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[TenTec] Re: Dayton news: Orion concern

To: <tentec@contesting.com>
Subject: [TenTec] Re: Dayton news: Orion concern
From: jimr.reid@verizon.net (Jim Reid)
Date: Sun, 19 May 2002 11:48:00 -1000
Mike, W0OJ,  wrote, in part,  earlier:

> after his "hands on" experience with the Orion at Dayton 
> (a friend of mine) has decided to stick with Yaesu.
> 
> His reasons :
> "Homebrew like appearance" (most notably the back of the rig).
> Poor knob placement. (He specifically mentioned a PBT or 
> bandwidth knob as being difficult to operate).
> Cheap feeling main tuning knobs. (I've always wondered why 
> Ten Tec cannot make a rig with a decent main tuning knob 
> such as one on ANY of the competition.)

I will bypass all of those issues IF I decide to buy an Orion
based upon its receiving performance (see my note yesterday
re the rcvg specs achievable these days and reached by
Tom,  W8JI,  with thoughtful engineering designs:  absolute
linear signal path stages,  no AGC applied  to the entire
circuitry up until the conversion to the 2nd IF frequency; the
first application of AGC must not occur until the first amp of
the 2nd IF stage;  all ahead of that,  including rf preamp,  roofing
filter pre/post amps,  etc.  must all be set open,  and absolutely
linear.  This is the way it is done in the RX-340:  The AGC in the 
340 is divided up with 80 db of hardware AGC and 65 db of DSP AGC.
Up to the point of converting to 455 khz, no AGC is used
at all.  All signals at this point are "full blast" inside the 20 khz
roofing filter  within the 340 (20kHz for the SAM AM mode of
the 340).  In the Orion,  the more narrow three "standard"
roofing filters are selectable, plus three optional filters
may be added,  as I understand the Ten Tec info.  

However,  I will look to be sure the Orion front end is set up 
as described above and as it is in the 340.

Next,  the mixers of the Orion must be double balanced 
high-level mixers (driven by at least +10dBm LO power)
to assure very high intercept point operation,  or,  in other
words,  super linear conversion!

Now,  Scott has assured me that the Ten Tec engineers on
the Orion project ARE familiar with Tom,  W8JI,  and his designs;
in fact,  Tom is a friend of Scotts.  However,  Scott advises that
Tom could not be hired by Ten Tec as a consultant because of
his contracts with another firm supplying to the amateur market.
So,  I have high hopes that these straight forward engineering
principles/understanding to reach superlative rcvr performance
are designed in to the Orion!!

Now,  given that all of that is in the rig,  why do I not care about
the "knobology"  of the Ten Tec lay out?  Because,  I will 
control my Orion via software control from Carl,  N4PY who
has already said he will provide same for the Orion.  I am
using Carl's software now with the Pegasus/RX-340 rig and
it is just great!!  I am sure what Carl provides to operate the
Orion will be just as super.  My only lingering,  unanswered question:
will the Orion tuning,  mode selection also be operable from
a remote pod encoder/key pad as is the Pegasus/RX-340
set up? I sure hope so as that is also just great and very
"user friendly".  I presume such will be provided,  as I note
that a socket labeled "REMOTE" is on the back panel of the
Orion directly above the DB9 serial data socket.  And this
"remote" socket is identical in appearance to the socket
on the Pegasus to which the remote pod connects.

I continue to look forward to this Fall with great anticipation.

73,  Jim  KH7M



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