[w4rtc]

Hi
Well I just finished stuffing the caps (black blocks) on my 16B , align the I. F. and the RF (boy that RF is hard to align correctly . The radio is a good performer but The the tone control does not have any effect except all the way clockwise which cuts the Highs. I went over this thing many many times and I know it is wired correctly the only diff is for a .9 mf I used a .82. Is this normal for the 16B??. My radio had the following .9 , two .25's and a .003 and a four poss shorting switch in the tome control circuit. What to do??
The radio has great audio but the first three position's have no effect.
Joe

[Ron Ramirez]

Hi

The tone control on Philco sets of that era were designed to cut the highs to a greater or less degree.

Hold the phone. I think you have made a mistake. The earliest 16 tone control used a 0.5 and 0.15 uF caps in a metal container, external to the tone control, and .09 and .006 uF caps inside the control. This was changed later to a bakelite block containing two .025 uF caps external to the control (part no. 7653-C), along with .09 and .003 uF caps inside the control.

I think yours should have the .09 uF inside the control along with the .003, not 0.9 uF. Also, the .25 uF caps should be .025 uF.

With cap values that high, it is no wonder the tone control is ineffective except on the last (fourth) position.

With each "click" of the control, the highs should be cut gradually more and more. The control does work as advertised with .09 and two .025 uF caps. You can use 0.1 uF to replace the .09 uF cap.

[w4rtc]

HI
Boy howdy, did I make a mistake , my control has a .09 and .003 (78) in the little box and two .025 in the bakelite block (80) . I was sorta sleepy when I wrote that comment, but this is correct . It just don't make much diff on the first three steps (clicks) the fourth cuts the highs pretty good, I guess the vol control could have a bad tap. It looks to me like the first and second "clicks" are for bass boost.. For the .09 I used a .082. I cannot find what code mine is (121 ETC.) My 16 was changing in frequency until I changed out the .0007 and 00125 (17) mica cap (28) it is o k now.
Thanks for answering
Hope you are feeling o k
Joe

[Ron Ramirez]

I'm doing well, thanks.

The change in tone is very gradual, not dramatic, with that tone control circuit. Philco later switched to a different circuit cutting three .003 uF caps in and out of the plate of the first audio tube. That tone control has more noticeable changes from high to low.

If you can find a Model 16 - Code 125 and 126 (4-band) schematic, you will see that tone control circuit. Philco also used it in the late production of the 5-band 16 sets.

[w4rtc]

Hi Ron
I found that info on the tone control. It uses three .003 caps HMMMMM I may try that on my radio. The only thing is that I like to keep these old radios as orignal as possible, but since it was used in the 16 I guess it would be O K .
Thanks Ron I'm going to bed
take care
Joe

[Ron Ramirez]

I generally try to keep mine as original as possible also, but in recent years I have taken liberties with the tone control at times. Especially with two very rusty chassis I had that some would consider too far gone to salvage - a Model 71 and a Model 89. Both now have potentiometers instead of switches for tone controls, and both have 6A7 1st detectors instead of 36 tubes.

http://www.philcoradio.com/notebook/super71.htm
http://www.philcoradio.com/notebook/super89.htm