Reverse Beacon Network to test your antennas

I want to show some of you what I have learned about The Reverse Beacon Network and why I think it is an indispensable tool in antenna evaluation.
First, What is the Reverse Beacon Network? It is a website here:  http://www.reversebeacon.net/main.php.
 It basically is other hams with skimming software that can hear a "CQ" on Cw and Rtty , I guess.( I don't do Rtty for this).  These stations are all over the USA and,in Europe roughly 50 of them . The skimmer software is using their computer and  is sweeping a frequency segment , usually the entire cw band plan and maybe even more. It is listening digitally for a "CQ" and your call.  After the CQ stops it sends data to the website over the internet on 7 different  things. First their call. Then your call . Then your signal to noise in decibels above noise . Now your frequency -- code speed and time in UTC.
By going to the DXSPOTS on the RBN website tab you then select a filter (band, for example ) and this is what we see of 17 meters: http://www.reversebeacon.net/dxsd1/dxsd1.php?f=79

Ok now how do we see our self? If you just called "CQ" on 17 meters you will come up from several locations that hear you-- even on your dipole! ! You will be displayed with other contemporaneous "CQ" senders like you.

Ok, now we want to see just our own call only. Go back to DX SPOTS and click the tab "SPOT SEARCH". Type in your call.  Call CQ and enter your call. Actually, enter your call and and then call "CQ" . you will see your call pop up.
Note that if you call cq very fast ,you rarely get an answer. Also technically after your CQ just don't conclude with a "K".Got it?

Now, do you have two antenna on the same band? Call on the first antenna. Note that frequency and time of response. Now change to next antenna and shift frequency . all the calls will be listed vertically on the page but you can see which antenna you were on by the frequency and time you called.   Now place the mouse cursor on a call that heard you. It will light up yellow. Look down at the stations that came in reported on the first antenna-- see if that station was in list list that reported on the second antenna ? If not, go to the next stations until you get a match.  Let us assume that KO7SS reports 22 DB (S/N) on antenna ONE and 16 DB (S/N) on antenna  TWO--BINGO!! You have contemporary reports from the same remote location on each antenna !! Perfect comparison!

Using this concept I have been able to measure front to back on a beam by simple turning the beam between CQs. and then turn the beam and change frequencies. You just need a short span of time between the two CQs on any test to avoid propagational change. 

There is much more on RBN , MUCH MORE but I think many are missing this suggested valuable internet tool for antenna testing and evaluation, so I pass this on. . Good luck, dx , quality qsos  and 73. Mike 

2 comments:

  1. why do you change the frequency? Wouldn't an accurate time stamp be adequate to tell the difference beween your two antennas?

    ReplyDelete
  2. From https://reversebeacon.blogspot.com/ TUESDAY, SEPTEMBER 28, 2021
    If you want to repeat a transmission right away and have the same station spot you again – in antenna comparisons, for example – you must QSY a half-KHz or so before making the next transmission. Skimsrv will not spot you on or close to the same frequency more than once every 10 minutes.
    Your welcome
    -J



    ReplyDelete