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Re: LF: OPERA overload?

To: <[email protected]>
Subject: Re: LF: OPERA overload?
From: "Graham" <[email protected]>
Date: Fri, 20 Dec 2013 17:40:45 -0000
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Jay,

Just pulled these back  from the  psk-data base ,

+ 8 OPERA 0.477 20/12/2013 00:15 United States 1387498502 WE6XGR FN12LQ WD2XNS + 8 OPERA 0.477 20/12/2013 00:32 United States 1387499533 WE6XGR FN12LQ WD2XNS

+8 is 5/6 db up on my signal  over   25 miles  range ,

That's definitely one up from 'Cookie' more to Tall Boy , if Bob runs to double figures , then may be 'Grand Slam'

The spectrum w/f has no link to the decode engine , but , yes under those conditions the noise floor is going to be much higher

Can you generate a local signal 100% op4 , see if Bob will run the timer , give you 4 tx 8 rx window , that would give a value to the drop ?

Use something like spec-lab to give a better view , the w/f in Op is only a indicator / tune aid , what happens to the noise floor , carrier on / off ?

73-G,

--------------------------------------------------
From: <[email protected]>
Sent: Friday, December 20, 2013 1:24 AM
To: <[email protected]>
Subject: LF: OPERA overload?

G

I have to take issue with your earlier comments about OPERA being immune to overload. Check out the waterfall below. I'm looking for OP8 signals out west (UT and VE7) and WE2XGR/6 running OP4 is clearly desensing the OPERA software. Sensitivity can be seen returning to normal between keyed
characters.

The receiving setup is a 1000' BOG (beverage on ground) > Harris RF-590 receiver > Delta 44 sound card. Receiver AGC is off and the received signal level is well below that to cause gain compression in the receiver. Likewise, the sound card is being operated well below compression/clipping levels.

Weak signals do not decode under these conditions ... same as with WSPR.

Jay W1VD  WD2XNS  WE2XGR/2  WG2XRS/2







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