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

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

Philco model 18 (code 121) - HELP!

Sorry Pith and others, I missed about measuring across the filter choke. Pith, I noticed you measured the voltage from plate to ground (cathode) on the 42 output tubes and got nada. Just as a test, could you do the same DC measurement from ground to the plate of let's say the 1st IF the 78 if I read the schematic properly.
I ask this for a couple reasons. One is if you were not measuring the choke at the right place ( I would measure across the two e-caps listed as 53 and 54 on the schematic, the two positive leads) only because it is strange to have that choke open up. The other reason is that the field coil being open on the speaker would also give you no voltage on the plates of the 42 output tubes BUT if it was open would allow voltage to the plates of the other tubes in the receiver. If you don't get voltage to the other plates, certainly looks like the choke, which would kill the voltages everywhere.
I hope this makes sense! Just a double check.
If indeed the choke is open and you have no DC voltage on any of the plates of the tubes in the front end, then the resistor idea to replace the choke could become a viable long term solution if you don't want to find another choke. You would need to change the value of a couple of electrolytic caps you have changed to increase their value to add back some filtering of the DC you will have lost as the resistor does not provide the smoothing out of the DC as well as a choke.
If it indeed proves out the choke is bad, you might run a WTB in the classified section and perhaps someone has one on a parts chassis.
Good luck and check in. Your learning a lot. Again, the other people responding are a lot smarter than me. Before I go off to look for what might be an expensive part I want to make certain I have done every test to assure I'm correct.
Best of luck and post a couple pictures in the clubhouse of Ireland. One place that is on my bucket list to visit.
Jerry

A friend in need is a pest!  Bill Slee ca 1970.


Messages In This Thread
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-07-2013, 10:22 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-08-2013, 10:32 PM
RE: Philco model 18 (code 121) - HELP! - by Arran - 02-08-2013, 10:49 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-09-2013, 02:21 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-09-2013, 05:57 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-09-2013, 06:12 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-13-2013, 08:40 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-21-2013, 05:25 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 02-28-2013, 06:04 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 03-07-2013, 04:16 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 03-07-2013, 11:20 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-17-2013, 01:25 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-18-2013, 08:48 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-18-2013, 09:49 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 04-29-2013, 10:02 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 06-12-2013, 01:37 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 06-13-2013, 08:33 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 07-23-2013, 10:33 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 07-24-2013, 11:11 PM
RE: Philco model 18 (code 121) - HELP! - by jerryhawthorne - 07-25-2013, 04:35 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 08-02-2013, 05:06 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 08-21-2013, 10:26 AM
RE: Philco model 18 (code 121) - HELP! - by morzh - 12-17-2013, 10:58 AM
RE: Philco model 18 (code 121) - HELP! - by morzh - 12-19-2013, 12:47 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 12-19-2013, 08:48 PM
RE: Philco model 18 (code 121) - HELP! - by morzh - 01-17-2014, 04:05 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.

>