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Re: [IRCA] Loop Antenna Gain for Rockworks #4 and #2



<<<ÂÂ ... but DX heard on the Rockworks #4 SDR file 
was cleaner and less affected by the splatter compared to the same signals 
at Rockworks #2.ÂÂ >>>Â 
 
Thanks for your comments, Guy. 
 
It'sÂprobably wise to remember that Rockwork 4Âlikely has the best splatter-killing geometry on the entire west coast, with a solid rock cliff extending far above the turnoff site, complete with a wire grid to stop rocks from falling on DXers (and sleeping squatters). Backside signal rejection is so impressive that the siteÂcan evenÂmake figure-8 FSL antennasÂseem like they have some serious F/B ratio. Rockwork 2Âhas nowhere near the same ideal geometry, with gently sloping ground below the site, and aÂlackluster sloping cliff above it. That one factor alone could account for the splatter reduction you noticed at Rockwork 4.ÂÂÂ 
73, Gary DeBock (in the valley) 
 
 
 

----- Original Message -----

From: "Guy Atkins" <dx@xxxxxxxxxxxxx> 
To: "Mailing list for the International Radio Club of America" <irca@xxxxxxxxxxxxxxxx> 
Sent: Monday, October 26, 2015 9:15:40 PM 
Subject: Re: [IRCA] Loop Antenna Gain for Rockworks #4 and #2 

Hi Chuck, 

My apologies for not considering gain differences. I was too "wowwed" by 
the obviously lower splatter levels on Dave's Rockworks #4 SDR files 
compared to mine from Rockworks #2 on the morning of October 24. 

I did no adjustments, but just zoomed in on specific signals to see the 
peak signal level and the level of the lowest "valley" in the noise nearby 
in frequency, and observed the difference as the station's S/N ratio. 

The antenna I was using is reportedly 9 dB "hotter" (compared, I believe, 
to the original ALA1530 used by Dave). I'm not sure how that affects the 
observed S/N on various signals, but DX heard on the Rockworks #4 SDR file 
was cleaner and less affected by the splatter compared to the same signals 
at Rockworks #2. 

What I know for sure is, if you can't be at Masset, Haida Gwaii, then 
*45.743417, 
-123.957941 
<https://www.google.com/maps/place/Manzanita,+OR/@45.7434236,-123.9582682,103m/data=!3m1!1e3!4m2!3m1!1s0x5494b61a5fb38495:0x9b94c876e8acf657!6m1!1e1>* 
Âis the place to be! 

Best DX, 

Guy 




> From: Chuck Hutton <charlesh3@xxxxxxx> 
> To: "irca@xxxxxxxxxxxxxxxx" <irca@xxxxxxxxxxxxxxxx> 
> Cc: 
> Date: Mon, 26 Oct 2015 05:00:02 +0000 
> Subject: Re: [IRCA] Interesting Rockworks Discovery & Oct. 25th DX Comments 
> Guy - 
> All true, and all already mentioned.But what I was asking is whether your 
> numbers were adjusted for the difference in antenna gains.I'm trying to 
> compare apples and apples as much as possible. Just like we can't just 
> compare raw numbers for systems with preamps of different gains without 
> mentioning the difference, we can't compare the Rockworks numbers without 
> mentioning the differences between Dave's system and yours. 
> Chuck 
> 
> 
> 
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