[TenTec] pEGASUS - (Kachina comparison - long)

[Duane Grotophorst]

--- Jerry Harley <wa2tti at worldlynx.net> wrote:
> I've been on this list for a long time, but I don't
> think I've ever seen a 
> comparison of the Pegasus to the Kachina 505.  I
> would like to hear any and 
> all comments.  Jerry
> 

I have both a few Pegs and a Kachina 505DSP here.
While I have spent far more time using the Pegasus, I
have played enough with the Kachina 505DSP to have a
good basis for comparison. I’ll try and list all of
the various points/features I can think of and offer
my mostly subjective observations/opinions.

Sensitivity:
>From my A/B antenna switching exercises - no
appreciable difference, I think that you will find
this to be true of all modern receivers, sensitivity
is rarely an issue today anymore. Keep in mind what
many folks today refer to as a lack of sensitivity in
newer radios is in reality a question of overall gain.
The real test is if you can detect the signal above
the noise or not, not how loud the radio can make that
signal (and the noise).

Selectivity:
This one is not nearly so ambiguous. The 505DSP has
significantly better shape factor filters, - but fewer
of them, with the 6Khz filter being restricted to AM
use. The Pegasus has 34 filters; their shape factors
are more like crystal filters, at least for the
typical SSB bandwidths. The narrower Pegasus filter
widths like those typically used for CW do not seem to
be as good as equivalent crystal filters (again shape
factor). The 505DSP’s filters are very sharp for all
bandwidths. One distinctly differing trait between
them is that the Pegasus filters seem to have a
“softer” sound to them, the narrow 505DSP’s filters on
the other hand are more reminiscent of crystal filters
and what they do to/with the noise inside their pass
band.

Noise Reduction:
This one depends on what you are doing, the 505DSP is
better for eliminating noise on weak signals, it will
bring them up out of the noise, it does however impart
some of the “watery” qualities (for all signal
strengths) that DSP filtering is so often criticized
for. The Peg on the other hand doesn’t do that, but it
won't however help you all that much with signals
weaker than S7-8 or so, it doesn’t bring them “up out
of the noise” as much, (it tends to take the desired
signal out along with the noise). However for rag
chewing on a noisy band, and with decently strong
signals, it is more pleasant to listen to than the
505DSP and does an excellent job.

Strong Signal Handling:
The 505DSP is significantly better here, but with one
major oversight, - no RF gain control.

Control Software:
This is where the Pegasus wins in spades, there is
only one control program that I’m aware of for the
505DSP and that is what Kachina wrote themselves, it
has some neat “thinking outside of the box” concepts
in it but it needs a ton of further refinement and
expansion. I really like what was done for the S Meter
presentation, a nice big easy to interpret bar graph,
no “virtual” analog S-Meter there, not too keen on the
vertical presentation though. One other thing I really
like in the Kachina software is that most of the
status displays are “click-able” and can be used to
change various settings without having to drill down
through the menu bar items at all, a real nice touch.
Control software is the key area where the Peg wins,
simply because there are several different software
packages written for it, it gives us users more
choices. Control software is one area that I think the
Kachina folks had completely miss understood or
underestimated what they were getting into, they were
far too passive with control software development,
either writing their own, or in supporting third party
authors. Even Ten Tec isn’t nearly as aggressive as
they should be in this regard (in my opinion of
course).

Firmware Upgrades:
The Peg has distinct advantage here, it is very strait
forward and easy via RS232. The 505DSP requires the
swapping PC (PCMCIA) cards. With the 505DSP having
been discontinued this point is now pretty much moot.

Spectrum Sweep
Pegasus wins here, I think mainly by virtue of having
faster RS232 connection, 57600 vs. 9600 baud. I think
that Peg also gains some additional sweep speed
advantage by using a simpler (more RISC like) command
structure, for the 505DSP there is a lot of data
having to be squeezed through that slooooow 9600 baud
connection.

Antenna Tuner:
Haven’t used the 505DSP’s AT enough to comment in a
meaningful way, the PT11 for the Pegasus isn’t as good
as it could be, perhaps the new version that is soon
to be released by LDG will correct the awkward
integration of the original PT11.

Fit, Finish, and Construction:
The 505DSP is more polished with better choices of
screws and other miscellaneous hardware. In a broader
conceptual way though the 505DSP is arguably
unnecessarily complex (particularly board layout). It
uses a back-plane board with several plug-in modules.
The Pegasus on the other hand is a simpler, and quite
clever design, there are basically 3 key boards that
plug into each other in a 3 dimensional way. This I
think gives the Peg the advantage not having any long
length (and electrically noisy) digital signal busses
passing through a back-plane type structure which is
more prone to EMI coupling issues. The 505DSP on the
other hand I think had to include the additional
shielding on each of the boards themselves to
compensate for the greater internal noise being
radiated from the back-plane. Interestingly for the
new Orion it looks like TT is also using a back-plane
(perhaps more accurately “backbone”) type of layout,
but with a few key differences. One is that it is
sandwiched between aluminum panels and therefore is
provided with some degree shielding, it also looks
like it doubles as the interconnect for the front
panel “brains” and back panel connections. It also
looks like (based on pix I’ve seen) that there is a
minimum, - if any digital bus type signals on that
backbone, perhaps represents “lessons learned”. One
thing that they both did is try to make them look like
“mini computers”, which I think is unfortunate, I just
want my radio to tightly integrate with my computer, -
not look like it. I would actually like them to be
more like the simple, no nonsense case design of the
RX320 (my opinion again).


If I had to pick one over the other I would choose the
Pegasus; it is a decent performing and economical
radio with pretty darn good software support. I also
suspect that it is probably more reliable by virtue of
its simpler mechanical (board layout) design and fewer
board inter-connections. If on the other hand if you
just want to have another radio to play with by all
means pick up a 505DSP, - on the used market they are
selling pretty inexpensively of late. As far as I know
the 505DSP is still being serviced by the factory, but
for how long who knows. Now if there just was some new
control software for the 505DSP, it would be a lot
more fun radio than it currently is, its very good RF
performance traits deserve it!!

Duane
N9DG



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