Dave is getting closer to a valid test. However, testing on two different days (rig and antenna inventory) is not quite useful for obvious reasons, mostly propagation conditions.
A better method is to use a "standard" dipole and two WSPR transmitters; one on the dipole and another on the two different AX1 configurations. Then, the numbers become comparisons against the "standard" dipole. the point is to spend 24 hours comparing one configuration against the dipole and the next day the second configuration against the dipole. Putting the results in a spreadsheet quickly makes antenna configurations' difference apparent. I have done something similar using the RBN, two antennas, and two nearby frequencies on the same band. This method effectively identified which antenna was preferred in different directions and distances. Even so, the differences could change briefly at any time so being able to switch antennas instantly was extremely helpful. Anecdotes, even comparing configurations from one day to the next are not very helpful unless done over many days. WSPR is an excellent tool for antenna and propagation study. A pair of WSPRLite transmitters provide accurate, useful data whereas "I worked..." can be interesting, but not very useful although it is extremely popular. 73, Bill, K8TE Date: Sun, 25 Sep 2022 12:19:03 -0700 From: David Gilbert <[email protected]> To: [email protected] Subject: Re: [Elecraft] AX-1 -- with and without counterpoise Message-ID: <[email protected]> Content-Type: text/plain; charset=UTF-8; format=flowed To be a proper comparison, the AX1 needs to be out it the clear away from anything else, preferable at a height that allows the counterpoise to be hanging straight down with the end maybe a foot or two off the ground.? Measurements should be with the AX1 at the same height above the ground without and without the counterpoise. Ideally a KX2 or similar rig should used, be battery powered (with very short leads if external), no coax, and no body contact to the source of RF.? Signal reports should be in microvolts ... the number of contacts isn't really useful and neither is SNR if the readings are taken over a lengthy period of time. If I can get my hands on an AX1, I plan to either climb a tree or set up a tall fiberglass step ladder for the AX1 as far away line of sight from my home as practical.? I'd use my KX2 for the signal source, using the Tune function to put out RF without touching the KX2.? Near my home I'd set up the portable vertical antenna I described in an earlier post, and feed that to my K3 set to read microvolts.? I'd operate the AX1 (with and without counterpoise wire) and any other antenna for comparison, and have a friend record the microvolts from the K3 as a blind test. I would use the tuner in the KX2 to simulate actual use, but that would of course introduce a variable for possibly different amounts of loss in the tuner depending upon the load.? I don't see a good way to avoid that. 73, Dave?? AB7E On 9/25/2022 7:06 AM, Ron Gruner wrote: > I've just run two tests of my WSPR/AX-1 set-up with and without a > counterpoise. Each test ran 24 hours over the last couple of days. Here are > the results: > > COUNTERPOISE? > YES NO > ------- ------- > Total Contacts 152 129 > Maximum Distance (km) 15,720 17,276 > Median Distance 2,137 1,823 > Median SpotQ 446 398 > > Where SpotQ = Kilometers / [(2 Watts x (SNR in DB + 36))/36) ] > > The WSPR circuit's ground and SMA connectors are apparently providing > enough of a counterpoise to propagate a respectable signal. > > Here's a close-up of the rig with no counterpoise: > https://gruner.com/k4rhg/wspr_ax-1_nocounterpoise.png > > 73, > Ron Gruner > K4RHG 73, Bill Mader, K8TE ARRL New Mexico Section Manager *ARRL - The national association for Amateur Radio**™* Secretary/Treasurer and Past President, Albuquerque DX Association W6H NM Coordinator, Route 66 On-the-Air 8-17 Sep 2023 New Mexico QSO Party 8 Apr 2023 Duke City Hamfest Chairman www.dukecityhamfest.org 15-17 Sep 2023 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
