Fw: [Premium-Rx] Cubic 3030 Rx

[refmon]

Hi Group,

I had inadvertantly responded directly to Richard.  As I am always trolling
for ideas, I'd like it to go to the list in case there's any other 3030 work
going on that I don't know about.  I have added a few additional points
since my original note to Richard.

Soooooooo.....


> Hi Richard,
>
> I generally agree with the info you're receiving thus far as regards the
Cubic
> R3030 series receiver in it's stock form.  First warning---do not confuse
the
> R3030 series with the current 3000 series receivers.
>
> Keeping in mind that many if not all Premium Receivers are intended to run
in
> automated or semiautomated systems, here's what you can expect to
> find, all of which are annoying from the perspective of a user who sits at
> the receiver for hours of weak signal searching:
>
> Idle gain on an empty channel is far too high by 30-35db...result is an
> exhausting roar rather than the gentle rush with static crashes
> intermingled.  This is can be fixed.
>
> AGC is the hang-type, and is set up such that return to "no signal" is
quite
> fast.  Result is severe pumping on SSB or CW signals.  This can be cured.
>
> There is a heavy click when the receiver is hit with the leading edge of a
> strong signal.  This can be cured.
>
> The receiver radiates fairly heavy digital noise which in a home setting
may
> be picked up by your antenna.  This can be fixed.
>
> The R3030A, in particular, has bouncy keypads and often has loose keypad
> legend overlays.  This can be fixed.
>
> The R3030, in particular, has no speaker outputs.  This can be fixed.
>
> I have never found any two receivers that track in terms of alignment or
> meter readings.  This can be fixed.
>
> Hobbs-style hour meters tick rather loudly...slow torture...easily fixed.
>
> Synthesizer phase noise is a little high ... mods are being considered.
>
> There are a few other issues that are no big deal.  By the way, this is a
> nitpicked list of items that I expect is no longer and is much simpler to
> deal with than with many other Premium Receivers.  Note that the Cubic
> receiver, in spite of its sealed case, > does not suffer from overheat and
> meltdown.
>
> The great thing about this series of receiver is that it is built like a
> battleship, uses discrete IC and transistor circuitry, so is easily
modified
> or repaired, and it uses plain old everyday parts.  I have developed and
> installed modifications for each of these issues and will be releasing
them
> to the Premium-RX list.  Most of the modifications are resistor changes or
> additions, capacitor changes, addition of shielding.  Some of the
> modifications require signal generator and spectrum analyzer or
pan-adapter
> for fine tuning, but I've gotten reasonable results without.  A couple of
> other list members have been digging around in these receivers and we've
> been exchanging ideas on these mods.
>
> Note the AM demodulator is not all that great and modifications have not
> been done at my location.
>
> I am currently working on LabView 7.0 applications which include the
> R3030 control via GPIB.  The 3030A is by RS-232, which I have not
> played with, although the protocols are quite straight forward.  My
> applications currently concentrate on automated sweeps and record/plots,
> scans with audio recording and logging, etc.  Also integrated into the
system
> are Watkins Johnson 86xx receivers, HP spectrum analyzers, etc.  In the
end,
> coming up with a control console for the R3030/R3030A should be fairly
simple.
> The problem will be that I am not in a position to develope a
comprehensive
> system...mine will be more task-specific.  I also cannot define a time
frame,
> as is evidenced by the time it has taken me to get my modifications
package
> "almost done".
>
> Spares for these receivers are pretty rare...that is, modules, boards, etc
> are few and far between.  The receivers are not particularly prolific
> either, although there are occasional bursts of availability.  I'd expect
to
> pay real money for these in good shape and intact.  Take a look at Ebay
> prices asking and sold-for...surprisingly, these track private sales
fairly
> well.  Any sign of fiddling or missing modules and I'd cut the price big
> time.  The point is, no need to buy a beater...patience will net you a
good
> condition, complete receiver.
>
> good luck in finding a receiver, whatever it may be
>
> John Collins
> ______________________________________________