[ARC5] arc-5 BCB RX seen

[Mike Hanz]

David Stinson wrote:

>
> ----- Original Message ----- From: "Mike Morrow" <kk5f at earthlink.net>
> Subject: Re: [ARC5] arc-5 BCB RX seen
>
>
>> The C-26 control box outboard the ATC is for the R-26.
>> In this particular installation, isn't it likely that the R-26 is the 
>> receiver normally used with the ATC,
>> not the RAX-1?  Within it's tuning range, the R-26 wouldn't be much 
>> inferior to the CG-46116.
>> The USN sometimes used the R-26 with the ATC elsewhere.
>
>
> Check the antenna leads.  Both the R-26 and the ARB are wired to the ATB.
> Therefore, since the ATB has an internal antenna relay, the R-26 
> antenna is
> not switched by the ATC, but by the Command Set.
> This leads to some interesting speculation.
> 3 MC and 4 MC frequencies were primary operational
> and ASR, as we've documented in other threads of late.
> I think it likely that, in this installation, the R-26
> acted as a second Command receiver, probably guarding
> either the ASR frequency as required or some other
> primary frequency.  I can't find the hi-rez scans
> around here at the moment.  To what frequency
> is the R-26 tuned?  Can't quite make it out.
> The R-23 tuning goes to the pilot, of course,
> not the radio op.


That seems entirely feasible.  Unfortunately, there was no CONOPS 
associated with this PB4Y-2 Line Maintenance manual and photos, only 
installation details.  The R-26 is tuned to ~5.70MHz, but I'm not sure I 
would put much stock in that since the panel is still being filled out 
during installation - note the missing coax connectors on the 
countermeasures antenna patch panel on the ECM side of the bay to the 
right of the ATB.  The C-26 is tuned to ~5.83MHz...close enuff for 
government work, I guess...   :-)    I also notice that the R-23 is fed 
by the same ATB antenna...

Just for discussion's sake, I put up three of the series at 
http://aafradio.org/sidebar/PB4Y2_Line_Maintenance_Manual.html - the 
photos are all dated 20 July 1944.

> In the second photo- the one of the Radio Op's desk.
> What is that thing with the insulators that would be
> beside his left leg,
> the thing to the right of the fixed/trailing knife switch?


There are actually two things there - a CU-26/ART-13  and underneath it 
appears to be a C-25/ART-13 (or their ATC equivalents).  I posted a 
closeup at http://aafradio.org/sidebar/PB4Y2-067a.jpg.  Note the spark 
plug tips on all the items...heh, heh...

- Mike