[R-1051] R-1051 module identification

[David Wise]

The no-suffix R-1051 is 500Hz.  The R-1051A (Air Force?) and B (Navy?) went to 100Hz steps.

>From  what I've gleaned from various documents, the salient difference between the A and the B
is the implementation of the 100Hz synthesizer.  One is IC's, the other discrete transistors, but
the architecture is the same.  There are other subtle differences that make them non-interchangeable.
In fact, substituting may blow stuff up.  A stupid gaffe that could have been avoided easily had
the engineers on the two projects talked.

Dave Wise

________________________________________
From: R-1051 [r-1051-bounces at mailman.qth.net] On Behalf Of John [jlkolb at jlkolb.cts.com]
Sent: Sunday, October 26, 2014 3:10 PM
To: R-1051 Discussion Group
Subject: Re: [R-1051] R-1051 module identification

My memory, based on newly installed R-1051's on the USS Morton in 1965,
is that the R-1051's were originally built with only 1 kHz step tuning.
The Navy then realized they needed 0.5 kHz steps for the carrier freq
of their SSB voice channels, and a field change was quickly done to
convert all existing units.  A R-1051A was the same radio, built with
the 0.5 kHz change from the factory.

Can anyone either verify this, or correct me if I'm wrong?

One of my enduring memories was when one of our three R-1051's failed.
The ET came up with his case of modules, replaced all the modules one at
a time, and it still didn't work.  Put the removed modules into the next
receiver over, all good.  I, a lowly RM2, tilted up the chassis, and
spotted where one of the wires with connector pins had popped out of the
chassis mounted connector.

John
KK6IL