Federal Telephone & Radio Corp. Model 1040TB

11/3/2012 11:35:50 PMMitch

Hello everyone,

I have restored this radio and have been playing it to be sure it is working ok for the person who is going to buy it, it sounds good and picks up all of the stations where i live.

It is a low cost radio and has a tinny sound to it, although very clear on the small speaker. It does not have a tone control as seen by the schematic.

Some time ago Warren gave me a fix for this by installing a low voltage filter capacitor in the output of the radio that gave me a better, richer, tone to the output. I could experiment with the values until i got the sound that i wanted. Where would i install this capacitor?

Can some one tell me what this fix, modification, would be in the circuit of this radio (Warren, you are most welcome to post on this question as always)?

I would just like a better tone on the radio.

Most regards to all,

Mitch

11/4/2012 1:33:34 AMWarren

A cathode bypass capacitor of 20MDF at 15 volts across resistor R-9 would give the output a little more gain. The fixed tone control capacitor is C-11.

11/4/2012 8:47:12 AMLewis L.

:A cathode bypass capacitor of 20MDF at 15 volts across resistor R-9 would give the output a little more gain. The fixed tone control capacitor is C-11.

I don't have a schematic, but if the coupling cap between the first and second (output) audio stages is a .01 uFd, you could try a .1, that might increase the bass a little.
Lewis
:

11/4/2012 11:20:42 PMMitch

:A cathode bypass capacitor of 20MDF at 15 volts across resistor R-9 would give the output a little more gain. The fixed tone control capacitor is C-11.
:
Thank you all for the responses,

It would seem that low cost is low cost, for this radio.

I did install a 22 MFD capacitor across R-9, it did give more gain. C-11 changes made no change. Cap on the input made no change.

It is a very small 3" speaker, even with a 6" sub it was still a little tinny.

You all know the Forum is great and thanks for the input.

The capacitor change did improve what i needed, more gain and a stronger sound on a basic radio.

Now, I will say that my night time radio that i listen to is a 1933 Philco that i restored and has the big radio sound, I MEAN BIG SOUND, so perhaps i am spoiled.

Thank you gentlemen,

Mitch

11/4/2012 8:57:07 AMNorm Leal

Mitch

Suggestions mentioned are good for increasing low frequency response. You could try reducing high frequency response by adding capacity from the signal line to ground. This will have a similar effect as increasing low frequency response.

Most likely limiting factor is the speaker. Although you can't mount a larger speaker in this radio try connecting one.

http://www.nostalgiaair.org/PagesByModel/048/M0006048.pdf

Norm

:Hello everyone,
:
:I have restored this radio and have been playing it to be sure it is working ok for the person who is going to buy it, it sounds good and picks up all of the stations where i live.
:
:It is a low cost radio and has a tinny sound to it, although very clear on the small speaker. It does not have a tone control as seen by the schematic.
:
:Some time ago Warren gave me a fix for this by installing a low voltage filter capacitor in the output of the radio that gave me a better, richer, tone to the output. I could experiment with the values until i got the sound that i wanted. Where would i install this capacitor?
:
:Can some one tell me what this fix, modification, would be in the circuit of this radio (Warren, you are most welcome to post on this question as always)?
:
:I would just like a better tone on the radio.
:
:Most regards to all,
:
:Mitch
:
:
:

11/5/2012 3:15:23 PMEdd

Sir Mitch . . . .

I thought that units speaker was a 4 incher or possibly a 3 1/2 incher.

At any rate, if your enhancing of the bass by the addition of a cathode bypass electrolytic in the AF output stage, along with the use of a larger capacitance interstage coupling condenser, is falling short.
Just assume it to be the the small old generation speakers shortcoming.

If my problem to solve , and KNOWING that the small compact speakers being used in small speaker enclosures used adjunct to your computer create GOOD sounding audio.

I see them for a buck a pop all the time at yard sales, flea markets and Goodwill types of stores.

My last set of two was for only $3 and they were even Harmon Kardon units.

One units rear pedestal leg was broken off, but I was going to PULL the speakers . . . plus one units additional "FREE" AF amplifier.

Soooooo . . look into the use of a properly sized unit of that family / type of speakers for a replacement, and it should run circles around what you now have in the unit.

73's de Edd

You know what I did before I married ? . . . . . . . . . .
Anything I wanted to.

:Mitch
:
: Suggestions mentioned are good for increasing low frequency response. You could try reducing high frequency response by adding capacity from the signal line to ground. This will have a similar effect as increasing low frequency response.
:
: Most likely limiting factor is the speaker. Although you can't mount a larger speaker in this radio try connecting one.
:
:http://www.nostalgiaair.org/PagesByModel/048/M0006048.pdf
:
:Norm
:
::Hello everyone,
::
::I have restored this radio and have been playing it to be sure it is working ok for the person who is going to buy it, it sounds good and picks up all of the stations where i live.
::
::It is a low cost radio and has a tinny sound to it, although very clear on the small speaker. It does not have a tone control as seen by the schematic.
::
::Some time ago Warren gave me a fix for this by installing a low voltage filter capacitor in the output of the radio that gave me a better, richer, tone to the output. I could experiment with the values until i got the sound that i wanted. Where would i install this capacitor?
::
::Can some one tell me what this fix, modification, would be in the circuit of this radio (Warren, you are most welcome to post on this question as always)?
::
::I would just like a better tone on the radio.
::
::Most regards to all,
::
::Mitch
::
::
::
:
: