[R-390] Staggertuned IF's and the 1956 TM

[Tom Norris]

For folks that don't have a copy of the older manual to compare and  
contrast procedures, I did up a pdf of the alignment procedure from  
that year.  It includes a couple real, honest to goodness halftones  
of the two versions of the if subchassis. That manual is chock full  
of photos that look like photos rather than bad photocopies like in  
many of the logsa manuals.

r390a.fernblatt.net/1956_IF.pdf

As far as R-390A's go, that's a pretty significant year.  If you look  
in most of your later change lists, that year's Motorola contract -  
0014-PH-56 - incorporated a majority of the listed changes*.  1956  
was also the year after Collins' last R-390A contract**; Motorola  
would build only one more run under contract 14385-PC-58-A1-51.   
These two Motorola contracts introduced the new specification of  
fused  B+ lines, with a production mod starting with s/n 2683 of the  
1956 contract.

None of this counts any of the special Navy mods and I'm sure folks  
that had to wrestle the things in the field can think of many more  
mods and changes. (not counting those in changes 1 through 4 to the  
TM) The basic theme of this email was "1956" so I just stuck to it.


73

Tom NU4G,  Not staggering but tuning AM broadcast on the 390A at the  
moment...


notes:

*Sec 1 par 2c, TM 11-5820-358-35, dated 8 Dec 1961,
    including changes 1 through 4 (Jan 1988)

**The mythical Helena Rubenstein contract was theoretically built by  
Collins....