Dan,
that only means the 6 or 12 volt filament tap on the power transformer works. i would assume then,the entire transformer is working.you can always put an ohm meter across the secondary. first thing to do is replace the old high voltage filter capacitors right away. Since, if it's stereo, you have 2 complete channels in the amplifer sec..it's unlikley both outputs are open or both preamp triodes and output tubes are bad. If there is not even the slightest hum in either channel or otherwise noise to let you know...then i would say you have a B+ network problem..Get a scheme and an ohm-cap meter and work through the B supply to the output and preamp tubes.
If you do have some kind of indication the amp is working then work back up the af- rf chain looking for bad coupling caps, open resistors, or other R/C problems.. Barring the fact all the tubes show good in a tester.(just because they light doesnt mean a thing)
often you can spot badly heated resistors and poped caps visually.. tapping around with the butt end of a screwdriver with power on will often locate an intermittant connection,,
10 to one if you have no hum or hear anything at all when you switch on the set,,,it's a power supply problem..
dave
: Dan,
: that only means the 6 or 12 volt filament tap on the power transformer works. i would assume then,the entire transformer is working.you can always put an ohm meter across the secondary. first thing to do is replace the old high voltage filter capacitors right away. Since, if it's stereo, you have 2 complete channels in the amplifer sec..it's unlikley both outputs are open or both preamp triodes and output tubes are bad. If there is not even the slightest hum in either channel or otherwise noise to let you know...then i would say you have a B+ network problem..Get a scheme and an ohm-cap meter and work through the B supply to the output and preamp tubes.
: If you do have some kind of indication the amp is working then work back up the af- rf chain looking for bad coupling caps, open resistors, or other R/C problems.. Barring the fact all the tubes show good in a tester.(just because they light doesnt mean a thing)
: often you can spot badly heated resistors and poped caps visually.. tapping around with the butt end of a screwdriver with power on will often locate an intermittant connection,,
: 10 to one if you have no hum or hear anything at all when you switch on the set,,,it's a power supply problem..
: dave
I recently found a Grundig Majestic SO 102/60PX in my grandmothers basement, works perfectly, except for the turntable. How do I tell the year and value etc...
Hi Daniel
I think, Dave is right to look at the anode's power supply.
Now what you also should do with old Grundig's: The caps
for coupling and filtering except the electrolytic ones are
often of the type ERO 100. They are wax-sealed paper capacitors.
The wax shrinked and broke in the last 40 years, humidy got in
and if it's a coupling cap the following tube is not happy about this.
I replace them without testing by better ones wherever possible.
I hope i can find out when the Grundig was made but it should have been
sold here in Germany too (not export version only).
See also 'Grundig 7015 selenium rectifier replacement' in this forum .
Good luck !
2120 radio. I would like some info on when it was
made and how much it's worth.
Thank You.
Bob M.
Here in Los Angeles area
A follow-up - my Grundig is a 7050/USA. Does anyone know where to go to get it in working order?
does anyone know where i can get it serviced or information regarding replacement parts (tubes)