have replaced the defective transistor of my AM-radio.
I took the 3rd one and put it to the place of the 1st to
avoid interferences. It's now yelling like a small beast.
It's very microphonic and is also very sensitive of bending
the board. All the solderings are OK. How to find something
about this? I believe that the feedback isn't working properly.
This radio looks much like this one:

http://www.electronics-tutorials.com/receivers/rec-basic-fig1.gif

My radio is SUTTON 8-transistor AM-radio from year 1964.

Matti Käki OH2BIO

 

[**THE-RFI-EMI-GUY**]

Are the transistors in sockets? Some were back then. If so check that
the leads and sockets aren't tarnished. Also, it was the practice to put
a drop of molten parrafin in coils to hold the cores in place. Maybe one
is loose creating the microphonics. If it's motorboating you are
hearing, you likely have a bad electrolytic bypass capacitor.

Matti Kaki wrote:

Now I have replaced the defective transistor of my AM-radio.
I took the 3rd one and put it to the place of the 1st to
avoid interferences. It's now yelling like a small beast.
It's very microphonic and is also very sensitive of bending
the board. All the solderings are OK. How to find something
about this? I believe that the feedback isn't working properly.
This radio looks much like this one:

http://www.electronics-tutorials.com/receivers/rec-basic-fig1.gif

My radio is SUTTON 8-transistor AM-radio from year 1964.

Matti Käki OH2BIO

--
Joe Leikhim K4SAT


"Jazz is not dead. It just smells funny." -F.Z.