klem kedidelhopper wrote in message
...
On Jun 6, 9:37 pm, mloo55 wrote:
If the radio is intermitent it does not mean that necessarily the
transistor, i think of one probable cause is the variable capacitor
besides if the transistor you mentioned is part of the if section
then you may check with another radio tuning a frequency so produces
an harmonics in the good radio so you know the mixer stage is working
then you can inyect a signal with your finger in the base of the first
if transistor and a radio station should be heard. Have you tried to
resolder all points and verify all paths are in god condition. Hope it
can help.
rgds



On Jun 4, 2:39 am, klem kedidelhopper
wrote:

I think I've found the transistor that is intermittently failing in
my
Grundig 305 transistor radio.It is an AF126. I obtained an NTE 160
which is supposed to replace the AF126. however I installed it and
the
radio does not work at all. I wouldn't think that I would have to do
a complete IF alignment after simply replacing a transistor, that is
I
would think that even if the new part detuned the circuit slightly,
I
would expect to get something through. Any opinions on this? Thanks,
Lenny

Hi...
I can send You a AF126. You pay the postage, the transistor You can
have for free.

Bo-Lennart Karlsson
Falun, SWEDEN

Hi, What do you think the postage to the US will be? Thanks, Lenny- Hide
quoted text -

- Show quoted text -

Well the odd thing is that the radio always starts out working
perfectly. It will run consistently for anywhere from ten minutes to
sometimes two hours. It seemed that at first operating it at low
volume settings may have precipitated the problem but now I'm not so
sure about that. However once the intermittent condition begins it
continues until the unit is shut off for a period of time. After that
the period of time it takes for the intermittent condition to start
again after a subsequent power on is directly proportional to the time
the radio has been off. I managed to measure all transistor voltages
during an "OK" period. I then took similar voltage readings during
failure. As expected all voltages on all transistors were affected,
however the voltages measured at the terminals of this particular
transistor in question are all the same, (about 3.0volts) when the
failure condition occurs. It was for this reason i suspected this
transistor, (as improbable as this may seem), of developing what looks
like a "dynamic" b e c short. Lenny

++++

In that case look for C problems