Great job!! looks great. I have one that was my wifes Grandfathers. It needs work I would love to restore it, I'm just starting to read about it, and trying to find out the year and model. what forums have you found to be helpful. Thank you!!
Nice work! Old radios like this are among my favorite things on the planet.
The 5k pot was loading the
1st audio stage too heavily & causing low volume & amplitude distortion. The squealing is likely caused by regenerative feedback in an I.F. stage, causing oscillation which manifests as a beat note or heterodyne as you tune across a signal's carrier frequency. The culprit is probably either a bad screen bypass capacitor in that stage, a screen resistor that's drifted to too high a value.
You're right about the old paper dielectric capacitor in series with the tone pot. It's probably leaky & causing distortion as the pot's resistance is reduced.
Usually all the old caps, (other than the silver mica "postage-stamps") need to be replaced and also many of the old carbon comp resistors. I had to do this with a '49 National HRO-50. Most resistors will actually be 1/2W (old parts are always larger). If the original is >1/2W you'll see it's much larger than the others.
Thanks for all the advice! I did replace all the paper caps except the one in the tone control, I'll have to go and look at the resistors again, because many of them are origional
Right. Resistors often get overlooked. You'll find many @ more than 2x their original value. A good rule is that any resistor >20% off the marked value should be replaced. Carbon resistors connected to old, leaky capacitors or shorted tube elements may get hot & partially burn or disintigrate to a much lower value. Sometimes the evidence isn't easy to see, so you pretty much need to check them all with an Ohmmeter (de-soldering one end), or by checking voltage test points if you have that info.
Chassis "ground" connections are also sometimes bad. If they use a screwed solder lug, built-up oxidation and dirt, can cause a problem. Often, just backing it out & re-tightening will fix it as the screw/lockwasher re-bites into the metal. Cleaning the contact point first is best. Also, old solder joints can fail as the exposed wire oxidises. Look for noise, a loose-feel or a little dark ring-shaddow around the wire-end joining the solder. Re-heat using a dab of rosin-core flux or new solder.
Well its good that it dosen't... Lot of wooden radio's had a layer of asbestos under the chassis which is not a fun thing to get rid of lol. Just wanted to know before my 89 arrives...
It's good to see you're making more progress, but gotta say that the squealing is not supposed to be there, so there's still a little something not exactly right. Hang in there and you'll eventually figure it out. Probably a good alignment would eliminate most of it.
Thanks John :) Yes I've been playing with the alignment a little but I lack the proper test equipment to do a good alignment. I'll try asking on the forum, see what they say
About the capacitor your wanting , there is a way you can add two capacitors together to get the value you want it's just the opposite of resistors . When capacitors are added together in parallel their capacitance adds together to create a higher capacitance , and when they're added together in series their capacitance will be divided between the two capacitors to create a lower capacitance .
Very nice! that was a good repair job on replacing those electrolytics. Remember you can parallel values of caps to get the sum of the individual values in order to replace an unusual value.
Ah, the classic squeal, Lol! Great job on the repair. Sound lot better now. I hope someday you can find the cap for the tone control. I've used 1/2 watt resistors in my 1966 VM tube record player and performs great so I wouldn't worry about it. The original ones were 1/2 watts too.
Well it's great to see your making progress! I'm getting a philco 89 some time after christmas and i'll have to make a video when i get it. Maybe even a restoration vid...
I will try to make a video when i get it but it may take up to a month due to sending payment and it being shiped. The radio i got is the 2nd style 89 that was made in 1935...
I was going through the paperwork on mine and looking at the changes they made every month and I was able to pinpoint my radio's date of manufacture between Feb. and April 1933. I got the papers from a guy who photocopied them for me, Can't remember the exact website but if you google Philco radio his site will come right up.
Great job!! looks great. I have one that was my wifes Grandfathers. It needs work I would love to restore it, I'm just starting to read about it, and trying to find out the year and model. what forums have you found to be helpful. Thank you!!
debo693 5 months ago
@debo693 Antique radio forums all the way! good luck
coolbluelights 5 months ago
It squeals because it needs an alignment. The IFs as well as the front end and oscillator. Nice Job so far!
Radiosnmore5 2 years ago
Nice work! Old radios like this are among my favorite things on the planet.
The 5k pot was loading the
1st audio stage too heavily & causing low volume & amplitude distortion. The squealing is likely caused by regenerative feedback in an I.F. stage, causing oscillation which manifests as a beat note or heterodyne as you tune across a signal's carrier frequency. The culprit is probably either a bad screen bypass capacitor in that stage, a screen resistor that's drifted to too high a value.
Destry7 3 years ago
You're right about the old paper dielectric capacitor in series with the tone pot. It's probably leaky & causing distortion as the pot's resistance is reduced.
Usually all the old caps, (other than the silver mica "postage-stamps") need to be replaced and also many of the old carbon comp resistors. I had to do this with a '49 National HRO-50. Most resistors will actually be 1/2W (old parts are always larger). If the original is >1/2W you'll see it's much larger than the others.
Destry7 3 years ago
Thanks for all the advice! I did replace all the paper caps except the one in the tone control, I'll have to go and look at the resistors again, because many of them are origional
coolbluelights 3 years ago
Right. Resistors often get overlooked. You'll find many @ more than 2x their original value. A good rule is that any resistor >20% off the marked value should be replaced. Carbon resistors connected to old, leaky capacitors or shorted tube elements may get hot & partially burn or disintigrate to a much lower value. Sometimes the evidence isn't easy to see, so you pretty much need to check them all with an Ohmmeter (de-soldering one end), or by checking voltage test points if you have that info.
Destry7 3 years ago
Chassis "ground" connections are also sometimes bad. If they use a screwed solder lug, built-up oxidation and dirt, can cause a problem. Often, just backing it out & re-tightening will fix it as the screw/lockwasher re-bites into the metal. Cleaning the contact point first is best. Also, old solder joints can fail as the exposed wire oxidises. Look for noise, a loose-feel or a little dark ring-shaddow around the wire-end joining the solder. Re-heat using a dab of rosin-core flux or new solder.
Destry7 3 years ago
Does the 89 have any asbestos in it like a layer under chassis inside the cabinet or anything?
OldTimeRadioGuy 3 years ago
Nope, I've never even heard of them putting asbestos in there. are there some radios where they did?
coolbluelights 3 years ago
Well its good that it dosen't... Lot of wooden radio's had a layer of asbestos under the chassis which is not a fun thing to get rid of lol. Just wanted to know before my 89 arrives...
OldTimeRadioGuy 3 years ago
Thanks! good to know, I'll watch out for that when working on future radios
coolbluelights 3 years ago
It's good to see you're making more progress, but gotta say that the squealing is not supposed to be there, so there's still a little something not exactly right. Hang in there and you'll eventually figure it out. Probably a good alignment would eliminate most of it.
Regards,
John
joernone 3 years ago
Thanks John :) Yes I've been playing with the alignment a little but I lack the proper test equipment to do a good alignment. I'll try asking on the forum, see what they say
coolbluelights 3 years ago
About the capacitor your wanting , there is a way you can add two capacitors together to get the value you want it's just the opposite of resistors . When capacitors are added together in parallel their capacitance adds together to create a higher capacitance , and when they're added together in series their capacitance will be divided between the two capacitors to create a lower capacitance .
Highpoint211 3 years ago
Thanks alot! I knew there was a way I learned about it in school, but I couldn't remember which way it was
coolbluelights 3 years ago
I've also used heat shrink tubing to old brittle wires like on those speaker leads where it is difficult to totally replace the wire.
retrochad 3 years ago
Very nice! that was a good repair job on replacing those electrolytics. Remember you can parallel values of caps to get the sum of the individual values in order to replace an unusual value.
retrochad 3 years ago
Ok thanks! I wasn't sure if it was paralell or series
coolbluelights 3 years ago
Love the sound of an old tube radio! That squeal in there makes me feel like it's like 1935 or something lol!
krankiev 3 years ago
yea I half expect Herbert Hoover to come on lol
coolbluelights 3 years ago
Its working better and better. As long a the resistor is not over heating you should be ok. Great job D.
AllAmericanFiveRadio 3 years ago
Ah, the classic squeal, Lol! Great job on the repair. Sound lot better now. I hope someday you can find the cap for the tone control. I've used 1/2 watt resistors in my 1966 VM tube record player and performs great so I wouldn't worry about it. The original ones were 1/2 watts too.
damusician 3 years ago
it sound fairly good actually! good job!
1944johndeerel 3 years ago
Well it's great to see your making progress! I'm getting a philco 89 some time after christmas and i'll have to make a video when i get it. Maybe even a restoration vid...
OldTimeRadioGuy 3 years ago
Oh yes! please do! I'd love to see aother one get restored and see your methods^^
coolbluelights 3 years ago
I will try to make a video when i get it but it may take up to a month due to sending payment and it being shiped. The radio i got is the 2nd style 89 that was made in 1935...
OldTimeRadioGuy 3 years ago
It was either made in 1934 or 1935 but not to sure...
OldTimeRadioGuy 3 years ago
I was going through the paperwork on mine and looking at the changes they made every month and I was able to pinpoint my radio's date of manufacture between Feb. and April 1933. I got the papers from a guy who photocopied them for me, Can't remember the exact website but if you google Philco radio his site will come right up.
coolbluelights 3 years ago
After looking it up it's the 89b that was introduced in june of 1934 as a 1935 model...
OldTimeRadioGuy 3 years ago