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

Model 16 tone control
#1

I am almost finished recapping a model 16x (5 band) type 121. The tone control has two caps inbedded in the control and two in separate tin box. It is a 4 position control in position 1 a .006 mfd cap connects the plate of the 1st audio tube to ground in the next position it seems as though a .09 cap is in the circuit in the next two positions a .15 cap and a .5 cap are added to the circuit according to my schematic. The tone control had very little variation in positions 2, 3, and 4. There was no change after recapping. Is this typical? Could it be that the cap values on the schematic are not correct? The last two in particular seem a bit large for a tone control but my simple analysis would be that lowering the values would result in even less variation in tone between switch positions.

Thank you,

JT in Albany
#2

I made a mistake in that the radio is a Model 16 type 122. I also found another schematic that had cap values of .003, .025, .025 and .09. I swapped out the .006, .09, .15, and .5 called for in my original schematic and the variation in tone between switch points is much improved. Apparently, in the original setup after the .09 siwtched into the circuit the additional capacitance made little difference in terms of tonal variation. By starting from a lower base and narrowing the range of capacitance the second setup seems to hit the correct range in which the additional capacitance at each step differentiates the tone.

JT in Albany
#3

Good to hear you found the problem.

I was away all day yesterday and could not respond before now, sorry.

--
Ron Ramirez
Ferdinand IN




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Shadow Meter Bulb
Phorum members, I am trying to find the bulb # for PHILCO Shadow Meter part number 45-2180 that is from a 37-640 chassis...georgetownjohn — 06:53 PM
Philco 41-608 changer coupler
3D-printing...short of machining, of course. Or molding.morzh — 05:20 PM
Philco 41-608 changer coupler
Thanks, Morzh. That solves the issue of the rubber pieces. Now, I need to find a way to replicate the pot metal piec...alangard — 05:07 PM
12' Philco
If it is 12', either Kareem or Andre would have to jump pretty high to look at the front panel. Kareem would have an e...morzh — 01:48 PM
12' Philco
And here's a story about the tires on the truck. Same "no-stoop" guy must have installed these! Take care a...GarySP — 01:17 PM
Hickok AC51 tube tester
I think they have only shown the secondaries of the transformer. Two of them feed the rectifiers' filaments.morzh — 12:58 PM
IF can wire size and Rubber mounts?
Arran If the wire inside cans is the gauges you mentioned, the sole reason for that would be mechanical, to stiffen t...morzh — 12:56 PM
12' Philco
Rod, Yes, I know, but the Giant Philco is not around anymore either, so I go by whoever was alive fairly recently. H...morzh — 12:54 PM
Hickok AC51 tube tester
Absolutely no one is going to reverse engineer that circuit. Even the iron core is missing.RodB — 10:37 AM
IF can wire size and Rubber mounts?
Thanks to both members for your help regarding wire and tuner mtg supports. regards--Johngeorgetownjohn — 09:33 AM

[-]
Who's Online
There are currently 4660 online users. [Complete List]
» 1 Member(s) | 4659 Guest(s)
Avatar

>