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Yet another stubborn model 60
#1

I've restored two other model 60's without a problem (on both all coils were good). This one, a run #7, is proving to be a real challenge. Very reminiscent of my model 89 about 3 years ago.

Here's the schematic:

http://www.philcoradio.com/images/phorum/60g.jpg

Both the outer primaries of the OSC and ANT coils were open. Nothing surprising there, as from what I've heard this is fairly common on 60's. I rewound both with 38 ga wire, taking careful notes as to what went where and especially the direction of the winding. 18 turns on the OSC, 4 turns on the ANT. When completed, all ohm values were as they should be on the schematic Icon_thumbup  Reinstalled each, double checking the resistances and again, all was well.

However, the set tries to receive stations but everything is hopelessly garbled...up to around 1200 on the dial. There is drops off to silence.

The set has been recapped, save for the two bakelite blocks with the .00011 mfd. caps in. I'm waiting for some 100 pf to replace those with. All the out of tolerance resistors were replaced as well.

I'm going to double check the voltages tomorrow night but before heading back upstairs from the basement workshop, I did a quick but crude test by touching the grid caps of the 75, 78, and 6A7 tubes with the soldering iron. They should produce a loud buzz doing this, similar to touching the center tap of the volume control. I'm only getting that buzz on the #75 tube. The 78 just causes silence when I touch the grid and the 6A7 makes a slight buzz. The antenna jack is working, though, as the garbled noise does get louder when I touch it (I have about a 4' piece of wire attached to it already).

Not sure what is causing the drop off at 1200 on the dial and garbled sound. I know the coils were wound in the correct direction and to the correct lugs. Anyone else experience this and can tell me what they did to correct it?

Greg V.
West Bend, WI
Member WARCI.org
#2

> 18 turns on the OSC, 4 turns on the ANT.
I'd pop out the osc coil and add a few more turns like 4 maybe. Sound like there's not enough feedback.
Which section of the ant did you rewind? The thingy you have in red is the IF trap below that is the bc part of the ant coil @11ohms w/#38 wire is going to be about 12' of wire. the bottom section is for the pol band and should be about a foot of wire. If that is open it will make the signals garbled.

GL

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
#3

Finally got back to the radio this afternoon. The good news is, I got rid of the garbled sound. Turns out it was the #33 bakelite block. Once I got a new .015 cap in there (and the 100 pF I was waiting for), it started playing loud and clear. But, it still cuts out at 1200 on the dial. I get a ton of stations before that....even Chicago and Nashville, but it's a dead cut out at 1210. Dead silence. Now to prove that it's not a fin of the tuning capacitor touching another fin and shorting out, I was able to move the stations up the dial and get stations and static throughout the dial by adjusting the OSC trimmer on the back of the chassis. Of course at the low end I had 670, so the high end wound up around 1000. So I ruled out the tuner itself.

I know Terry suggested taking out the OSC coil and adding a few more turns to the 18 I have on the primary I rewound. I'm just wondering if anyone else has had success doing this or if there's something else I should be looking at first? Just trying to eliminate all other variables before I go to the trouble of rewinding again. All caps....including 'lytics & micas and all resistors have been replaced in the set.

Greg V.
West Bend, WI
Member WARCI.org
#4

So no one else has encountered the "dead over 1200 on the dial" syndrome? Have extra windings on the primary helped this situation?

Greg V.
West Bend, WI
Member WARCI.org
#5

(12-09-2016, 02:09 PM)NostalgiaRadioTime Wrote:  So no one else has encountered the "dead over 1200 on the dial" syndrome? Have extra windings on the primary helped this situation?

You don't have to rewind the coil just cut the primary wire at the terminal, solder on a new length to complete the extra turns. And start winding! [Image: http://philcoradio.com/phorum/images/smi...n_razz.gif] I'd cut it loose from the top.

<Just trying to eliminate all other variables before I go to the trouble of rewinding again. All caps....including 'lytics & micas and all resistors have been replaced in the set.
I would think that if you can get #12 to set the dial to a station at the low end and the the stations up by 1200 or so are close to frequency the resonant portion of the tuned circuit is working us it should. How is the pol band??

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
#6

Thanks. If tge turns aren't perfectly tight together (the windings) I imagine that can have an adverse affect too? Very hard to get it perfectly tight with 38 ga wire. Icon_smile Haven't received anything on the police band. It's pretty much dead silent.

Greg V.
West Bend, WI
Member WARCI.org
#7

(12-09-2016, 03:19 PM)NostalgiaRadioTime Wrote:  Thanks. If tge turns aren't perfectly tight together (the windings) I imagine that can have an adverse affect too? Very hard to get it perfectly tight with 38 ga wire. Icon_smile Haven't received anything on the police band. It's pretty much dead silent.

>I imagine that can have an adverse affect too?
Some.
>Very hard to get it perfectly tight with 38 ga wire.
It's not too bad, a good strong pair of readers and or a luxo lamp help a lot.
> Haven't received anything on the police band. It's pretty much dead silent.
Tried a sg?

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
#8

I wouldn't care about police band if this were the only trouble. There's nothing on it.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
#9

Well, I wasn't having good luck splicing that fine wire, so I started over and rewound the primary of the OSC coil. This time I went 22 turns instead of 18. It then measured 4.0 ohms instead of the 3.4 shown on the schematic.

I carefully gator wired it together out of the chassis just to see how it would react before soldering it back in place. I was getting the high end of the broadcast band....the strong local station at 1470...in two places on the low end of the dial (600 and 650). This was followed by the rest of the low end of the dial. All the familiar local stations. Now mind you the OSC coil was laying on its side on a piece of cardboard, so there was no "can" around it. I figured a proper alignment would move the dial back into positon so I soldered it back in. In doing so, the local stations from the low end of the dial to 1200 appeared back as they should, and the strong local disappeared from the low end...and altogether. In spite of an alignment I'm still not getting anything over 1300 on the high end but at least now it doesn't cut out to dead silence. I at least get static and am now getting static on the PB too. I get a TON of stations up to the 1300 point though, so I decided to button it up for now. I did the best I could. I don't believe more turns on the OSC primary beyond the 4 extra I did is the answer. It may even be caused by some sort of defect in the secondary section (although it does measure the correct value per the schematic). After twice winding with the OSC coil and once with the ANT coil, I need to unwind myself and move on to a different project! Icon_lol 

Incidentally, this set was hit by lightning as there was a dark black spot on the ANT coil right under the primary winding. It also was badly corroded with what looked like sea salt on the aluminum IF cans. Not to mention a badly peeling cabinet requiring major veneer replacement. It had a rough life but it least it's singing again. I'm happy about that Icon_thumbup

Greg V.
West Bend, WI
Member WARCI.org




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