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

philco model 47-1230 console Need Help
#5

Victor;

Is the transformer an original equipment type? In my 40-201, it had been replaced by an after-market substitution. I believe all the Philco transformers had their actual part number stamped into the metal or somehow written on it to identify it. The replacement in my radio had significant ohm differences from CT to either end, yet it seems to work OK after recapping and phase splitter resistor replacements. Someone pointed out that the main issue is that the two halves of the primary windings have the same inductance value, whether or not the actual DC resistance is the same. That said, I think the plate voltages going to the two push-pull output tubes should be pretty nearly equal. So should the screen grid voltages. One thing that might make the voltages different to some extent would be if one or the other tube had a leaky coupling capacitor going to its grid.

The schematic referenced above shows that one side of the transformer should measure about 280 ohms from the CT and the other should read about 310 ohms from CT or about 590 ohms plate to plate of the two 6V6GT output tubes. The cathodes of both output tubes are tied to ground and the screen grids and the plate circuits to the two tubes both are tied to the same B+ source. If one of the tubes had shorted its plate to the suppressor grid/cathode circuit it could have burned 1/2 of the winding in the transformer. Do some checking with a volt meter and let us know the voltages you see on cathodes, grids, screen grids and plates of the two tubes. Make sure that there is -16VDC at the grids of both output tubes.

Joe


Messages In This Thread
RE: philco model 47-1230 console Need Help - by Joeztech - 01-05-2014, 05:08 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 573 online users. [Complete List]
» 2 Member(s) | 571 Guest(s)
AvatarAvatar

>