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

48-475 signal injection
#9

Now I'm baffled. Looking at the schematic, I get a strong audio signal on pin 3 of the 7C6. I also get a strong signal on the volume control, as well as the left side if R205. I get a very weak signal on the right side of R205.

I get no signal from the plate of the 7C6, and therefore to the input grid of the 7B5.

So how is this strong signal getting to the speaker? What path through what components could it be taking?


Messages In This Thread
48-475 signal injection - by Patrick - 09-27-2015, 02:34 PM
RE: 48-475 signal injection - by Patrick - 09-29-2015, 02:47 PM
RE: 48-475 signal injection - by Radioroslyn - 09-29-2015, 06:11 PM
RE: 48-475 signal injection - by Patrick - 09-29-2015, 06:41 PM
RE: 48-475 signal injection - by Raleigh - 09-29-2015, 07:53 PM
RE: 48-475 signal injection - by Patrick - 09-29-2015, 08:54 PM
RE: 48-475 signal injection - by Raleigh - 10-02-2015, 10:27 PM
RE: 48-475 signal injection - by Patrick - 10-04-2015, 01:00 AM
RE: 48-475 signal injection - by Patrick - 10-09-2015, 02:44 PM
RE: 48-475 signal injection - by Patrick - 10-09-2015, 01:23 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
My Philco 37-116 Restore
Measuring from center tap like the tube voltages show. Cap 127 is isolated from ground. Cap 127 shown in upper left of p...dconant — 08:05 AM
My Philco 37-116 Restore
Are you measuring relative to the centertap or the GND?morzh — 11:57 PM
Philco 610B oscillator wiring
Still not clear on the wiring interface between the 6A7 and oscillator. After refering to the available schematics and s...Tubester — 07:18 PM
Refinishing Ideas
My 37-116 code 121 is the best sounding radio i have...a daily driver. Since we are talking about "changes". ...poulsbobill — 07:18 PM
My Philco 37-116 Restore
Hello, I finally got brave enough to take the cans off the Expander Unit. Got the grid cap wires replaced and back toget...dconant — 06:50 PM
Zenith H725
I got into the first AM IF can today, and found its mica was cracked. Amazing that it was still working. This one makes ...EdHolland — 06:10 PM
Philco model #20
AHH HA , I got it and can’t thank you fellows enough , when I changed the capacitors I took the advice and did not unsol...onlyrick — 02:24 PM
Zenith H725
Hello Ed, yes, I like letting projects run for few days to make sure they don't start acting up . Sincerely Richardradiorich — 01:03 PM
Philco 46-480 Electronic Restoration
I am almost finished with this restoration. All which remains is the power transformer. I cleaned it up some time ago, b...jrblasde — 12:41 PM
Philco model #20
I seem to recall in some TRF sets there being a Local/Distance toggle switch that removes the B+ from the first 24 rf tu...RodB — 09:46 AM

[-]
Who's Online
There are currently 785 online users. [Complete List]
» 1 Member(s) | 784 Guest(s)
Avatar

>