[ARC5] RAX Receiver

[Mike Hanz]

On 2/11/2011 3:12 PM, Todd, KA1KAQ wrote:
> As much as I like the ARC-5 receivers and RU-16, the RAX-1 triplets 
> are simply uber cool to me.

I have a warm spot for them as well!  They have their drawbacks, the 
need for three of them to cover the MF/HF spectrum of the era being one 
of them.  The real downer is the lack of the wonderful crystal filter 
capability that the RCA BC-224/348 series had from the start.  The XRAX 
prototype flirted with a broad narrow capability through a tertiary 
winding on the IF transformers like the SX-28 and AN/ARR-7, but they 
don't have the narrow band ability of a crystal.  Evidently the Navy 
didn't consider the possibility of a crowded spectrum to be a concern - 
one of only a few times when they didn't look forward enough in their 
specifications.

The RAX receivers have some positive things going for them, of course - 
the long dial spread is sufficient to obviate the need for a separate 
band spread scale, and I noticed in mine that the noise floor with 
antenna shorted to ground seems lower...probably a result of running 
only 160v on the plates of pretty much the same tubes everyone else was 
using.  Whether that translates into better S/N in actual use depends on 
the frequency and antenna environment, of course.

Any, as Todd says, they are pretty cool for a WWII aircraft receiver.

73,
Mike