[Steve Davis]

About two years ago, I started the restoration of a Philco 19 chassis. I did a total recap, replaced a few out of tolerance resistors. The feedback winding of the oscillator coil was open. I removed the coil, unwound the tickler and baked the form at 200 degrees for about an hour. I rewound the coil and installed it in the chassis. When I started to do the alignment, I discovered, the oscillator would die out on the low end of the dial (I believe it was the low end, it's been a while). I had already changed the oscillator cathode resistor to 10K. I tried another tube, no good. I then tacked another resistor in parallel to the 10K to bring the resistance down to about 7500, still no good.

I have restored four or five 19/89 chassis and this was the first time I was unable to get the oscillator to work. I waved the white flag and put the radio back on the shelf. About two months ago, I decided to take another crack at it. I removed the coil and added a couple more turns to the feedback winding. After reinstalling, the oscillator would not work at all. I'm sure I messed something up when I installed the coil but. At that point, I was pretty discussed. I made the decision to do Ron's "Super" mod.  Take a look here   http://philcoradio.com/phorum/showthread.php?tid=14919

  

I didn't have a very good seven pin tube socket so, I ordered a few made in China ceramic sockets. I had an extra coil form so, while waiting for the sockets to arrive, following Ron's instructions, I wound the new oscillator coil.


[Image: https://c1.staticflickr.com/3/2942/33618...115d_k.jpg]109_0238 by Steve Davis, on Flickr
The sockets arrived. They look to be well made.      
                                                                                 [Image: https://c1.staticflickr.com/3/2937/33618...5659_b.jpg]109_0240 by Steve Davis, on Flickr      More to come in a few days.   Steve

[Ron Ramirez]

This should be a great thread! I came very close to doing that with a model 19B last weekend...but finally, after a very long alignment session, it straightened out and began tracking properly across the band.

[Kenneth F. Besso Jr.]

That socket seems to be the tightest tube socket ,,,I have ever seen,,,bought 2 of them ,,,Myself for radio,,,,

[jcassity]

wow,,, can t figure out what more to say,, thats some very bad a** looking coil work for sure!

BTW,, i think play things of the past has 7pin sockets.

yeah,, i just checked he has a lot,, mostly 50cents to 3$ ea

[Mondial]

Make sure you get the small 7 pin sockets for the 6A7. The 7 pin comes in two sizes, small for the 6A7, large for the 59 and transmitting tubes like the 1625. 

They are not interchangeable, but you may be able to force fit the tube in the wrong size socket which would not be recommended.

[Arran]

Another factor to watch with some Chinese replacement tube sockets is that they are designed to fit under the chassis verses on top of the chassis. That metal mounting flange looks like it's for the later, but it could probably be taken off, flipped over, and remounted to the socket.
Regards
Arran

[Ron Ramirez]

The original Philco sockets in the 19 fit under the chassis.

[Steve Davis]

The socket is the small seven pin. It looks like the hole in the chassis will have to be enlarged slightly.

 [Image: https://c1.staticflickr.com/4/3937/32904...7c96_b.jpg]109_0243 by Steve Davis, on Flickr

I have to work this weekend, so it will be sometime next week before I will be able to get back to project.

Steve

[Steve Davis]

I had some time to work on the radio today. I forgot to take pictures until almost finished.   The tube socket looks like it was meant to be mounted on the top side of the chassis. I figured out that I could do a bottom mount by using spacers about a 1/4 inch long between the mounting "ears" and the chassis. I had to enlarge the hole in the chassis about 1/8 inch so that the porcelain portion of the socket would protrude.


[Image: https://c1.staticflickr.com/4/3666/32904...dc74_b.jpg]109_0245 by Steve Davis, on Flickr

 I removed the original oscillator coil and installed the modified coil. Following Ron's instructions I began reconnecting everything. Ron's instructions were clear and easy to understand. It reminded of assembling "Heathkits" years ago. 
[Image: https://c1.staticflickr.com/4/3951/33436...1ffa_b.jpg]109_0253 by Steve Davis, on Flickr
After looking at pictures of Ron's restoration, I'm almost ashamed to show pictures of mine! I do plan to replace 51K resistor that has the spliced lead that you see in the picture, along with a few others where I had used film resistors with new dog-bone resistors.

Steve

[Steve Davis]

Time for the "smoke" test. I plugged it in and turned it on. Disaster strikes!!!!! After about 5 seconds, "POW" then the smoke started coming from under the chassis. I quickly pulled the plug. The input filter had exploded! Now to figure out what went wrong.

Steve

[KCMike]

Sorry to hear that. Maybe just a backward installed Ecap.

[morzh]

As long as the transformer is alive, you're ok.
There are just two major causes of electronic malfunctioning: 1) a connection where it is not expected and 2) no connection where it is expected

And the filter paper is cheap!

[Steve Davis]

I found the problem. I have found when something goes wrong, take a look at the last thing you have done, even if it seems to be totally unrelated. While working on the chassis, the rectifier tube fell out of its socket. I plugged it back in and had nearly forgotten about it. Looking at the rectifier, I noticed it was turned 90 degrees from where it should be. Apparently sometime in the past, someone had forced the tube into the socket with the wrong orientation. wallowing one of the small holes. Now the tube can be plugged in two ways with little effort. of corse, I plugged it in the wrong way. This caused one end of the filament to be connected to HV winding of the transformer. The other end of the filament was connected to the B+ line, putting high voltage AC on the filter capacitors. After correctly installing the rectifier, I replaced both filter capacitors.

Ok, "Smoke Test",  Take-Two

I powered it up again. No smoke.   I have a Sony headphone radio I keep in the shop just for checking oscillators. The radio has a digital display, so I can tell the exact frequency. I put the headphone radio on and started rocking the dial on the 19. Success! No stations, but I have an oscillator. The oscillator was running about 200KC low. I did an alignment on the oscillator and the front end and the "Super"19 began to sing!

Enough for today. More to come.

Steve

[morzh]

I saw a guy force a speaker plug into a wall outlet of 220V. The plug pitch was the same but the prongs were twice the diameter, but the guy was strong arms weak mind type and by breaking the backelite forced them in.
8 ohm speaker into 220VAC.
The speaker spewed the cone across the room and never spoke again.

[462ron]

Steve I had the same problem with the rectifier socket on my 37-116. For some reason there was a second slot in the socket which allowed the keyway on the tube to go in the wrong spot. I was lucky enough to not burn any components as I had installed a fuse in the primary of the power transformer which blew immediately! Something out of the ordinary.


Ron