[evlatests] parameter simplification for the VHF receivers

[Paul Harden]

Ken Sowinski wrote:
> I suggest that we have only one band code "VHF" to select the low
> frequency receivers.  
<snip> > and, eliminates the confusing necessity of having to know whether
 > the script selected "75MHz" or "300MHz".

> Would doing this prevent anything that would be practical and useful
> with the current scheme?

I see no problem with considering 4/P band as a single "VHF" band from 
my limited perspective.  The new Low Band Receivers (LBR) process both 
4- and P-band signals simultaneously at all times, whether or not a 
dipole antenna is connected.  We deliver a 4/P composite output to the 
LO/IF system (via the T301 4/P Converter).  There is no ability to turn 
off one band or the other, and thus you get both bands, or none.

There are also two additional spare receiver channels, not yet used for 
anything, built into the new LBR.  For installation, the spare channels 
are de-energized and unused to not add any noise power to the "VHF" 
output.  They can be activated at a later time relatively easily, and 
their selected filtered frequency will simply be combined with the 
existing 4/P composite spectrum.

As long as the composite receiver output provides no problems to the 
back end, it certainly presents no problems to my end.

Paul Harden