On 13 Mar 2002 at 5:07, Tom Rauch wrote:
>
> That's why I won't buy a DSP based radio. Performance is poor
> enough using conventional filters because the filter follows too many
> mixers and semiconductors.
>
If I correctly understand the write-up released by Ten Tec,
there will be no ham radio transceiver available that has better
filtering than the Orion. In fact nothing will even come close.
With crystal roofing filters of down to 250 hz followed by the
DSP filters, how could anything be any better? In this case, you
have very narrow bandwidth very close to the antenna. Add to
that a low phase noise HF oscillator system and narrow band
front end filters [I admit I am guessing on this one but I'm
taking it from the statement that the primary receiver is ham
band only] and a mixer at least as strong as in the RX-340 and
you have a receiver that has selectivity beyond anything we have
yet experienced.
> Not only that, have a listen to keyclicks and other trash from newer
> radios.
>
I'm not sure what DSP based rig you are thinking of here but I
can tell you for certain that the Pegasus/Jupiter do not create
key clicks. We have already discussed this matter at some
length and I have performed some lab and listening tests on my
PJ's and found them clean. Remember that the keying waveform
took the ideal raised cosine shape and except for a very small
overshoot on the first element, was text book perfect.
> The last thing I want is a receiver that moves selectivity even
> further back in the system running at frequencies my dog can hear so
> marketing departments can say it is "true IF DSP".
>
Selectivity far back does not preclude selectivity up front. In
fact, the Orion has a lot of front end selectivity. What modern
rigs other than the Orion and Omni's V and VI's have ham band
bandpass filters in the front end? This is an example of Ten
Tec's devotion to performance as opposed to marketing. It is
generally considered that a ham band transceiver should be
general coverage receive. But to do that, one must be willing to
accept a lower level of performance than ham band coverage only
will deliver, all other things being equal. Ten Tec took an
innovative approach on the Orion in providing both. One receiver
limited to ham band coverage and another for general coverage.
> It appears we have been brain-washed by the marketing
> departments into ignoring performance!
Again I am not sure what DSP radio you are referring to. As in
most things, I have no doubt there are some really bad DSP
based radios and some really good ones. BUT, do you truly
believe that Ten Tec is ignoring performance in the Orion? I
don't. In fact, it looks to me like they are focusing on
performance at a level heretofore unseen in ham radio
equipment.
I was a skeptic when I bought my Pegasus. In fact, I had every
intention of returning it within the 30 day trial period. Guess
what? The Pegasus has become my rig of choice and has crowed
out rigs costing two or three times as much. The Peg is not a
"perfect" rig, but it packs a lot of "fun" power and at the end of
the day, I can say it is the best value I have ever received in a
piece of ham radio gear. Part of that credit must go to Carl,
N4PY. And herein lies another advantage of software defined
radios. Carl has taken a rather basic radio and made an
extremely flexible and easy to use radio.
I don't think the Orion will have a user interface like the PJ's,
at least on first release. I sure hope TT eventually does one so
Carl can work his magic. Can you imagine what a
hardware/firmware platform like the Orion and an open user
interface would be like???? This is an exciting time to be
involved in amateur radio!
On the 30 day trial............You don't buy a TT radio until you have
had a chance to try it out. You can make sure the selectivity is
what you want and there are no key clicks and whatever else is
important to you. I think that alone is worth considering Ten
Tec gear in any new purchase decision.
-73-
-Lee-
> 73, Tom W8JI
> W8JI@contesting.com
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