[GreenKeys] Two questions

[Jim Haynes]

On Thu, 16 Jun 2011, Rokumon Cat wrote:

> First, what would be a good rack mount, tube (non-solid state) comms 
> receiver for shortwave to be used to receive RTTY? Yes, I know that the 
> Collins R-390 is the cat's meow of radios, but I cannot justify spending 
> four grand on a radio at this time.

I think R-390As can be had for considerably less than four grand, but
I'm not sure that is the best receiver for you.  It kinda depends on
what you want to do.  For instance, there is almost no RTTY on HF
radio at all anymore, except for the amateur bands and the broadcasts
from KPH.

The trouble with the R-390A is that they are old and heavy and complicated
and thus tend to be in need of maintenance much of the time.  The Collins
51J series, including military R-388, tend to go for a little less than
the R390A and might be a better receiver for you.  51J-3 is the R-388
and has a crystal filter; 51J-4 was the last of the line and has 
mechanical filters.  Then there's the 51S which replaced the 51J series.
As older stuff, the National HRO-50 and HRO-60 receivers are highly
regarded, and are sometimes available in rackmount.  I would not recommend
the SP-600 receivers as in my experience they drift a lot.  The military
R-274 family includes SP-600 receivers and the Hallicrafters SX-73.
I've used an SX-73, but it was a long time ago and I don't remember how
well it performed with respect to drift.

The R-1051 family replaced the R-390A and those are available from time
to time.  They are switch tuned, which makes it easy to go to a specific
frequency but hard to just tune around looking for signals.  So it's
not very desirable for receiving ham radio transmissions since they
come up at random frequencies.

Occasionally you see FRR-59 or WRR-2 receivers come on the market.  These
are humongous and complicated and heavy, but are very stable, using a
Wadley loop.  The English Racal receivers are also based on the Wadley
loop and are somewhat smaller and lighter.

Then there's the whole zoo of receivers and transceivers built for the
amateur market, some of them rack-mountable, some of them general 
coverage, others ham bands only.  If you stick to those that were made
in the SSB era you should get adequate stability.