[TenTec] Orions SO2R in CQ WW RTTY

[Steve N4LQ]

"FOR TOP NOTCH CONTEST GRADE RTTY USE, ORION'S DSP NEEDS TIGHTER SKIRTS"

I noticed how broadly the Orion tuned while doing A/B test between it and 
the Pro2. The PRO2's filters are almost vertical and signals drop like a 
rock at the edge of the passband. You can taper them off by staggering the 
PBT for non-contest operation. At 100hz BW, the Orion seemed really broad in 
comparison.

Steve N4LQ
----- Original Message ----- 
From: "Bob Henderson" <bob at cytanet.com.cy>
To: <tentec at contesting.com>
Sent: Monday, September 27, 2004 4:16 PM
Subject: [TenTec] Orions SO2R in CQ WW RTTY


>I used my Orions SO2R in the WW RTTY this weekend, so I decided to share 
>how
> they performed.
>
> Firstly, both radios were on for the full 48 hours of the event and for a
> couple of hours before.  I operated the full contest without having to do
> any kind of reset at all on either radio.  For me this was unsurprising, 
> as
> the only time I do a master reset is when I download new firmware.  Then, 
> I
> do it as a matter of course.
>
> Overall, I would say they performed superbly.  One particular thing I
> noticed with Orions, which replaced my two FT1kMPs, is that they are 
> better
> suited to SO2R in the kind of setup I use.  What does that mean? Well, I
> have a rather limited station here.  No multiple towers or anything like
> that.  In fact, just one modest crankup with a Force 12 C31XR and a
> Cushcraft XM240.  If you're interested you can see my set up at
> www.5b4agn.net.  This is a new website and my first attempt at it, so 
> please
> excuse it being a little bit raw & obviously unfinished!
>
> The C31XR driven elements for 20/15/10 metres, which are only a matter of
> inches apart, are fed with three seperate feeders.  I operate high power
> SO2R using these interlaced yagis.  With driven elements so close together
> you can imagine the rf field presented to the second radio rx is really
> nasty.  Of course, I use band pass filters and stubs to minimise the
> problems this causes.  BUT with my two Ft1kMPs I could always feel a
> presence on my second radio when transmitting on the first.  What do I 
> mean
> by a presence?  Well, modulation of the noise floor I guess.  I also found
> that listening on say 20m, within about 10kHz of my 40m second harmonic 
> was
> a bit messy.  What I found with Orions this weekend was that I had no 
> sense
> of a presence on the second radio when transmitting on the first.  Not 
> only
> that but I found myself to have been working about 1 kHz away from the
> second harmonic of my 40m signal on 20m without even realising it.  In my
> view, this experience speaks volumes for Orion's bomb proof front end and
> very low phase noise.
>
> I have only two critiscisms to level at Orion after this weekend of RTTY 
> use
> and one of those I suspect may be down to operator error though I'm 
> unsure.
>
> 1.  My contesting software is Writelog. I ran both Orions set at 250 Hz 
> b/w
> most of the weekend. Whilst tuning around the bands looking for mults etc 
> I
> band map wanted stations which don't answer me after a couple of calls.  I
> then periodically return to their band mappped frequency to see if their
> pile up has subsided.  The problem I found is this:  Every time I clicked
> back to a mapped frequency the rx b/w changed.  If I had only one Orion 
> then
> I would probably be thinking this was a logging software problem but I
> don't, I have two and although the bandwidth changes on both it's not to 
> the
> same setting.  On one radio it always goes to a barn door 1 kHz but on the
> other it always goes to 300 Hz which isn't so bad.  Though, I'd much 
> rather
> it stayed at 250 Hz  where I'd set it.
>
> What determines the b/w set when frequency is changed via the RS232 port?
> Why is it 1kHz on one Orion and 300 Hz on the other?  Anyone know the 
> answer
> to this mystery?  Should I just RTFM?
>
> 2.  Filter shape factor is really the only significant concern I had over
> the weekend.  With b/w down at around 250 Hz the DSP shape factor is not 
> far
> short of 3:1 which really isn't good enough.  As a consequence, folks 
> could
> sidle up real close to Orion's beautifully clean signal and sit there 
> inside
> my passband causing me grief.  I spent way too much time over the weekend
> inching up or down in frequency to avoid QRM from folks alongside.  This
> leads me to the following conclusion:
>
> FOR TOP NOTCH CONTEST GRADE RTTY USE, ORION'S DSP NEEDS TIGHTER SKIRTS.
>
> Incidentally, FWIW the weekend was a lot of fun.  I put in 36 hours and
> finished with he following tally:
>
> QSO: 2582;  Points: 7550; State/Prov: 100; Countries: 271; Zones: 94 for a
> total score of 3,510,750
>
> I was placed 4th last year in SOAB (HP).  This year my Q's are up by 
> almost
> 11% but mults are way down and as a consequence so is my claimed score 
> which
> is about  5% short.  Things get tough when 10 metres dies!  Hopefully, 
> just
> as tough for everyone.  We'll see when the results come out.
>
> 73, Bob
>
> Bob Henderson, 5B4AGN, P3F
> Giolou, Pafos, Cyprus
> Email: bob at cytanet.com.cy
> http://www.5b4agn.net
>
>
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