"The "audio diode" is actually a pair of coils tuned to the IF frequency and providing the audio signal and AGC voltage from the diodes in the 6B8G tube. The diode(s) are actually in the tube! The component would have been…"
The Fine Things are Always Hand Made
jonathan dollimore's Discussions
Problem with Philharmonic.
Started this discussion. Last reply by Norman S Braithwaite Feb 19. 13 Replies 0 Likes
I know it’s notoriously difficult to diagnose faults remotely, but I’m a bit stumped and so decided to ask. My philharmonic has developed this problem: essentially, it’s behaving as if it hasn’t got…Continue
Philharmonic with Capehart 16e
Started this discussion. Last reply by jonathan dollimore Feb 5. 7 Replies 0 Likes
I have decided to part with my Philharmonic and Capehart 16E. Both were professionally installed in a custom made cabinet made in London in the late 1930’s. I am in East Sussex, in the UK. I have a…Continue
Philharmonic tapped volume control.
Started this discussion. Last reply by Scott Seickel Sep 18, 2022. 4 Replies 1 Like
I posted about this a few weeks back, looking for a replacement.I’ve been unsuccessful in finding a replacement, and nor can see how to fix the original. I’ve dismantled it and can't see any damage…Continue
Caps under Coil shields on Philharmonic?
Started this discussion. Last reply by Norman S Braithwaite Sep 25, 2022. 9 Replies 0 Likes
The McMurdo Silver sets have caps above chassis, under the chrome coil shields. Do the Scott Masterpiece sets have them also, or are all the caps on these sets underneath the chassis? I ask because…Continue
jonathan dollimore's Page
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"Can I ask - what exactly is the function of the audio diode?
thanks, J"
"Thanks Norman and David. The set was restored by or for the previous owner. I’m now trying to address the things that weren’t done then, and your advice helps greatly."
"If you had not recapped the 3 diodes, what about the others out of sight: one inside the big tuning cap cover.
Also, the for the pointer non-FM Philharmonics, the left rear between the expander tubes and the pair if 3 rd audios is a rectangular box.…"
"The resistors were run through holes in the shield to maximize shielding of the diode coil. There are wax-paper capacitors inside the diode shields. They need to be replaced. The resistor that failed most likely did so because a…"
"Thank you for your help on this. The set has now gone silent though still lit. I have discovered a burnt out resistor in the audio diode. It’s R9, 1k/1/4 watt. I notice that this resistor, and the other one in the diode (and those in the other…"
"Simple. Energy received at the antenna. Scott receivers will pick up strong signals even when the IF amplifier is well out of alignment but will be noisy and not receive more distant signals well.
Norman "
"Thanks for your suggestions. I’ve already checked the IF valves and aim to do the others this weekend. Meanwhile, does anyone have an explanation as to why the set works fine with a transmitter, but not the conventional signal? I’d hoped…"
"Perhaps. You should check the variable selectivity rotors. At some point during expansion of the pot metal collars the rotor will come fully loose from the variable selectivity shaft and rotate to a point that gravity dictates rather…"
"Hello Norman, the problem is of sudden onset , so probably not an alignment issue?"
"If voltages are reasonable, the IF alignment is a prime suspect for the symptom you describe. Has the set been aligned and recently checked? Are the variable selectivity rotors well secured to the variable selectivity shaft? Pot…"
"+1 to Alex' comment, especially the tubes in the front end and AGC circuits.
Kent"
"Have you went through and checked all your tube socket voltages? That's a good starting point. "
Problem with Philharmonic.
I know it’s notoriously difficult to diagnose faults remotely, but I’m a bit stumped and so decided to ask. My philharmonic has developed this problem: essentially, it’s behaving as if it hasn’t got a good aerial when in fact it has- ie poor sensitivity and poor signal to noise ratio. However if I beam a signal to it from an SS tran AMT3000 transmitter, it works very well. Any thoughts?See More
"Thank you Troy!"
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