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

40-201 now has power
#18

Radioroslyn;

Thanks for the compliments! Yes a nice BFO would be nice for alternate modulation type signals. I might do something along those lines. I have a few single gang variable air capacitors that I could use to create something for that purpose.

I discovered a minor problem earlier today. If I had the volume set at a certain level, and turned the tone control from end to end it killed the sound completely at anything past 1/2 way toward the plate circuit of the 1st. audio tube. It was not the control, verified with power off and using the ohm meter. It turned out to be another one of the .01mFd capacitors that had shorted (part item 52) which someone had installed years ago. It should have been a .006mFd in order for the tone control to work properly. I was out of .01 capacitors but had a few that I had removed from the set. I found two that were not shorted or leaky and put them in series which makes a .005mFd. I also had a 1000pFd silver mica capacitor and added that across the two in series to make a .006mFd. I took the offending shorted capacitor out of the set and installed the cludged capacitor in its place. I turned the radio back on and Presto! No more loss of audio as the tone control is turned end to end. An added plus is that it also now really does change the tone like it should.

I notice an odd popping sound as the set is warming up. It may be due to one of the audio tubes, but it goes away after the sound comes up and does not return until I turn it on from a cold start again. I hope it is not some problem developing with the field core of the speaker.

The radio sounds so good right now that I may just let it go until I find it becomes a real problem that is obvious to find. I might monitor the B+ to see if there is any fluctuation there as the radio is warming up from a cold start. That would probably show up easiest at C77 if there is an intermittent short or open happening during warm-up.

I went ahead and installed the new push-buttons on the front that I had ordered. They were loose and popped off when pushing adjacent push-buttons, so single folded layer of Scotch magic tape over the button shaft was enough material added to make the push-buttons stay on their shafts.

Joe
KC5LY


Messages In This Thread
40-201 now has power - by Joeztech - 12-23-2013, 03:45 PM
RE: 40-201 now has power - by jerryhawthorne - 12-23-2013, 04:27 PM
RE: 40-201 now has power - by Joeztech - 12-23-2013, 06:45 PM
RE: 40-201 now has power - by jerryhawthorne - 12-23-2013, 07:13 PM
RE: 40-201 now has power - by Joeztech - 12-23-2013, 08:08 PM
RE: 40-201 now has power - by codefox1 - 12-23-2013, 08:56 PM
RE: 40-201 now has power - by jontz - 12-23-2013, 09:33 PM
RE: 40-201 now has power - by Paul Philco322 - 12-23-2013, 11:11 PM
RE: 40-201 now has power - by Joeztech - 12-24-2013, 07:33 AM
RE: 40-201 now has power - by Joeztech - 12-24-2013, 07:45 AM
RE: 40-201 now has power - by hsusmann - 12-24-2013, 10:14 AM
RE: 40-201 now has power - by Joeztech - 12-24-2013, 04:53 PM
RE: 40-201 now has power - by hsusmann - 12-24-2013, 05:53 PM
RE: 40-201 now has power - by Joeztech - 12-24-2013, 08:03 PM
RE: 40-201 now has power - by hsusmann - 12-24-2013, 08:53 PM
RE: 40-201 now has power - by Joeztech - 12-24-2013, 10:54 PM
RE: 40-201 now has power - by Radioroslyn - 12-25-2013, 11:15 AM
RE: 40-201 now has power - by Joeztech - 12-25-2013, 03:34 PM
RE: 40-201 now has power - by BrendaAnnD - 12-25-2013, 06:47 PM
RE: 40-201 now has power - by Joeztech - 12-25-2013, 07:05 PM
RE: 40-201 now has power - by Joeztech - 12-26-2013, 08:15 AM
RE: 40-201 now has power - by hsusmann - 12-26-2013, 09:53 AM
RE: 40-201 now has power - by Joeztech - 12-26-2013, 11:48 AM
RE: 40-201 now has power - by hsusmann - 12-26-2013, 10:54 PM
RE: 40-201 now has power - by BrendaAnnD - 12-26-2013, 11:59 PM
RE: 40-201 now has power - by Eric Adams - 12-27-2013, 01:50 AM
RE: 40-201 now has power - by Joeztech - 12-27-2013, 07:28 AM
RE: 40-201 now has power - by Joeztech - 12-28-2013, 01:28 PM
RE: 40-201 now has power - by Joeztech - 12-28-2013, 05:36 PM
RE: 40-201 now has power - by codefox1 - 12-29-2013, 08:30 PM
RE: 40-201 now has power - by morzh - 12-29-2013, 08:42 PM
RE: 40-201 now has power - by Joeztech - 12-30-2013, 07:17 AM
RE: 40-201 now has power - by Joeztech - 12-30-2013, 07:30 AM
RE: 40-201 now has power - by Joeztech - 12-31-2013, 06:33 PM
RE: 40-201 now has power - by jerryhawthorne - 12-31-2013, 07:54 PM
RE: 40-201 now has power - by Joeztech - 02-19-2014, 08:05 PM



Users browsing this thread: 6 Guest(s)
[-]
Recent Posts
6TPZ and 5TPO Radio Help
Oh...and you have electrolytic caps there. All need to go and be replaced.morzh — 04:36 PM
6TPZ and 5TPO Radio Help
Thanks, will do.R3Sons — 01:25 PM
1930s Stewart-Warner Tombstone Radio need help identifying model number
UPDATE: I was able to pick up a signal generator on the cheap (amazingly enough) on feebay and I did an IF alignment fol...captainclock1988 — 09:53 AM
Philco 91 Schematic
Hi Rod, The resistor connects to pin 4 and the ungrounded side of block 9. From pin 9 of the RF tube to one side of ...dconant — 09:34 AM
Just got a 49-1613 need to know...everything!
I just found your post. I have this exact same model, and have had it since 1985 when I was 15 years old! I performed a ...MuzzcoVW — 09:11 AM
B&K 1077B no video
Hello Tim, I would if it's a leaky Capacitor So are all 3 of those B- voltages low then ? Sincerely Richardradiorich — 01:55 AM
B&K 1077B no video
I found a schematic and think I have the problem traced down to the minus power supply. I have very low voltages that go...TV MAN — 12:41 AM
RCA 15X
I'd try replacing the bulb first and if that doesn't do it, then change the 35Z5 and see if the problem goes away.NostalgiaRadioTime — 12:28 AM
B&K 1077B no video
Hello Tim, I have that exact unit in my shop too plus a Sencore unit there are times I like one or other !!. Sincerely...radiorich — 11:07 PM
RCA 15X
Everthing goes at once, maybe it's the cold weather, I have had 2 dial strings break and no my little RCA is having dial...Paul Philco322 — 10:26 PM

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

>