[Collins] Questions about a 51S-1

[Jacques Fortin]

Hi to all,

 

This is about a Collins 51S-1 found at the usual auction site.

 

>From the published documentation, the serial number lies in the middle of
the 1968 range, so it should had used a Winged Emblem.

Instead of that, it bears a wide RE (nickel size) with two flat head screws
going thru the front paned where the WE mounts should have been.

So from that, it should date from 1969 (RE-transition series).

Third clue: all the electrolytics bearing a manufacturing date within are
from the mid-1966, except the power supply capacitor (C182 A,B,C) which
shows 6717.

It also have a NATO stock number sticker just below the antenna socket which
is 522-2245-030 and all tubes sockets are of the skirted type with IERC
shields mounted in.

The whole unit is complete, unmolested, not modified, never restored. Most
of the tubes are the original RCAs and the tuning tool is in place.

It seems to have low operation hours: apart of a thin layer of storage dust,
no signs of "cooked" air dust are present around the 6BF5 tube.

Under chassis is clean as when it left the factory.

And last detail: V17 is a 6BA6 (both fitted and IDed on chassis) which is
different from the 7543 specified in the 11th edition of the manual.

 

So, what I really got there ??

A military version for sure (R1122/GR), but why the SN / components date /
WE do not match ??

What is the proper version of the manual applicable to this unit ?

 

Any comments or restoration tips are welcome.

 

73, Jacques, VE2JFE