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

40-190 RF Problems - Need Help
#6

Pepperoni Wrote:Thanks Arran but the wax dipped mica you mention is actually two individual 370pfd caps and they read well within tolerance. Micas I usually don't replace unless they're way out of tolerance or bad or "Micamolds".

B+ is connected to the CT of the output transformer but the other two primary legs go directly to each plate of each 41 output tube. They're in push-pull configuration. This can be verified by looking at the schematic. My problem doesn't appear to be in the audio circuit but in the front end of the set. The RF section. I've already highlited two schematics verifying all of my connections. I just finished verifying all the bandswitch connections. So far I've found nothing out of place. Tomorrow I'm going to remove the pushbutton assy. and take another look at the underside of that. I'm still pretty baffled. I can't find the problem.

Pepper

How did you test the micas? Did you test them with an ESR meter or a resistance-capacitance bridge where you can put some high voltage across them? When you have replaced everything else and everything seems to be where it should be, failing micas caps is a possibility just due to process of elimination.
Regards
Arran


Messages In This Thread
40-190 RF Problems - Need Help - by Pepperoni - 10-15-2011, 03:47 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-15-2011, 08:00 PM
Re: 40-190 RF Problems - Need Help - by Arran - 10-16-2011, 10:11 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-16-2011, 11:09 PM
Re: 40-190 RF Problems - Need Help - by Arran - 10-16-2011, 11:19 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-17-2011, 12:30 PM
Re: 40-190 RF Problems - Need Help - by codefox1 - 10-17-2011, 04:19 PM
Re: 40-190 RF Problems - Need Help - by 7estatdef - 10-17-2011, 05:08 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-17-2011, 05:32 PM
Re: 40-190 RF Problems - Need Help - by Pepperoni - 10-18-2011, 01:49 PM



Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
91H Code 126 Restore
Well I'm making good progress. All the bakelite blocks have been recapped.  I found that using a heat gun and skinny ...RealRider — 02:35 PM
Philco model 60
>>and found that the field coil is bad. Should be 1140 ohms, tests at 1.1k ohms. You have one stringent crit...morzh — 02:07 PM
Philco model 60
Yes I was there. I got some real bargains there. Plus a Zenith 7G605 clipper that I have been trying to find for a fair ...Radios1340 — 01:46 PM
A Marconi model 86
I have a Stromberg, one of the early ones, seems early 30s. This is what I call a back breaker. None of the early Philc...morzh — 08:28 PM
A Marconi model 86
A backbreaker.....PaulPaul Philco322 — 08:12 PM
A Marconi model 86
>>What a behemoth! A Juggernaut.morzh — 07:47 PM
Philco 70 antenna lead
I am not sure I understood about the coils and the mush. I looked an more than one coil in 20, 70, 90, 60, Zeniths and ...morzh — 07:46 PM
A Marconi model 86
:e_biggrin: What a behemoth!  I hope the final result is as much a quality sounding example!  Keep us posted on your pro...GarySP — 07:32 PM
A Marconi model 86
I should add that the double conversion may only be used on the shortwave bands, but I haven't looked at the schematic t...Arran — 07:27 PM
Philco 70 antenna lead
Yes, that wire will not pick up much interference as routed - the RF at that level won't be affected, and if you have st...radio1 — 07:26 PM

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

>