[Milsurplus] R-584

[WA5CAB at cs.com]

In a message dated 12/31/2007 12:10:56 PM Central Standard Time, 
kk5f at earthlink.net writes: 
> That clears that issue up.  Just about all web references to the AN/MRC-20 
> cite "R-589/MRC-20."  Hard to believe internet info is sometimes inaccurate!

Right!  :-)

> 
> I assume that the R-584 retained the DM-28 dynamotor.

Yes.

> 
> Were there any other modifications or versions of the BC-348-series that 
> received a JAN nomenclature, other than the generic "AN/ARR-11" and "AN/ARC-8" 
> that applied (in documentation only) to late models? 

None that I can turn up here.

> 
> >According to the manual, R-584 is a modified BC-348-Q OR BC-348-R.  The 
> >for-sure way (because some of the other differences were often ham-hacked) 
> to ID 
> >the parent receiver is to look at the BFO coil.
> 
> For diffentiating between a R or Q, I just say "some grid-cap tubes" 
> (R-model) vs. "no grid-cap tubes" (Q-model).

Well, yes, but I've seen EMOPS and/or HKLR with some or all of the 
double-ended tubes replaced with single-ended.  And I've seen at least one -J with an 
antenna trimmer added.  But I've never seen one of them where anyone had 
replaced the BFO can with a front-panel mounted one from a JNQ.

> 
> >Modifications to convert the BC-348 to R-584 consist of the addition of an 
> >outboard (mounted on top of the cabinet) Squelch and Noise Limiter module.  
> The 
> >module is connected to the receiver through an AN connector installed at 
> the 
> >left end of the front panel.
> 
> Are there any tubes in the external module?  Will the basic receiver still 
> function if the module connector is pulled?

Yes, there are two tubes, a 12AU7 and a 12AX7.  No, the receiver will not 
work without the external module connected.  You could probably get it to output 
some audio with some jumpers on the AN connector but part of the modification 
grounds one end of the audio gain pot and that couldn't be undone without a 
soldering iron.

> 
> Do you offer a manual for the AN/MRC-20?  It sounds interesting.
> 

I haven't but could.  It would only be a few pages plus the original 
manual(s) which you probably already have.  Only problem is that the photo showing the 
modified BC-348-R is of the entire rear of the vehicle and the receiver 
portion is very small and partially in shadow.  There is a pretty good photo of the 
-Q.

Robert Downs - Houston
<http://www.wa5cab.com> (Web Store)
MVPA 9480
<wa5cab at cs.com> (Primary email)
<wa5cab at comcast.net> (Backup email)
   
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