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help with an old repair - 40-201 chassis
#31

(08-18-2015, 07:59 PM)klondike98 Wrote:  Is it grounded through the mounting rivet or bolt that holds the resistor to the chassis?  Cap #77 is probably grounded through its mounting on the chassis.

Ahhh that could be it! - that would be a common ground. 
#32

next question - I have a 40-201 -

clearly shown on the wiring schematic is a a 7C6 for model 40-200 only. I am supposed to have a 7A6, but the tube is a 7C6 in the socket. Is this ok? Tracing the wires it appears that this socket is in fact the 7C6 socket in the 7A6 location????? The schematic says that this is the location of 7C6 and use of 7C6 in the 40-195 model only.
#33

Check out the notes on the bottom of the schematic, under the coil diagrams. It should be pretty clear that the 40-195 code 121 and 40-201 code 122 use the same chassis, so whatever the schematic says about the 40-195 is the same as your radio.

They don't say "the same." They say "similar." I have a hunch they probably mean "the same" except for model and code number stamps, serial number series, and other non-technical things that would distinguish one chassis model from an otherwise identical assembly destined for the other model.

It does clearly state that "Service information for Model 40-201, Code 122 is the same as that for the Model 40-195."

Note that the schematic diagram shows connections for the 7A6 are in dotted lines. The note says the dotted connections apply to 40-200 only. For service purposes you have a 40-195, so the 7A6 is not in your radio. The 40-201 should only have 2 tubes in the row next to the IF coil #39.

John Honeycutt
#34

clearly it's not clear to me. Could it be that I am simply overwhelmed or losing some of my marbles in the 40's? Not so fun to ponder possibly, but thanks for the clarity -

rereading the schematic I see that the "location of 7C6 tube in the 40-195" is the same location as the 40-201, hence the understanding now that I am no further "better" at this than 3 hours ago when I started this project!!

Don't fear! I cannot let all this advice and opinion go to waste - I will carry on...one mistake at a time!!
#35

Philco didn't make this easy when they used the same schematic to show different chassis with different tube counts, with their dotted lines and crossed out connections, especially if you aren't an old hand at reading schematics. After 1940 they didn't do this as much.

I've always found it helpful to make careful diagrams before I change a component or wire, using schematic symbols for resistors and capacitors rather than drawing their shapes, and labeling the values next to them. I draw the wires in with colored pencil, using dotted colored lines for wires with tracers. Before I solder any connection I double check my diagram against the schematic. The diagrams take time, but they give me more confidence that I can put things back the way they were. Slow and steady wins the race. For me, it's more fun and less frustrating that way.

But I still occasionally blow it, like the time I scratched my head a long time when I left off the resistor that supplies B+ to the mixer tube on a 40-190, then did the same darn thing on a 40-150 a few months later!

Except for old repairs, your radio is probably wired correctly, so even if the schematic is confusing, you can always fall back on putting things together as they were, and you'll be right almost all the time.

Your radio is a pretty complicated one to learn on. It does get easier!

John Honeycutt
#36

I like the idea of drawing it out too. I do find a sense of awe looking at a 75 year old piece of work. That this radio could pick up shortwave from Europe during the war is outrageous. to wonder if those listening (the original owner were manhattanites and had a summer home here in Wading River where ultimately all these great pieces were auctioned off, were from Poland and 1st and 2nd generation!) -
#37

    So I saved some money and sent the chassis and enclosure to a local professional -He replaced caps, resistors, bad tube, fixed some broken insulation, you know the normal stuff in a 74 year old radio. 

The tuning section only required cleaning and the presets actually were still spot on!!!

at night, on the east end of Long Island, NY, the dial comes alive with broadcast and SW stations. Last night the kids listened to the Red Sox BB game and some music from 1500 Am out of Pittsburgh. 

Absolutely amazing, and my 16 year old daughter pinky promised me that she would get the radio when it was time to move it.

That's special!

David
#38

Very nice!!!!

Don't let KIRK near it!

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
#39

WELL,,,I see,,that all the Great gentleman are on here answering your questions,,,there are some things that I,,,have learned here,,,,draw out everything you can,,,tape out capacitors and resistors (mark out their number) on it,,,if you replace a capacitors,,you can use Non Polarity ones ,,check resistors or replace,,,(one leg off to check),,take picture with camera,,,DON'T get overwhelm,,,do a little at a time,,,it doesn't matter how the part is in the set,,,as long as it is in some type of order,,,,could be any were,,,,Have fun,,,,Cheers




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