07-16-2017, 06:28 PM
Hi, everyone:
I'm trying to restore the rusty innards of what was a decent looking 71B Cathedral I won at a recent radio club auction. It was advertised as an 18B, but since I just wanted a Philco cathedral and didn't care what model, I bid on it and won it at a decent price. Just because a radio "self identifies" as an 18B doesn't make it one, and it was born a 71B Code 125.
The cabinet looked like it was restored, but not perfectly, yet clean enough to display. Looking at the chassis and doing some digging I figured out this is a seemingly rare 71B Code 125 with the shadow meter when most of them did not have this.
It played (well, on the upper end of the dial anyway) but the shadow meter wasn't working. I finally decided, after doing my 70 (my first 30s Philco), it was time to pull out the chassis of this "restored" radio and see what's wrong with the shadow meter and touch up the IF alignment after successfully doing that on my 70. Oh, if only it was that simple, it would be back on the air now!
Well, wow, the things you see when you flip this chassis over are shocking, and aside from the rust, globs of RTV silicone everywhere, and wrong value capacitors just globbed onto the Bakelite units (with some lug clippage to add insult to injury). I'm going to have to just start on one end and clean up every problem I find, including the roll of old electrical tape that was used to turn the dial because the original string is long missing, and someone decided that electrical tape and a small piece of fuel hose would make a good tuning washer for someone with a strong tuning hand.
Anyway, I have a few questions:
The tuning capacitor is so nasty I'm amazed it picked up anything at all. I found one that looks the same out of a 70 on eBay. I know the Philco part numbers are different, but is there anything electrically different between a late 71 and a most-likely early (non AVC) 70 tuning condenser? The actual dial portion unbolts from the front with one screw, so I would hope the 71 style dial and shaft assembly will fit on the 70 condenser.
What about a dial stringing diagram? I've searched the web and found lots of dead links promising a cord stringing diagram, but delivering ads or 404s instead. The Sam's dial stringing guide doesn't show the 71 either.
As far as a schematic is concerned, the best I can find is the Philco 71 series, which at first glance looks like it matches except for the shadow meter. Since I see the leads (non-original) of my shadow meter are soldered across a jumper (shorted) and since the shadow meter appears to be open on top of that, I'm wondering how it was originally installed, and if Philco issued a revised schematic for this, or if there was a more common shadow meter radio with the same circuit I could use.
I would really like to find a better, less butchered and less rusty chassis to work on, but my research seems to suggest this will be difficult. I'm not talking about surface rust like you find on many of these. I'm seeing chunks of metal flaking off the sheet metal, making me think I'm going to have to go find some Bondo and silver paint to try to clean this thing up! Reminds me of an episode of Graveyard Cars.
Anyway, any help and advice from the members here would be appreciated.
And, a lesson I hope people have learned over the years is, please upload pictures and documents directly to this web site instead of relying on outside links. I've seen Photobucket links that return errors because whoever posted it didn't renew their account, and links to a variety of "404 Not Found" pages.
Thanks!
I'm trying to restore the rusty innards of what was a decent looking 71B Cathedral I won at a recent radio club auction. It was advertised as an 18B, but since I just wanted a Philco cathedral and didn't care what model, I bid on it and won it at a decent price. Just because a radio "self identifies" as an 18B doesn't make it one, and it was born a 71B Code 125.
The cabinet looked like it was restored, but not perfectly, yet clean enough to display. Looking at the chassis and doing some digging I figured out this is a seemingly rare 71B Code 125 with the shadow meter when most of them did not have this.
It played (well, on the upper end of the dial anyway) but the shadow meter wasn't working. I finally decided, after doing my 70 (my first 30s Philco), it was time to pull out the chassis of this "restored" radio and see what's wrong with the shadow meter and touch up the IF alignment after successfully doing that on my 70. Oh, if only it was that simple, it would be back on the air now!
Well, wow, the things you see when you flip this chassis over are shocking, and aside from the rust, globs of RTV silicone everywhere, and wrong value capacitors just globbed onto the Bakelite units (with some lug clippage to add insult to injury). I'm going to have to just start on one end and clean up every problem I find, including the roll of old electrical tape that was used to turn the dial because the original string is long missing, and someone decided that electrical tape and a small piece of fuel hose would make a good tuning washer for someone with a strong tuning hand.
Anyway, I have a few questions:
The tuning capacitor is so nasty I'm amazed it picked up anything at all. I found one that looks the same out of a 70 on eBay. I know the Philco part numbers are different, but is there anything electrically different between a late 71 and a most-likely early (non AVC) 70 tuning condenser? The actual dial portion unbolts from the front with one screw, so I would hope the 71 style dial and shaft assembly will fit on the 70 condenser.
What about a dial stringing diagram? I've searched the web and found lots of dead links promising a cord stringing diagram, but delivering ads or 404s instead. The Sam's dial stringing guide doesn't show the 71 either.
As far as a schematic is concerned, the best I can find is the Philco 71 series, which at first glance looks like it matches except for the shadow meter. Since I see the leads (non-original) of my shadow meter are soldered across a jumper (shorted) and since the shadow meter appears to be open on top of that, I'm wondering how it was originally installed, and if Philco issued a revised schematic for this, or if there was a more common shadow meter radio with the same circuit I could use.
I would really like to find a better, less butchered and less rusty chassis to work on, but my research seems to suggest this will be difficult. I'm not talking about surface rust like you find on many of these. I'm seeing chunks of metal flaking off the sheet metal, making me think I'm going to have to go find some Bondo and silver paint to try to clean this thing up! Reminds me of an episode of Graveyard Cars.
Anyway, any help and advice from the members here would be appreciated.
And, a lesson I hope people have learned over the years is, please upload pictures and documents directly to this web site instead of relying on outside links. I've seen Photobucket links that return errors because whoever posted it didn't renew their account, and links to a variety of "404 Not Found" pages.
Thanks!
