[600MRG] XJM Tests

[Lee Mushel]

Jay is right on!   I have three different HF rigs attached to three 
different antennas all within a 350 ft. radius.  One of my odd interests is 
"watching" how fast and how deeply the signals change when all rigs are 
tuned to the same frequency!   All are software defined radios so the 
dramatic changes are easily viewed on the video displays.   Everything is in 
a constant state of flux so if you are going to evaluate mode performance 
you can't do it with multiple radios and draw any meaningful conclusions. 
Don't forget that there is a reason why "dual diversity" works!  And if you 
are fortunate enough to be able to watch a couple of hundred kilohertz of 
spectrum you see old mother nature literally "wipe" effects across the 
screen.  And then as far as "readability" is concerned you have to make sure 
your detectors are tied to a common oscillator.......phase effects can be 
spectacular as well!  One of these days I intend to build another 
upconverter but I don't expect anything to settle down from a move from 160 
meters to 630.

73

Lee  K9WRU
----- Original Message ----- 
From: <jrusgrove at comcast.net>
To: "600MRG" <600MRG at w7ekb.com>
Sent: Wednesday, February 12, 2014 7:28 PM
Subject: Re: [600MRG] XJM Tests


> For an accurate comparison you need to use one receiving setup ... one 
> antenna, one sound card, one computer. Run both programs simultaneously.
>
> Jay W1VD  WD2XNS  WE2XGR/2  WG2XRS/2
>