[ARC5] BC-348

[Jim Haynes]

On Mon, 30 Dec 2019, Whitebear1122 wrote:
>
> Boy those 348’s are gorgeous.  Does anyone here actually use theirs on 
> the ham bands?

Well I did circa 1958.  Those were the favorite receivers of the late
Bob Weitbrecht, W6NRM/W9TCJ, one of the RTTY pioneers.  He developed
a mod where he used the IF transformers from the LF/MF Command Set
receivers to get a narrow passband.  He converted the 915 KHz IF down
to 85 KHz, put it through the transformers, and then converted it
back to 915 KHz and back into the original IF chain.  A neat feature
of this is that you get passband tuning by varying the frequency of
the conversion oscillator.

Mine was eventually extensively modified.  I adopted Bob's narrow band
IF scheme, but instead of the IF transformers I used a bandpass filter
found at a surplus store in Chicago.  Then I made a new rack-mount front
panel, and added a chassis on the back to hold the AC power supply and
the IF filtering and also a product detector.  This was used for a few
years until Bob discovered the Drake 2-B receiver and persuaded me to get
one too.  But I missed the general coverage that the BC-348 offered -
back then there was a lot of copyable RTTY outside the ham bands.

Jim W6JVE