Hello
I have a philco that on some schematics looks like one philco but sometimes looks like another and so on. It's in the 19 to 89 models.
I've been dealing with 19B.
The radio will not pick up any stations what so ever. I've replaced all the caps "as well as the electrolytics", replaced any non working or out of tolerance resistors. I've done the audio test on the 75 tube and got a hum. tapped the pk plates on the 42 tube got a 178v not 200v.
Checked all the coils for leakages and continuity. That's fine.
Found a broken wire on the 2nd IF transformer and repaired it. I found the contact for that fix job and found continuity but the last two contacts for the other part of the transformer no continuity. Not sure it 's supposed to have continuity.
Found a loose wire under the protective cover for the out put transformer for the speaker. I have no idea where it goes.
Does anyone out there have a pic of the protective cover removed from the output transformer? I have difficulty reading schematics. and tell me if the 2nd IF transformer on both sides of the coils are supposed to have continuity?
I know this is a lot of info here but desperation dictates.
Thanks
That speaker looks mighty strange. It appears that someone installed a smaller modern speaker underneath the original and rewired it to the original output transformer. The loose wire looks like it is the one that went to the voice coil of the original speaker which is no longer functional. Except for its field coil which is still being used as a power supply choke, the rest of its voice coil wiring is disconnected.
You are the first to mention that this doesn't look like the original speaker. I noticed and you can see at least one of them' two wire nuts. I being a relative newbie to this model have never seen wire nuts on original equipment unless tampered with.
That loose wire I found wrapped around the lug with a rivet holding it in place in the pic. Seeing as it was a dangling wire thought it broke of it's solder joint and put it back. Since this pic was taken I remove the wire from where I soldered it.
The rest of the wires coming from the voice coil are still attached to the transformer "three of them" hence my confusion.
Two other parts in question are the second IF Transformer with the broken wire" since fixed". and the part #4 in the schematic. The transformer had no continuity at all. since I re-soldered to it's lug, two lugs have continuity. The last two don't, Shouldn't the transformer have two separate sides of continuity?
The part #4 has five capacitors built in. According to the schematic it is called the 2nd IF Transformer. From what I read in different articles it is a very reliable part. It has the original caps inside smothered in tar. Should they be replaced as well?
Thanks for responding by the way.
Yes, the IF transformer should have continuity on both sides. Sometimes old solder joints are hard to measure and you need to use a sharp probe to get an accurate reading. I use something like this:
But be careful, you don't want to poke so hard that you damage the very little wires going to the lugs.
The capacitor block is #7 on the schematic I referred to earlier, and yes you should replace them....you can use the typical yellow 630V film capacitors that are available from most vendors. There is a member here (Buzz) who has posted Youtube links and one of his later ones shows him taking apart a can like that to replace the capacitors.
I'd also start looking for another speaker if I was serious about restoring this radio. I didn't notice wire nuts in your picture, but someone has been in there and used some modern wire for their repair. And if they crammed a modern speaker in there I'd be suspect of their other repairs.
John KK4ZLF
Lexington, KY
"illegitimis non carborundum"
It looks like your speaker is miswired. One side of the hum bucking coil looks to be connected to the bottom left terminal on the terminal board, that is wrong. The hum bucking coil is the pair of ribbon like wires. One should be connected to the output side of the output transformer (small copper wires that come out the bottom of the transformer). The other hum bucking wire connects to the voice coil.
After you get the radio working, if there is hum, you will need to reverse the connections to the humbucker.
Steve
M R Radios C M Tubes
(This post was last modified: 08-26-2014, 07:24 AM by Steve Davis.)
Quote:I'd also start looking for another speaker if I was serious about restoring this radio. I didn't notice wire nuts in your picture, but someone has been in there and used some modern wire for their repair. And if they crammed a modern speaker in there I'd be suspect of their other repairs.
Thanks for all the help......
I took apart the speaker and sure enough there was a modern speaker hidden inside the shell of the original speaker.
The blue , red and yellow are wires I replaced due to brittle and shredding original wires. I was careful to replace one end of each wire at a time.
Does anyone out there have a replacement speaker?
Hi Eliot Ness
I thought I should replace that block.
I looked up the part on a philco repair site. The voltage they show are as high as 2,000 volts. I already looked on the inside "carefully" to find five caps, I'm sure they are the same as the ones found in the bakelite blocks.
The 2nd IF Transformer only has readings on one pair of terminals. The other two terminals have no reading at all. I cannot find any broken wire in the windings. The wire I did find was visibly broken. Looks Like I will be replacing a couple parts.
confused1 Wrote:The part #4 has five capacitors built in. According to the schematic it is called the 2nd IF Transformer. From what I read in different articles it is a very reliable part. It has the original caps inside smothered in tar.
It sounds like you are going by the schematic for Model 89, Code 123.
Does it have a shadowmeter above the dial scale? If so, it is a Model 19. If not, it is an 89.
Does it have three knobs or four?
Is the second tube from left (when looking at the back of the chassis) a 36, or a 77?
While you're looking that up, let me address these comments, bear with me while I repeat:
confused1 Wrote:The part #4 has five capacitors built in. According to the schematic it is called the 2nd IF Transformer. From what I read in different articles it is a very reliable part. It has the original caps inside smothered in tar.
That is not the 2nd IF transformer. That must be the large rectangular metal can which contains five paper capacitors. It has different schematic numbers, depending on the version.
Hi Ron
I believe I have a 19B. Although the schematic I've been following hasn't the parts my philco has. All schematics are missing these parts.
The radio has four knobs, the #77 tube 2nd from the left and it does have a shadow meter.
I looked at my schematic and the rectangular silver box does contain five caps inside.
At the back of the unit there is what looks like a little bell. It is the #20 the 2nd IF Transformer of which I found a broken wire. I soldered that.
Someone replaced the original speaker with a modern one that doesn't work.
I have a lot to work on. This radio is going to teach me a lot.
If it has a 77 tube, it is a Phranken-Philco. Philco did not produce Model 19 sets with 77 tubes. So it's no wonder your parts are not matching up with any schematics.
Hmmm...I wonder if someone added a shadowmeter to a later version 89 chassis? This could cause all sorts of confusion, if the mod was not documented.
Can you take some photos of this chassis, topside and underneath, and post them here?
Like I said, post some photos. This will help to figure things out.
If we can determine with certainty exactly what you have (19 or 89), I might have a speaker for it. I still have too many speakers and I need to get rid of several.
Hey Ron
I attached a pic from another source what mine looks like. I think it's Identical except for the semi hidden electrolytic at the bottom of the pic. You can also see the 2nd IF Transformer on the bottom right which looks kinda like a side ways bell. The top left is the capacitor block with the five caps bundled inside. It's been suggested to replace it but the information I got from a philco site for that part recommends voltages in the 2,000 range, can 630 volts be used?
I would send you a pic of mine but I have replaced a few resistors and a many bad wires, it would get confusing.
I also attached the schematic that comes close to what my unit looks like under the chassis.
Does that shadow meter act very similar to those magic eye tubes?
I prefer to replace the speaker so that somewhere down the line it could be serviced again without all this fuss.
