12-05-2020, 08:00 PM
I put the little fuzzy glides on the bottom of the 38-17F and call it done for now and back to the 16B. Over the last week or so I've restuffed the bakelite caps, found one that had a cap and a 250 ohm resistor in it too, cut open the ecap and fitted it w/2 10mfd caps, checked the carbon resistors, rebuilt the five section bypass cap, and a bunch of other stuff...
The coneless speaker got a small pm speaker connected to it for test purposes and made up the speaker cable. Couldn't find a Philco speaker socket to add to the chassis at this point. For now it's just temporarily connected as it will be headed over to Sound Remedy.
Had everything wired up and the 80 in place flipped the switch and voltmeter swung up to 300v but no sound. Hmmm no plate volt on the 77 1st audio missing resistor. Fixed that had audio but no signal. Measured some random voltages and found the screen grid voltage for the mixer and IF amps was 30v hmmm seem lowwwwww. Put a pin in it and warmed up the generator and aligned the IF. It passed a signal but wasn't overly sensitive.
Now for the rookie mistake. I assumed that the set was working more or less when it was retired. I didn't pull all of the tubes and check them out. Someone had swapped a 6C6 for the 77 mixer, bad move. They have the same base connection and electrically are similar but didn't work at all in this set. Replaced w/a 77 and started playing fine. The 30v then up to 80v.
I did find one common thing that I was wondering about. On both of these 16's the 1st position of the tone switch seems to have some level of treble cut. Sound just a little muffled. I was fooling around with contact and sound brighten up. I'm thinking that there is leakage at that contact.
Still lots to do. Shadow meter bulb holder is broken, grommets for the tuning cap, a good clean it's filthy, fix up Rube Goldberg dial drive, remove the IF transformer covers and clean/replace grid wires, do like wise w/the rf coil covers, and maybe give the choke and driver transformer a lick of paint.
It's been playing for abt 4hrs and hasn't burst into flames or set my domicile on fire. Transformer is warm but not hot so all is good.
The coneless speaker got a small pm speaker connected to it for test purposes and made up the speaker cable. Couldn't find a Philco speaker socket to add to the chassis at this point. For now it's just temporarily connected as it will be headed over to Sound Remedy.
Had everything wired up and the 80 in place flipped the switch and voltmeter swung up to 300v but no sound. Hmmm no plate volt on the 77 1st audio missing resistor. Fixed that had audio but no signal. Measured some random voltages and found the screen grid voltage for the mixer and IF amps was 30v hmmm seem lowwwwww. Put a pin in it and warmed up the generator and aligned the IF. It passed a signal but wasn't overly sensitive.
Now for the rookie mistake. I assumed that the set was working more or less when it was retired. I didn't pull all of the tubes and check them out. Someone had swapped a 6C6 for the 77 mixer, bad move. They have the same base connection and electrically are similar but didn't work at all in this set. Replaced w/a 77 and started playing fine. The 30v then up to 80v.
I did find one common thing that I was wondering about. On both of these 16's the 1st position of the tone switch seems to have some level of treble cut. Sound just a little muffled. I was fooling around with contact and sound brighten up. I'm thinking that there is leakage at that contact.
Still lots to do. Shadow meter bulb holder is broken, grommets for the tuning cap, a good clean it's filthy, fix up Rube Goldberg dial drive, remove the IF transformer covers and clean/replace grid wires, do like wise w/the rf coil covers, and maybe give the choke and driver transformer a lick of paint.
It's been playing for abt 4hrs and hasn't burst into flames or set my domicile on fire. Transformer is warm but not hot so all is good.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
