The PHILCO Phorum
Philco 620 - Printable Version

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+--- Thread: Philco 620 (/showthread.php?tid=21313)

Pages: 1 2

RE: Philco 620 - Neo6425 - 05-14-2020

Thanks for the kind words about the chassis.
I think I was very lucky finding this radio practically in my backyard.
So far I am really enjoying myself with this project. 
Here's my next question: Restoration or Repair? 
I think I really need to decide this before going forward.
Do I just get this radio working or do I try to restore it to look and play like it did back in the day?
I'm still just getting my head around these dodgy things called bakelites and where do I find vintage parts? (I tried to find a 30-2079 Electrolytic Cap, no luck.)
Anyone have any thoughts about this to share with a first-timer?

RE: Philco 620 - GarySP - 05-14-2020

If it were my radio, full restoration without a second thought! At bare minimum new caps and resistors. You can't trust 85 year old components, no matter how good they seem to look. Many sites are available for replacement components on the net and other outlets. You might want to also look into joining any local radio clubs for information sources. You found this PHORUM, you can also find the parts! Take your time, be meticulous, and above all... have fun!
Take care, and BE HEALTHY! Gary

RE: Philco 620 - Radioroslyn - 05-14-2020

The bakelites and eletrolytics get rebuilt by you.
It's not difficult and will render a very original look when done properly.
Here's a good source caps and such. http://www.tuberadios.com/ He's closed now but should be open tomorrow as per his site.
GL

RE: Philco 620 - morzh - 05-14-2020

Neo,

With these radios there is no "repair". Even if you sub the backelites with yellow capacitors without restuffing them, it is still a restoration, just not as elaborate.
Repair is done to a modern equipment.
An 80 year old radio is restored.
The degree of suffering is up to you, myself I restuff the caps and try to keep as many resistors as possible, but won't give another thought to puting a modern resistor inside. They just don't look as bad as yellow caps.
Then again, Steve makes faithful copies of original dogbones.
Some folks even overmold the modern resistors making it even more time consuming.

RE: Philco 620 - radiorich - 05-17-2020

hello morzh,
very well put and yes I have some repo resistors I have not used them yet but will be
I am going to work on my philco 60

RE: Philco 620 - Radioroslyn - 05-17-2020

Welcome to the Phroum Neo6425,

>I'd like to bench test this speaker. How would I go about doing that?
Testing the fc and the primary of the output transformer is good. If the fc is open it's time to find a replacement spkr. Opt can be  replaced separately.
One other important test is to GENTLY press on the paper cone on either sides of the spider (the round thingy @ the center). The cone should move in and out freely with any roughness. If there is roughness this can be the cause of distortion @ low volume.
In terms of caps I took a few minutes to peruse the parts list and this is what I came up with. All values are in Mfd unless otherwise noted. Ecaps are 450v, mylars 630v, and mica 500v. The mylars and micas may not need to be this high of a voltage rating depending on the circuit but this is the common rating.
1 .25
1 .3 (this is not a standard value so it will take a couple of caps in parallel to equal .3)
1 .003
2 10 eletrolytics
1 22 eletrolytic
2 .015 (X-Y type if you like)
2 .15
5 .02
5 .1
2 .05
3  110mmfd (100 is fine)
I would make the suggestion that it would be more simplistic to go stage by stage and would start at the lower right end of the schematic. That would be the power supply section. There's about 6 caps that need to replaced in that section. Tip there are three cardboard covers on the two eletrolytic cap (cans) don't lose or destroy them you'll need them latter.
Thank to Nathan here's a little bonus for your 620.  https://philcoradio.com/phorum/showthread.php?tid=17820

GL on you new adventure!
ps you said you liked to read!

RE: Philco 620 - Neo6425 - 05-24-2020

Quote:Welcome Neo6425! I have to tip my hat to you! That is one tight chassis to be attacking as a "first restoration". When you get through that one you should have no problem with most any other radio. You have a good bunch of guys here ready to offer any advice you may need. Take care, and BE HEALTHY! Gary
Please do not tip your hat yet Gary! 

I am just beginning to better understand what you meant when you commented "That is one tight chassis to be attacking as a first restoration".
Be well and thank for the encouragement!

RE: Philco 620 - Neo6425 - 05-24-2020

Here's an update I removed Replacement part number 66 (Condenser .3Mfd. Bakelite Block - Part# 6287 DU)
[Image: http://www.ispdi.com/Philco/images/Bakelie2.jpg]

and did my best to remove its insides.

[Image: http://www.ispdi.com/Philco/images/bakelite3.jpg]and noticed two terminals are wired together (Top terminals on the left in photo).
[Image: http://www.ispdi.com/Philco/images/bakeliteTop.jpg]
So when restuff this with new .3Mfd caps I am keeping this the same, wired in series. Is that correct?
[Image: http://www.ispdi.com/Philco/images/BakeliteNo1.jpg]

RE: Philco 620 - Neo6425 - 05-24-2020

Here's an other update I removed Replacement part number 67 (Condenser 8Mfd & 8Mfd Electrolytic - Part #30-2079)
[Image: http://www.ispdi.com/Philco/images/30-2079.jpg]
Is there a way I can use the can and restuff it with new caps? Similar to what I was told to do with Bakelites?
If not, what is the best way to proceed?

RE: Philco 620 - morzh - 05-24-2020

There are a few topics on restuffing cans.
Makes no sense to repeat the whole thing, but just do search or maybe someone has the links.
And, yes, we do restuff them.

RE: Philco 620 - LarryFS - 05-24-2020

The bakelite block reference I have shows 6287DU with two .15 mfd caps.  See attachment.  The wiring diagram is at top right.  They are not in series.

RE: Philco 620 - Neo6425 - 05-31-2020

My work on this radio is going slow, but for good reason and that's because it's my first try at restoring a radio.
Today if cleaned out a tube capacitor 30-2079.
[Image: http://www.ispdi.com/Philco/images/30-2079.jpg]
[Image: http://www.ispdi.com/Philco/images/30-2079extract1.jpg]
[Image: http://www.ispdi.com/Philco/images/302079extract.jpg]
and now I am prepping the can to be re-stuffed.