Great post Bill...thanks.
It's good to know others are finding the same thing with the programmable
AGC. I have found my settings correlate with yours when I'm trying to dig
out a weak signal on 80m...and at times the improvement is pretty
astounding. I also have noticed I seem to be able to copy some very weak
signals on 80m CW that others can not seem to copy...but that was pretty
common when I used to use my Omni 6.
What pretty much amazes me is that several years ago (I bought an Omni 6 in
1992) my impression of the Omni 6 was that it had a pretty darned decent
receiver, but I wanted to know for sure how it compared with other
'high-end' rigs. I bought an FT-1000MP and four different IC-781's and kept
them on my desk for about six months (except the MP only lasted 3 months)
and did hours of A/B antenna switching with my own set up. The Omni
certainly could hear weak signals in the noise that the MP could not hear at
all. The IC-781's certainly hear the same signals as the Omni, but it's
ability to handle QRN on 80m was no match to the Omni. I was convinced the
Omni 6 was the best receiver, in my own station set up. WRONG!! My Orion is
definately a better receiver in my new station set up (QSY'ed from VA. to
south GA.). A/B antenna switching at the new QTH shows the Orion will let
you copy signals that the Omni 6 can tell are present, but you just can not
copy them.
This is not a conclusion, but after loading v1.369 last night, and listening
to 80m this morning, I noticed a pretty significant reduction in the
background noise. The same thing for 40/20/17 and 15m this morning. No
conclusion can be made as it's quite possible that band condx are just quite
good today, BUT it's pretty darned impressive. Does it have anything to do
with the firmware update? Nothing in the revision history seems to indicate
that....but there is sure a difference this morning.
Wonder if other's are noticing the same thing...or is it just unusually
quiet band condx today?
Tom/W4BQF
----- Original Message -----
From: "Bill Tippett" <btippett@alum.mit.edu>
To: <tentec@contesting.com>; <orion@contesting.com>
Sent: Thursday, February 12, 2004 9:02 AM
Subject: [TenTec] Orion AGC settings
> N5TW wrote:
> >I really have to thank Sinisa for his postings on receiver settings and
for
> W4ZV for underlining their significance.
>
> For some reason Sinisa posted a third on the Orion reflector,
> so here are all three together (in order):
>
>
>
<http://dayton.akorn.net/pipermail/tentec/2004-February/042164.html>http://d
ayton.akorn.net/pipermail/tentec/2004-February/042164.html
> http://dayton.akorn.net/pipermail/tentec/2004-February/042183.html
> http://dayton.akorn.net/pipermail/orion/2004-February/000226.html
>
> Last night I was listening to YI9ZF on 80 while waiting for him
to
> move to 160. He was right at my noise floor and was QRV for quite
> awhile before 0200. It was an excellent chance to play with Orion's AGC
> settings, and also to experiment with K6STI's DSP Blaster on Orion's
> audio output.
>
> Here are the AGC settings I found worked best under those
conditions:
>
> Threshold 95 uV
> Hang .63
> Decay 20 dB/S
>
> Using these, I could take Kas from about 339 to 449, and I seemed to
> be hearing better than most. At times he dropped below my noise floor
> to the point that I thought he had gone QRT. Then he would again rise
> above the noise and be OK copy.
>
> I was frankly astounded at what DSP Blaster would do! It was not
> only helpful for finding Kas' signal using the waterfall display, but
> made Q4 copy into solid Q5 copy. The Coherent CW feature splits the
> signal into in-phase and out-of-phase components, and when you listen
> to this with stereo headphones, it almost makes the signal sound like
> it "jumps" out of the noise, even though it is only a theoretical and
> measured 3 dB difference. I saved both my settings for Orion and
> DSP Blaster so I can experiment more with this in the future.
>
> I got everything set up on 160 after Kas QRT on 80, but he did
> not show up on 160 immediately. Both RA6AX and A45XR had decent
> signals and A45XR was peaking 569 at 0229 near his sunrise. He runs
> a kW to a vertical but with just a few radials, so I expected Kas'
> 100 watts to a 20m high inverted-vee would be much weaker. I was
> amazed to hear Kas on 1837 at 0230 CQ-ing with a 569 signal! No DSP
> or fiddling to copy him 100%, although I had left Orion's settings
> as noted above. I worked him for #311 on Topband and listened to him
> for the next 1.5 hours until he QRT at his sunrise just before 0400.
> Kas peaked 579 so he was even stronger than A45XR was at his sunrise!
> The AGC settings were quite comfortable to use and I could copy most
> of the EU and Russian stations Kas was working (UN7AM was 579!), and
> even many that he could not copy...I felt like I was VE1ZZ! The only
> major problem was when some strong NA stations would call zero-beat
> and of course that took the AGC awhile to settle down afterwards. I
> believe it would be possible to use similar AGC settings in a contest
> especially if you didn't have extremely strong stations inside Orion's
> passband. I may give this a try if I decide to do ARRL DX CW on 160.
>
> Again thanks to Sinisa for causing me to play with the Hang and
> Decay settings. I had discovered the effect of Threshold myself but
> probably would not have tried such high settings for Hang if he had
> not made those posts. I've now had Orion nearly 6 months and am
> continuing to learn new things about how to use it properly! I also
> continue to learn more about K6STI's DSP Blaster which is a fantastic
> program IMHO.
>
> 73, Bill W4ZV
>
>
>
>
>
>
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