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

Early Model 89 Tone control-Figured It Out, Maybe
#1

My model 89 has the tone control that is referenced in the first drawing in the following link. If I did the link correctly. The .015ufd cap and the .01ufd cap are tied together inside the tone can and are soldered to the pad (which has a lug on it) and is not grounded. The wiper switches on and off of this pad. The other end of the .01ufd cap goes to the plate of the 42 output tube and the other end of the .015ufd cap is soldered to the frame of the tone control can which is also not grounded.
http://www.philcoradio.com/tech/89evol.htm

I have my 490K resistor connected to the 7E .05 cap which ends up at the CT of the high voltage output. But there is no place for me to connect the 490K and the 7E .05 cap to the .015ufd section of the tone control unless I connect the two to the same place as the .015ufd cap which is the frame of the tone can. This is not the way the radio was wired so I don't know how the tone was working without the 7E .05 cap and the 490K resistor. Or will it work that way?

So what should I do? Redo my tone control can and make it per the 2nd drawing on the referenced link?Icon_e_confused

EDIT: I think I have this figured out without having to pull the new caps out of the already re-potted tone can. Just a matter of switching a couple of wires coming off of the caps in the tone control can and then routing and connecting them accordingly to make it match the 2nd schematic on the referenced link. I will have to ground the "Un-grounded" lug on the tone can frame and the high and low tone frequencies will be reversed when I switch from "bass" to "treble". Doesn't matter to me. It's only a two position switch anyway.

Thanks to those of you who viewed this and probably said... "What the heck is he trying to say?"

Pepper

"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th




Users browsing this thread: 2 Guest(s)
[-]
Recent Posts
The speaker table error?
G  10-1/2"       65, 76, 87, 95 Push-Pull 45's 2766 0.7 550 3200 H   10-1/2"    77, 96 Push-Pull...morzh — 09:26 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
Philco model 60
I'm also a member of MARC. Did you attend the Vintage Electronics Expo in Waterford, MI last month? That's where I got...GarySP — 07:22 PM
A Marconi model 86
Dan Double conversion is using two IF converters instead of one. This improves the image response. morzh — 07:15 PM

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

>