[R-1051] WTT: IF shield can; WTD: Component Layout picture; WTD: AGC Time Constants

[Dennis McLaughlin]

David,

I have a spare IF module marked
4G 5825-439-2375 on the top

58189 ASSY A70244-001 REV.B
MFG 20284  SN.034 on the bottom

Cage code for 20284 is Target Corp.
 From the date codes on the components it looks like it was built in 1975.

It has 13 transistors on the A1 board.
A1 board is labeled as
58189 ASSY
A70653-001 REV A
MFG 20284

I will take pictures of the internals and the cover and sent it to you.

The module does work correctly in my R-1051 plain.

The module that the radio came with is marked
1N5820-078-4725 on the top
666230 011
3313 on the bottom.

I think the new NSN is 5895-00-078-4725
NIIN 000784725
58189-666230-014 is a drawing number.
This info is from PartTarget.

Dennis McLaughlin


On 10/02/2012 01:05 PM, David Wise wrote:
> One of my IF modules is the original General Dynamics part made for the R-1051 plain through C, FSN 5820-078-4725.
> These have only two AGC speeds, fast and slow.  Fast is selected when you set MODE to FSK; otherwise,
> slow is used.
>
> The other is also made by GD, but it's Assembly number A70244-001, which is NSN 5825-00-439-2375.
> (S/N D01434, Rev A.)  Because its A1 board has 13 transistors instead of 9, it has three AGC
> speeds (fast, slow, off), which means it's for the R-1051D and later, which added a three-position
> AGC switch on the front panel.
>
> The only manual I have that covers the 3-speed IF is the R-1051H manual, but I have a problem: my board
> and the manual both show 13 transistors, but the layout is completely different from the picture.
>
> Does anybody have a picture of my board's layout?  Maybe it's in the R-1051D manual or something.  The board
> part number is A70655-001, if that helps.
>
> This IF module came to me in the wrong shield can.  (The right can would have the layout silkscreened, and I
> wouldn't be asking for a picture!)  The can is another 5820-078-4725.  You can have it
> if you trade me a 5820-00-439-2375 can.
>
> My old IF slow time constant is about half a second, and fast is about a quarter-second.
> My new IF slow is about a quarter-second and fast is too short to eyeball.
> Is this normal?
>
> Thanks,
> Dave Wise
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