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

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

Model 84 late buzz( 1935 run)
#5

Hi Bruce,

I am looking at the pic. Seems that the 2 filter caps are sharing a common negative. That common negative appears to be connected to a non-grounded pin of the AC power input filter cap. The common negative of the filter caps should connect to the center tap of the HV winding (rectifier plate winding) of the power transformer. A 325 Ohm resistor connects this center tap to ground. this resistor is bypassed by a 0.015uFcap. In addition, the values of these filter caps should be higher. The schematic states 8uF and 4uF. You can go a little higher. It appears that one of these caps in only 1uF unless a number is covered or backed out

Hope I am right. Hope this helps.

"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis

Best Regards, 

MrFixr55


Messages In This Thread
Model 84 late buzz( 1935 run) - by Bruce - 03-04-2025, 10:06 AM
RE: Model 84 late buzz( 1935 run) - by morzh - 03-04-2025, 10:25 AM
RE: Model 84 late buzz( 1935 run) - by Bruce - 03-06-2025, 08:22 AM
RE: Model 84 late buzz( 1935 run) - by morzh - 03-06-2025, 09:05 AM
RE: Model 84 late buzz( 1935 run) - by MrFixr55 - 7 hours ago



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Philco 49-1040
No fine tuning! That's a new one on me, never seen that beforeMuzzcoVW — 06:39 AM
[split] New member...
As you might have already surmised, I’m not sure of anything. You raise a good question and your pic gives it credibilit...HowardWoodard — 02:08 AM
[split] New member...
Are you sure that the flange at the end of the shaft isn't just completely worn off or bent over causing the indentation...rfeenstra — 11:03 PM
Model 84 late buzz( 1935 run)
Hi Bruce, I am looking at the pic. Seems that the 2 filter caps are sharing a common negative. That common negativ...MrFixr55 — 10:55 PM
[split] New member...
I think you’re right about everything. A couple years later they were machining it out of a single piece of metal. Still...HowardWoodard — 10:49 PM
[split] New member...
Looking at the drawing, the ball should be glued well, as it seems that it rolling against the 3 other balls is what pro...morzh — 10:29 PM
[split] New member...
It is concave and the balls rests in it about 25%-33% of the circumference of the ball.  I'm just contemplating which wo...HowardWoodard — 09:03 PM
38-690 Gill Cloth
Thinking of it, the cloth on both 37-690 and 38-690 is flat, no pattern, not embossed, pinkish-yellowish type. If you h...morzh — 08:44 PM
38-690 Gill Cloth
thank youtargeteye — 08:38 PM
[split] New member...
I think that's the one I have in Philco 60, which I have recently fixed. The last robodial radio repair (38-690) happen...morzh — 04:58 PM

[-]
Who's Online
There are currently 2962 online users. [Complete List]
» 1 Member(s) | 2961 Guest(s)
Avatar

>