Zenith model 1203 "Tombstone" radio, (1938 I think)

I'm helping a friend with this. I was over to his house the other night and he was showing me this beautiful old console radio. He told me that he had paid someone to restore it some years ago. He said that among other things they recapped it. The radio sounds great with a surprisingly really hot front end. The only problem is that the volume will only go down so far. In looking at the schematic as I had feared the volume control R12 is a 2 Meg ohm part and looks like a tapped control with four connections on it. Where exactly they'd tapped that thing is anyone's guess.

We haven't pulled the chassis yet but I'll bet that either the control is bad or some homyok changed it, either eliminating the tap or Rube Goldberg'd
another one.

From the sound of it somehow that wiper, which goes through a cap to the
control grid of the 1st audio is not seeing ground when the control is
turned fully CCW.

If I need to I'm sure that I'll be able to come up with a control in my junk box with an audio taper somewhere between 500K and 2 Meg that would work, however the question is that tap. Can anyone venture a guess as to how far up from the low side of the wafer, (or down from the high side of the wafer) that tap would be? Thanks, Lenny

 

On Tuesday, May 27, 2014 9:31:51 PM UTC-4, captainvi...@gmail.com wrote:

I'm helping a friend with this. I was over to his house the other night and he was showing me this beautiful old console radio. He told me that he had paid someone to restore it some years ago. He said that among other things they recapped it. The radio sounds great with a surprisingly really hot front end. The only problem is that the volume will only go down so far. In looking at the schematic as I had feared the volume control R12 is a 2 Meg ohm part and looks like a tapped control with four connections on it. Where exactly they'd tapped that thing is anyone's guess.



We haven't pulled the chassis yet but I'll bet that either the control is bad or some homyok changed it, either eliminating the tap or Rube Goldberg'd

another one.



From the sound of it somehow that wiper, which goes through a cap to the

control grid of the 1st audio is not seeing ground when the control is

turned fully CCW.



If I need to I'm sure that I'll be able to come up with a control in my junk box with an audio taper somewhere between 500K and 2 Meg that would work, however the question is that tap. Can anyone venture a guess as to how far up from the low side of the wafer, (or down from the high side of the wafer) that tap would be? Thanks, Lenny

One end of the pot,(it seems like it must be the low side) looks like it does go through a capacitor then through what I think is a tone switch and then through a small value of a multi section resistor to ground. I wonder if that section of the resistor was open if that could cause my problem? Lenny

 

[Michael Black]

On Tue, 27 May 2014, captainvideo462009@gmail.com wrote:

I'm helping a friend with this. I was over to his house the other night
and he was showing me this beautiful old console radio. He told me that
he had paid someone to restore it some years ago. He said that among
other things they recapped it. The radio sounds great with a
surprisingly really hot front end. The only problem is that the volume
will only go down so far. In looking at the schematic as I had feared
the volume control R12 is a 2 Meg ohm part and looks like a tapped
control with four connections on it. Where exactly they'd tapped that
thing is anyone's guess.

Wasn't the tap there for a capacitor to ground, acting as a loudness
control?

If so, you'll just get different audio response at low volume, the radio
will work without it.

Michael

 

[amdx]

On 5/27/2014 8:31 PM, captainvideo462009@gmail.com wrote:

I'm helping a friend with this. I was over to his house the other night and he was showing me this beautiful old console radio. He told me that he had paid someone to restore it some years ago. He said that among other things they recapped it. The radio sounds great with a surprisingly really hot front end. The only problem is that the volume will only go down so far. In looking at the schematic as I had feared the volume control R12 is a 2 Meg ohm part and looks like a tapped control with four connections on it. Where exactly they'd tapped that thing is anyone's guess.

We haven't pulled the chassis yet but I'll bet that either the control is bad or some homyok changed it, either eliminating the tap or Rube Goldberg'd
another one.

From the sound of it somehow that wiper, which goes through a cap to the
control grid of the 1st audio is not seeing ground when the control is
turned fully CCW.

If I need to I'm sure that I'll be able to come up with a control in my junk box with an audio taper somewhere between 500K and 2 Meg that would work, however the question is that tap. Can anyone venture a guess as to how far up from the low side of the wafer, (or down from the high side of the wafer) that tap would be? Thanks, Lenny

If you go to this Antique Radio forum, there are many there that will
have the info you need. You will need to sign up to post, but it is
harmless. Very good forum! It covers more than antique radios.
http://www.antiqueradios.com/forums/index.php

Mikek

 

[RobertMacy]

On Wed, 28 May 2014 04:56:29 -0700, amdx <nojunk@knology.net> wrote:

...snip....
If you go to this Antique Radio forum, there are many there that will
have the info you need. You will need to sign up to post, but it is
harmless. Very good forum! It covers more than antique radios.
http://www.antiqueradios.com/forums/index.php

Mikek

Thanks for that URL! I still have the FIRST radio I ever fixed, one of
those 5 band console pieces of furniture. So it's good to know I have a
place to go ask for help to keep it a bit like it was made. ...right now
there's a 1 inch hole cut in the speaker [had to] but you know those old
speakers. You could nibble away at tears and they still worked pretty
well. I always hated the bass boost sound, but my grandfather was so used
to that sound that he asked to borrow the radio and kept it for years
until his passing. He loved his 'farm reports' news stations. Never liked
listening to them through a modern sound system.