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

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

41-240 Power Transformer
#5

Kenneth is right.  Unless its been serviced recently the electrolytic caps, paper caps and some resistors will need replacement before you power it up again.

You can find a free schematic here: http://www.nostalgiaair.org/pagesbymodel...013402.pdf

and a clearer one here: http://www.audiophool.com/Philco.html  (you need a djvu reader for this one)

or a very clear one from Chuck for a few bucks: http://www.philcorepairbench.com/schematics.htm

The rubber wiring in this model will likely be bad and need replacement see: http://www.philcoradio.com/phorum/showth...?tid=14959

Caps at #52 should be Y2 safety caps, See: http://www.justradios.com/safetytips.html

The power transformer can be checked to some extent by checking the windings for their resistance (radio should be unplugged).  In the schematic below you see the power transformer.  If you place your ohm meter leads on the rectifier plate sockets (take the tube out) you should see something around 620 ohms.  Keep one lead on one of the plate sockets and place the other on the chassis.  You should see an open circuit (infinite resistance). If you see that, the secondary HV windings are good and there is no short to the chassis.  Similarly, you can check the primary windings by putting the ohm meter leads on the plug (with the set on-off switch in the on position).  You should see something around 13 ohms.  The filament secondary windings can be checked in a similar fashion although that will appear almost as a dead short since its resistance is only 0.2 ohms.  If these measurements all look good it could have been a short someplace else in the radio caused the power xformer to heat up.  They can have some wax/tar melt out and still function but its best to figure out why that happened.  Others on the Phorum are much better trouble shooters than I am but this is a pretty basic first look.  

[Image: https://dl.dropboxusercontent.com/u/5462...former.jpg]


Messages In This Thread
41-240 Power Transformer - by ccbaker13 - 10-23-2016, 04:11 PM
RE: 41-240 Power Transformer - by ccbaker13 - 10-23-2016, 08:42 PM
RE: 41-240 Power Transformer - by klondike98 - 10-23-2016, 09:04 PM
RE: 41-240 Power Transformer - by Radioroslyn - 10-23-2016, 09:31 PM
RE: 41-240 Power Transformer - by ccbaker13 - 10-24-2016, 07:13 AM
RE: 41-240 Power Transformer - by ccbaker13 - 10-24-2016, 09:34 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Model 70 Cabinet Trim
musar , Well if you have any more questions feel free to post away . Sincerely Richardradiorich — 08:56 PM
Model 70 Cabinet Trim
Although I have not made any cabinets or cabinet parts for a couple of years, I still have some parts left over, includi...Steve Davis — 06:26 PM
philcorepairbench.com - shadow-meter
Thanks Ron.fenbach — 02:43 PM
Model 70 Cabinet Trim
Thank you, Gary. Before making my original post, I had clicked on "Steve Davis Cabinets" only to find that it...musar — 02:25 PM
philco predicta
Welcome to the Phorum, cgl18! I am not your resource for television repair, but lots of friendly help is available here...GarySP — 02:12 PM
Model 70 Cabinet Trim
Welcome to the Phorum, musar! You can send Steve Davis a private message (PM). The site is at the top of the Home page...GarySP — 02:09 PM
Model 70 Cabinet Trim
How do I contact him? The only contact information for him I could find when searching online was a telephone number th...musar — 10:38 AM
philco predicta
Hello, good afternoon, I would like to ask what the possible problem could be if I don't have an image on the screen. I ...cgl18 — 10:19 AM
Philco model 38 code 121 not receiving signal.
So one last question before I finish this radio. Regarding the speaker and output transformer. I salvaged the original o...Stormlord5500 — 09:31 AM
462ron
It’s on the bottom of the homepage of our Philcoradio.com homepage! Ron462ron — 07:20 AM

[-]
Who's Online
There are currently no members online.

>