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TT Orion 565 on 160m & optimal setting - part I. by W4ZV

22. listopadu 2007 v 14:40 | Petr, OK1RP |  Operation topics
Hi all,
today I would like to start to talk about an operation practice a bit.
As I have chance to using TT Orion 565 tcvr on Topband also I found that there is big room to play with setting of that radio during an operation.
Some TT Orion 565 newbies (566 also) have troubles to set up their new toy correctly. However, any setting is a very subjective matter I will try to gather as many informations and settings as possible from most experienced DX performers and low band DX-ers to be able to get an idea how it works and how to make own setting.
Orion's AGC Controls
Orion has four sets of AGC settings: SLOW, MED, FAST and PROG. Each set is independently adjustable with PROG providing the widest range of adjustment.
Within RX menu there are three AGC settings (with separate values for each of the sets):
* AGC HANG time,
* AGC DECAY rate,
Here are the AGC settings found worked best for Bill, W4ZV:
(Originally published on Topband mailing list)
At 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.     
Threshold : 95 uV       
Hang : 0.63       
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.     
Here is what Bill, W4ZV wrote to DL6FBL regarding the setting the AGC of the Orion 565 in the contest):
"I can say with certainty that Orion's default AGC Threshold settings are far too sensitive for 160. Threshold is set for 3 uV as default, and the lowest I ever had it in the CQ 160 was probably 30 uV, and sometimes higher. You can easily observe this by tuning to a quiet part of the band and adjusting Threshold to the maximum 192 uV. It will become very quiet (unless there is extremely high storm QRN) at 192 uV. You then adjust it down until the background noise is an acceptable level. [...] The AGC is the most different aspect of Orion and many guys have made the same mistake. [...] Orion really takes a little time to understand. [...] The manual is also at fault for recommending AGC settings for weak signals that are far too low for 160."
73, Bill W4ZV
Well, it is the recommendation by Bill, W4ZV. In the next article I will post the setting from European DX performers to compare it.
73, Petr OK1RP

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