[Milsurplus] 1155

[Jack Antonio]

On 7/7/2012 12:15 PM, J. Forster wrote:

Neither the BC-348 nor the ART-13 was available at the start of WW II.

Not so sure about that concerning the  -348. I have a BC-224-B which
has a contract date of 5 January 1939. My -348-C has a contract date
of 1941. At least the 348 was available very early in the war, and 
certainly predates the AN/ART-13.

 > OK, the SCR-522 was a POS. At the time it was introduced, what was 
better?
 >
 > -John

After collecting and firing up an SCR-522, I feel it is actually a
decent set, given the technology of the time. Certainly better than the
WE-233A (AN/ARC-4).

However, the SCR-522 has some rather interesting design "features", it 
is not a simple set to troubleshoot.  I don't know if these
"features" were a result of its British legacy, or Bendix, who
seemed to be fond of rather convoluted control schemes.

First was the regulated 13V filament voltage, in both the 12 and 24
volt versions.  The dynamotor provided the filament voltage, and had
a carbon pile regulating the field current.  Indeed I have read
that the original dynamotor supplies were maintenance dogs and had
to be redesigned.  The regulated filament voltage never appeared on
later WWII VHF radios.

Second was a PTT scheme that had a relay drop out for transmit and
energized for receive.  The entire PTT scheme involved multiple relays
and is not a straightforward thing to trace. To me, it seemed to
be overcomplicated, and I've wondered what the design goals were
that warranted it.

Jack Antonio WA7DIA/4