Posts: 11
Threads: 5
Joined: Oct 2018
City: Burlington
State, Province, Country: Wisc
Hi All,
I've just finished restoring a Philco 40-200 and did the alignment and is working great.
Now I'm trying to adjust the push buttons and buttons 1-4 won't adjust below 1200 KHz.
The upper buttons (5-8) work well, I adjusted them 1050-1400 KHz.
Thanks
Denis R.
Posts: 7,215
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
Depends. We need to figure out which isn't tuning properly. Use a counter or another receiver to track the local oscillator frequency and see if it's tuning low enough ( it should be 455kc above the in coming signal . To receive a signal @ 560kc the osc should be running @ 1015kc). If that isn't working properly check 23 and 24 for correct tolerance. This is assuming that the switching and wiring is as it should be.
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 11
Threads: 5
Joined: Oct 2018
City: Burlington
State, Province, Country: Wisc
Hi Terry, I checked the wiring, switches and coils and all is well. Each coil is about 3.1 ohms.
Cap #24 = 181.0 pF
Cap #23 = 190.2 pF
I think both caps should be 370 pF, my schematic is not that great and hard to read.
Denis R.
Posts: 7,215
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
For a better schematic go to
http://www.audiophool.com/Philco.html Scroll down to 1940 and click on 40-195/40-200.
I'd replace those to caps w/ 370mmfd. Not have enough capacity there more than likely would be the cause of the lack of the low frequency oscillator coverage. Come to think of it my 41-300 buttons won't tune below abt 700kc. Can't get down to the Grand Ole Opry on WSM out of Nashville Tenn.@ 650. I should have a look at mine.
We are Hams we can fix anything!!! [Image:
http://philcoradio.com/phorum/images/smi...wisted.gif]
de N3GTE
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
(This post was last modified: 10-30-2018, 08:41 AM by
Radioroslyn.)
Posts: 11
Threads: 5
Joined: Oct 2018
City: Burlington
State, Province, Country: Wisc
Hi Terry,
I replaced both caps with 370 pF caps and now I'm am able to tune through the whole BC band.
Thanks a lot for your help.
Denis R.
Posts: 619
Threads: 42
Joined: Mar 2017
City: Gap Mills Wv 24941
is this a safe plugin to download in order to get the document you posted Terry?
>>>>>>>>LizardTech DjVu browser plug-in
also,,, never seen a skinny domino cap like the one top center of your underside of the chassis!
(This post was last modified: 10-31-2018, 08:26 AM by
jcassity.)
Posts: 7,215
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
Been using it for yrs and haven't had an issue.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 4,612
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
I don't know how the pushbuttons are designed in the 40-200, but in some sets it's quite normal for there to be a range for each pushbutton,
so the lower ones won't tune in anything above a certain frequency, whilst the upper ones won't tune bellow a certain frequency. These are the banks that have an oscillator coil for each button, with a slug, and a trimmer, and they are electrically switched in and out of the front end. Some Philcos don't use this setup, they switch in a trimmer, and or a padder for each button rather then a coil, in which case each button should work across the dial.
Regards
Arran
