Test Equipment schematics

6/20/2002 3:00:37 PMDan Jackson

Could anyone tell me where to find schematics for old test equipment? I have a Philco tester #048 and would like to get the oscillator to work. Any help would be appreciated.

Dan

6/21/2002 11:34:06 AMJohn McPherson

Hi,
You could try the usual sources, A.g Tannenbaum, et al. But when in doubt, replace the caps, after testing all of the tubes. Once that is doen, you should get something out of it. Then comes the issue of calibrating it, and locating a calibrated reference.

:Could anyone tell me where to find schematics for old test equipment? I have a Philco tester #048 and would like to get the oscillator to work. Any help would be appreciated.
:
:Dan

6/21/2002 11:17:36 PMDan Jackson

Hi,
:You could try the usual sources, A.g Tannenbaum, et al. But when in doubt, replace the caps, after testing all of the tubes. Once that is doen, you should get something out of it. Then comes the issue of calibrating it, and locating a calibrated reference.
:
:
:
::Could anyone tell me where to find schematics for old test equipment? I have a Philco tester #048 and would like to get the oscillator to work. Any help would be appreciated.
::
::Dan

6/21/2002 11:25:07 PMDan Jackson

John,
Thank you for your responce. I tried Tannenbaum and a couple of others without success. I was hoping that Riders or another source might have it. My trouble is that the Osc. coil heats up when I applied a battery, but I couldn't find any short. I think someone might have altered the wiring many years ago by adding a choke coil. Don't know for sure. Thanks again.
Dan

:Hi,
::You could try the usual sources, A.g Tannenbaum, et al. But when in doubt, replace the caps, after testing all of the tubes. Once that is doen, you should get something out of it. Then comes the issue of calibrating it, and locating a calibrated reference.
::
::
::
:::Could anyone tell me where to find schematics for old test equipment? I have a Philco tester #048 and would like to get the oscillator to work. Any help would be appreciated.
:::
:::Dan

6/22/2002 3:58:23 PMJohn McPherson

Hi,
Philco did use those flexible resistors- Which also doubled as a fuse. They were usually rated anywhere from 2 watts on up... It may be that one was removed some time ago because it failed, or was not recognized as a resistor.

Failing anything specific, I would start to trace out the circuit, and then start comparing it to some old ARRL references for a comparable oscilator, and make/remake the oscillator along the ines of the ARRL circuit. You may find something similar in an RCA tube manual (or other manufacturer) that outines that general circuit.

:
:
:
:
:John,
:Thank you for your responce. I tried Tannenbaum and a couple of others without success. I was hoping that Riders or another source might have it. My trouble is that the Osc. coil heats up when I applied a battery, but I couldn't find any short. I think someone might have altered the wiring many years ago by adding a choke coil. Don't know for sure. Thanks again.
:Dan
:
::Hi,
:::You could try the usual sources, A.g Tannenbaum, et al. But when in doubt, replace the caps, after testing all of the tubes. Once that is doen, you should get something out of it. Then comes the issue of calibrating it, and locating a calibrated reference.
:::
:::
:::
::::Could anyone tell me where to find schematics for old test equipment? I have a Philco tester #048 and would like to get the oscillator to work. Any help would be appreciated.
::::
::::Dan

6/23/2002 5:10:28 PMBob Kulow

I have a schematic for the Philco 048 oscillator. It's in Ghirardi's Modern Radio Servicing, 1935 edition. I'll scan it and e-mail it to you.

73
Bob WA2UEH