What does Hot A and Hot B Mean?
- Hi ScottWhen using meteor scatter the highest probability of getting pings is in the direction of the Hot spots which are a little either side of the direct path. Depending on the time of day one hot spot is slightly favoured over the other and WSJT works this out and highlights it in red. Thus to optimise making a QSO both stations should beam at the Red highlighted hot spot.The hot spots are only important if you are using a high gain beam as small antennas say up to 6 elements will see both Hot spots when beaming on the direct path for typical paths of 1000 km plus..73 Rex, VK7MO
- For a brief discussion of why hot spots are "hot" and other topical
papers on HSMS, take a look at:
73, Joe, KB1CJ
The difference between Direct Pointing and Hot Spots is only a few degrees and in my opinion will not make or break a contact. The accuracy of pointing the antenna for me is limited by the following items: 5 degs increments that are hard to see and even harder to set the needle exactly on a single degree increment, rotator play (slop in the gears and inherent movement), accuracy to which I calibrated the rotator indicator being yet another variable and then my ability to read the very small scale on the rotator all have to be taken into consideration. So after striving to be as accurate as I can there is a strong probably I will be off a few degrees anyway thus if exact point were required I probably wouldn’t make too may contacts.
I listened to the Six Meter N0LL beacon for five minute periods letting WSJT count the decoded R26’s in the “Decoded.cum File” using seven different antenna directions. Here is what I was decode using Degs / R26’s with DF -20
When I run this little test, I set the Parameters accordingly W = 20 S = 2 ST = -5 DF -150
Now according to WSJT the N0LL beacon is 719 Miles, Az 352 Degs; RED Hot A 342 and Hot B 2. It also recommends an elevation of 6 degs.
So you can see that the distribution of pings was over a range of 90 Degs. (This is real data) For that particular test frame 330 Degs had the most pings with 92 for 5 minutes. I have ran this test many times and the distribution is always different but it always indicates that antenna pointing for this beacon / distance combination is not critical. It is also interesting to look at the signal dB strength, the stronger pings are not always in the Hot or Direct directions!
I do believe that the distance for the above data test is the optimum distance for meteor scatter on six meters. I believe that greater distances of say 1000 miles will narrow the range of decoded pings perhaps 10 to 20 degrees and with distances over 1200 miles resulting in an even smaller window for receiving pings.
I have been unable to do any testing using two meter beacons because of reception problems. N0LL has a two meter beacon but I never hear it and have been told it is not stable enough to use for such a test. My personal feeling is that two meters requires much more diligence when aiming antennas for meteor scatter qso’s.
My antenna by the way is a M2 Seven Element beam at 52 ft.
Tip (home alone today if you couldn’t tell)
From: ecoblue_divers <ecoblue_divers@...> [mailto:ecoblue_divers@...]
Sent: Wednesday, January 22, 2003 9:56 PM
Subject: [wsjtgroup] What does Hot A and Hot B Mean?
What do HotA and HotB mean and how should I use those azimuths to myTo unsubscribe from this group, send an email to:
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