[Milsurplus] German Torn E.b Receiver- Suspicious Errors.

[Glenn Little WB4UIV]

Years ago, I recovered a very heavily damaged KWM-2 from a scrap yard.
When I started harvesting the usable parts, I found a wire top a tube 
socket that was crimped, no solder and the red inspection paint on the 
connection.
I guess this was the reason the radio was scrapped.
It probably worked for a while.
73
Glenn
WB4UIV

On 1/25/2024 7:12 AM, David Stinson wrote:
> Every few days, I get a little time to work on this WWII
> German Torn E.b receiver.  Been fixing the damage done
> by someone trying to re-tube it, but there are other,
> more interesting things in here.
>
> First- This radio could never have functioned.
> These solder joints are obviously original, but
> the primary power wiring, B+, B- and Filament
> are all hosed-up from the power connector to the
> power switch and from there to the receiver circuits.
>
> I replaced the missing tube socket, repaired the
> filament circuits, then replaced a couple of bad
> resistors fried by having B+ between them and ground.
> Tested the B+/B- buss for shorts/leakage. It looked
> OK so bypassed the bad wiring and connected
> voltage to the busses for a first test.
> Filament circuit looked OK except the audio tube's
> filament was at 2.2V when the RF tubes were at 1.8V
> That's going to be a Hi-Z ground somewhere.
> Brought the B+ up slow and, touching the plate of
> the 2nd RF tube produced a satisfying racket.
> However, no such response from the 1st RF.  Got
> to measuring and I had no plate or screen voltage there.
>
> On inspection, I found something odd- both the plate
> and screen connections at the tube socket were carefully
> placed and with "molded" solder to look like good
> connections, but once the wires were moved aside,
> neither connection had actually been made.
> I should have take photos.
>
> I wonder if it was just sloppy workmanship and
> rubber-stamp inspection (not like the Germans
> in 1943) or if some poor forced-labor person
> did this intentionally.  Guess we'll never know.
>
> Not the first piece of gear I've found
> "inop out of the box." RBB refurbished in
> San Fran with some of the band switches put
> back 180 degrees off, a ZM-11 bridge with
> wires crossed, etc.
>
> Have you seen factory/depot defects in your mil gear?
>
> GL OM ES 73 DE Dave AB5S
>
>

-- 
-----------------------------------------------------------------------
Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
Amateur Callsign:  WB4UIVwb4uiv at arrl.net     AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)  USSVI, FRA, NRA-LM    ARRL TAPR
"It is not the class of license that the Amateur holds but the class
of the Amateur that holds the license"
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