[IRCA] more same stations, different receiving setups

[Nick Hall-Patch <nhp@xxxxxxxx>]

I was having some discussions with Theo Donnelly concerning the 
recent posting of comparative audio files from the Rockworks DXpedition.

The files posted by Gary tended to be recordings of higher signal 
levels than much of the DX more routinely heard.  Comparing 
receptions of  stronger signals may not be the best way to compare 
antennas and systems, as once a signal is a certain level, it will 
tend to sound good on any receiver / antenna combination, unless one 
antenna is particularly inefficient

Comparing weaker signals will more likely separate the men from the 
boys.   Gary obligingly supplied what he regarded as a weaker signal 
from 
Star-576: 
http://www3.telus.net/public/shallpat/rockworks/576-Star-1244z071116CCSW.MP3 
and I went through my NetSDR files from that morning to see what I 
was hearing at that time and 
date:   http://www3.telus.net/public/shallpat/rockworks/576_20160711_1244.wav

Now, that's a difference.   The whip wasn't really up to the task.

Tom also supplied his reception of 576 at that 
time: 
<https://app.box.com/s/vusyc3zcgqepx9lhoxj7hhtqmq51bnv5>https://app.box.com/s/vusyc3zcgqepx9lhoxj7hhtqmq51bnv5 
, and there we can hear the advantage of his delta loop / FLG100

This is a bit more like I expected, that the large amplified loop 
would deliver superior results to the active whip (as would the 
FSLs).    Having said that, so far I've been gratified at how 
relatively well the whip performed, as I primarily wanted something 
that could be reasonably compared to an antenna exactly the same at 
another site, and was easy to carry and deploy, and this seems to 
fill the bill.    Kept me out of the rain too. (I said earlier the 
whip was 3'; actually it is 4'; it was already packed away when the 
question was asked.  Details on the whip are at: 
http://www.amrad.org/wp-content/uploads/2014/12/actant.pdf.pdf 
Although the designers praise the antenna's ability to ignore local 
noise conveyed down the coax shield, I found that I needed to have 
serious common mode chokes based on #75 material at either end of the 
coax to minimize noise from the DXer's computers etc.)

Gary's closing  comment:   "Tom and Chuck's Perseus-SDR + broadband 
loop combinations can sometimes come up with weak DU's on the X-Band 
that the FSL + Ultralight combos have no trace of. The mid-band 
comparisons can go either way. In comparison to broadband loops, the 
larger FSL's seem to have their best performance on the lower 
frequencies of the MW band "


best wishes,

Nick

_______________________________________________
IRCA mailing list
IRCA@xxxxxxxxxxxxxxxx
http://montreal.kotalampi.com/mailman/listinfo/irca

Be sure to register now for the Joint DX Convention
Kansas City, September 9 to 11.  Hotel space is filling up.
Registration info:
http://www.nrcdxas.org


Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx