Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12, 2025) x

Thread Closed

Philco 366 problem with filter choke
#3

I agree with Ron on all points. There is a chance if you remove and open up the shorted choke, you may find the short if it is in the first few layers of the winding. The short was was most likely caused by the failure of one of the ancient electrolytics, which at the time were very expensive, more so than a delicate choke. If you can fix it, and get at least 50-75% of the winding back in service, you will be good to go. I once used the primary winding of an output transformer from a junk portable using a 3V4 or 3S4 which had a really large impedance to substitute for a smoothing choke (do not connect the secondary winding to anything,) and upped the values of the filter capacitors, and the d**n thing worked like a charm. Physically about the same size, and it'd take a real nit picker to find out that is what I did.

Don't try any really large value capacitors as they would burden the rectifier, and possible cause it to fail, or worse yet, cause a problem with the power transformer. Ron's suggestion of a 22 mfd is appropriate for the first part of the pi filter, you could do a 33 or 4o mfd after the 2200 ohm resistor and still be OK.

You can use the tool from the following web site to approximate what will happen. Remember the 80 morphed into a 5Y3, and so on. It's free, and really pretty good.

http://www.duncanamps.com/psud2/index.htm

Best of luck!


Messages In This Thread
Philco 366 problem with filter choke - by Guest - 03-22-2009, 12:32 PM
Re: Philco 366 problem with filter choke - by codefox1 - 03-22-2009, 03:55 PM
Re: Philco 366 problem with filter choke - by Guest - 03-23-2009, 12:34 AM
Re: Philco 366 problem with filter choke - by Guest - 03-28-2009, 01:42 AM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 71 Code 125
Hello,  I am in need of a schematic for this radio. Mine has the three separate circular tube shields and a shadow me...dconant — 08:06 AM
Stromberg Carlson 1500 Squeal
And life just keeps getting more complicated.dconant — 07:57 AM
54C Complete Teardown/Rebuild
Hello Roy, here is this one sincerely Richardradiorich — 12:45 AM
54C Complete Teardown/Rebuild
Richard, Had grabbed it already but thank you just the same.  I find myself wanting to find some way to block out the...glyphmon — 12:03 AM
54C Complete Teardown/Rebuild
Hello roy, here is a link to the schematic . Sincerely Richardradiorich — 11:54 PM
54C Complete Teardown/Rebuild
Richard, The Silvertone 2014 also is a transformerless set, so I am incorporating a 1:1 600 ohm audio isolation transfo...glyphmon — 11:37 PM
Preliminary work on wife's Silvertone 2014
Did an alignment today which was interesting.  IF alignment went great, almost all was already spot-on.  Adjusting on th...glyphmon — 11:35 PM
54C Complete Teardown/Rebuild
The main problem with adding a Bluetooth input is that this set lacks a traditional power transformer to isolate it from...radiorich — 11:19 PM
54C Cabinet Refinish
I started stripping this cabinet before it got super chilly out because I knew I wasn't going to be able to work on ...glyphmon — 11:18 PM
54C Complete Teardown/Rebuild
While I'm waiting to wrap up the final steps on my wife's Silvertone 2014, I started disassembly on the next project.  O...glyphmon — 11:07 PM

[-]
Who's Online
There are currently 1387 online users. [Complete List]
» 2 Member(s) | 1385 Guest(s)
AvatarAvatar

>