The PHILCO Phorum
Philco 15DX restoration - Printable Version

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+--- Thread: Philco 15DX restoration (/showthread.php?tid=4706)

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RE: Philco 15DX restoration - Radioguy52 - 07-28-2012

Jerry: Thanks for the idea.. no guts no glory!! I used your method and changed all of the caps. It improved my band width on the upper 570k end some.. Not sure why. I did note the 1Uf cap was reading 1.6Uf.. Now I still need to work on alignment if I can figure that out, and sort out the tuner eye feature. It lights up and changes width when I select LD vs Local switch but not much in the middle .

RE: Philco 15DX restoration - jerryhawthorne - 07-28-2012

Radio Guy, nice job! Bob, sorry this was directed a little from your original post, but nice to have someone doing something along the same lines. Still watching how your doing. Another week on a different project and on to my 111 and it's big cap can. Nice to see Radio Guy dive in and lack fear!

Jerry

PS: Radio Guy, time to start a new thread on any other problems you have with your unit. Just go to the electronic restoration forum and hit new topic. Many will be able to help you with your eye tube issues and any others you have. JH

RE: Philco 15DX restoration - jerryhawthorne - 08-21-2012

Bandersen, awaiting any more updates on your restoration. Where are you?
Jerry

RE: Philco 15DX restoration - Bob Andersen - 08-21-2012

I'm here, I just don't have any updates on this project. I've been too busy with work and other projects. Don't worry , I'll be back at it soon.

RE: Philco 15DX restoration - Bob Andersen - 01-01-2013

After a long hiatus, I'm finally back to working on this set Icon_smile

I carefully traced out the wiring for the replacement Wheeler speakers and hooked them up.
[Image: http://farm9.staticflickr.com/8355/8336098774_0dacdb7882_c.jpg]

Then, I populated all the tube sockets and flicked the switch.
It's alive Icon_thumbup Plenty of volume, but it's not as sensitive as I expected. Also, the shadow meter isn't working very well. I'm not sure about the condition of all the tubes so I'll test them before moving on the checking voltages.
[Image: http://farm9.staticflickr.com/8081/8336099554_04ac1c1655_c.jpg]

RE: Philco 15DX restoration - codefox1 - 01-02-2013

If all else fails, these guys probably have the bulb you need:

http://www.bulbman.com/

RE: Philco 15DX restoration - Bob Andersen - 01-02-2013

Another problem I'm having is that after playing about 3-5 minutes, the volume drops off significantly. All tube tubes tested fine so I checked all the voltages.
Most are fine but the grid bias on the 1st and 2nd audio are 10 times what they should be. 0.4 => 5 and 0.2 => 5.

The RF tubes is a bit off as well, but not nearly as much.

I do have a few original dogbones left in the set because they test fine. I'm thinking they may drift off value as the set warms up so I'll try replacing them next.

[Image: http://farm9.staticflickr.com/8504/8339095169_6e045ba21b_b.jpg]

RE: Philco 15DX restoration - jerryhawthorne - 01-02-2013

Had the same problem on my Philco 90. After doing a little monitoring with my scope and generator, it was not in the amp section but in the front end. Well tubes tested good, caps were changed and resistors checked fine. I just replaced the resistors and all was well. Can't tell you the one that was the problem but seems as was suggested sometimes the old ones work well until a little heat. Just a suggestion.
Jerry

RE: Philco 15DX restoration - TA Forbes - 01-02-2013

I found that to be true with the model 111 and model 112s I have done. The resistors, especially the higher wattage ones, are un-reliable and should be closely scrutinized. I started automatically replacing them if they were over 10%.

I am still cleaning/polishing the chassis components on my model 15, but when I do start the electronics I will do the same.

Come to think of it, I need to get some pics of the progress on the 15 here on the Phorum.

RE: Philco 15DX restoration - Bob Andersen - 01-03-2013

Well, I replaced every resistor and it made no difference. Next, I tried swapping around the 39/44 tubes and it seems to be making a difference even though they all test well into the good range on my Hickok 600A. I'll go digging for some spares I think I have stashed away somewhere.

RE: Philco 15DX restoration - jerryhawthorne - 01-03-2013

Bob, I did also replace one tested good tube when I did the resistor change at the same time. Not certain which did it but not being that curious I just said "It Works". Should probably tried the other tube but at that point, just happy. Might sell that tube to someone else, after all, it tested good.Icon_biggrin

Jerry

RE: Philco 15DX restoration - Arran - 01-03-2013

Maybe it's a bad solder joint acting up after the set runs for a while? I would start by re-soldering the grid caps since they are obviously exposed to heat and mechanical stress, don't forget the grid lead and the clip as well.
Regards
Arran

RE: Philco 15DX restoration - TA Forbes - 01-03-2013

The 36 tube can also be the problem. I have had them test good but refuse to oscillate.

RE: Philco 15DX restoration - Bob Andersen - 01-03-2013

Now that I've swapped around the tubes a few times I can't replicate the problem. I'm leaning towards the problem being a bad solder joint or dirty tube socket. I did a quick alignment by ear and it's playing quite well now Icon_smile

Next up I'm going to unmount the tuning cap assembly and replace the rotted mounts. I'll clean up the chassis more while I have it apart too. Once I get it all cleaned and reassembled, I'll do a proper alignment.

RE: Philco 15DX restoration - jerryhawthorne - 01-03-2013

Great news Bob and congrats.Icon_clap

Jerry