Posts: 88
Threads: 35
Joined: Dec 2013
City: Tulsa, OK
Posts: 990
Threads: 40
Joined: Feb 2015
City: Roseville, MN
You can probably use the body-end-dot scheme on these. There was a doggone transition period where the BED was used before the bands became standard. So, if the body is orange, the end band black and middle band red you have a 3000 ohm resistor.
Posts: 7,285
Threads: 268
Joined: Dec 2009
City: Roslyn Pa
They aren't 4 banded but bed resistors. The the at the top of the first page the predominant color (body) is purple =7. End is black= 0. And middle band (dot) orange =3. Totaling 7 and 4 zeros 70,000 or 70K. The tricky ones are ones that the first two numbers are the same. If you look down 3 resistors below the 70K there's one that just has two colors. First time I saw one of those I didn't take it at face value but scratched my head thought what the heck?? But it's white white yellow= 99K. Nowdays it's replaced with a 100K.
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
(This post was last modified: 11-15-2020, 10:09 AM by
Radioroslyn.)
Posts: 88
Threads: 35
Joined: Dec 2013
City: Tulsa, OK
so the one in the second photo should be 3k ohms
Posts: 990
Threads: 40
Joined: Feb 2015
City: Roseville, MN
Looks like it. Body is orange, end looks black and center band looks red. That's 3K.
Posts: 1,874
Threads: 212
Joined: May 2015
City: Seattle
State, Province, Country: WA
For the factory service info have a look in the Philco Library - Service Info section:
https://philcoradio.com/library/index.php/service-info/
Here is a direct link to the service bulletin for 38-116 (Code 125):
https://philcoradio.com/library/download...20286A.pdf
Posts: 71
Threads: 5
Joined: Nov 2005
City: Beaver Falls
State, Province, Country: Pennsylvania
Those are the IRC "BT" type insulated resistors. Philco used them heavily, but they turn up in other makes as well, along with early audio equipment. They are read the same as the dogbone type, except that a band is used instead of a dot (some early ones did use a dot). Many times, they are still OK.
Tim KA3JRT