EME Moon Bounce on 40 meters?
Rick Shepherd, KA8ERS and four other Amateur Radio Operators, K9JCM-Jim, KE5RJX-James, KC2ZUR-Rich and KA1FFY-Ron operating 40M SSB claim to have bounced their signals off the moon.
"Can you hear me now?"
If not wait 2.6 seconds and you will.
On April 11th 2011 at 12:05a.m. Rick, KA8ERS asked the guys to stand-by, He thought He heard another station trying to check-in. It turns out it that it was an echo of His signal. To travel long-path around the earth it takes 134 milliseconds. It takes 1.3 seconds to get a signal to the moon, another 1.3 seconds to receive the signal back (2.6 seconds total) once a successful bounce has been accomplished. Rick and the other four radio amateurs in the QSO confirm that there was a considerable delay of all their signals. They measured it to be just shy of three seconds.
The echo's were recorded by K9JCM-Jim. The moon was in the N.W. sky at about 50 to 60 degrees from Rick's location. They were operating on 40 meters 7.190MHz between 12:05 and 12:20AM EST. Other stations that have confirmed hearing the echo are KJ6LJB-John and KF5KJE-Robert.
Anyone who has experienced echo's on HF or has other information about long delay echos is encouraged to contact Rick at: rsheph (at) columbus.rr.com
If you have recordings of this QSO or similar echos, please share them with Rick, KA8ERS.
Last edited by K7FE; 04-12-2011 at 12:36 AM.
Reason: name spelling
Terry Graves, K7FE
Chief Editor, QRZ.COM
"Some people call CW a MODE but in
reality it is an autonomous LANGUAGE."
I regret that I do not see that this attribution to moonbounce is credible. My recollection is fuzzy, but I believe that the path loss to the moon is of order 180 dB. With low gain antennas and low EIRP's, it is extraordinarily unlikely that this was moonbounce. Especially since the HF absorption is non trivial and the MUF was far in excess of 7 MHz.
Originally Posted by K7FE
Occam's razor does not invoke this as the most likely explanation.
LDE's are always interesting but HF moonbounce is not viable with ham setups at 7 MHz.
This may explain what was happening!
DUBIOUS EME CONTACT
Others as well as myself are quite curious to know the exact parameters and conditions for this alleged contact or signal detection effort. Since any EME contact is a direct function of an RF budget for a given EME path loss, it is necessary to know what each station is using at each circuit end in order to determine, signal detection thresholds (NF/RX sensitivity), EIRP, etc. Further significant factors enter the path loss problem and that are not easily determined, are the high absorbtion values and very rapid faraday rotation phenomena that would be encountered at 7 MHz. It is assumed that the signal detection was completed via normal and common analog SSB auditory means. Another significant factor considered to make such a contact valid, are the 2X exchange of signal report information as well as station call signs in a normally accepted analog SSB format.
The probability of such a valid contact being made on 7 MHz is extremely low.
I was there and made a contact with Rick KA8ERS When the *MoonBounce* Happened.. dunno if was moonbounce or LDE but it was kewl to say the least.. other operators may have been in or around 7.190 when it happened.. so may have a more accurate description or what went down.. but i was talking with rick when the echos happened
Last edited by N4MVP; 04-11-2011 at 07:05 PM.
Reason: LOL typo
I have experienced LDE's twice over the years.
I was monitoring all this excitement last night, but was only hearing static crashes.
All stations had 59 copy including a station in the UK (call sign coming).
In doing my homework months ago I determined that it would be too costly to attempt this experiment on the HF band. But the knowledge I gained showed that it is possible to achieve a moon-bounce on HF if all conditions are optimum. We did experience what sounded like the Doppler effect / phase shifting with severe distortion at times, if fact a couple of times guys did say “what was that”. But most of the calls were readable. This condition lasted fifteen minutes or so and several watched our clocks and the echo did arrive just as the 3 second hand was ready to strike each time. We all are sure that it was not a Long Path echo due to the time interval and the fact that there was only one Echo. LDE’s are just that- Long Delayed Echo’s, key letter being the ‘s. At no time was there a second, third or four echo. Occam’s Razor would (quickly) invoke this as a “long-path” communication. In this case Occam’s Razor is overruled. Confirmations are coming in today via QRZ and e-mail.
I run a modified Alpha Delta LB Plus as Inverted-V at 53 feet configured so that I have a dual four leaf clover patterns which gives me two launch angle’s of radiation. The lower launch pattern is about 20 degrees and the upper launch pattern is about 45 degrees. The moon at the time of the event was just above 45 degrees. And I agree, the probability of making this type of contact on 7MHz is low, however five of us made the contact, we all tried and all parties heard and witnessed the same. There were other stations that did not have optimum conditions as the rest of us that have confirmed the event.
In closing: There are always naysayers who say it can't be done.
Ha-Ha-Ha, “The Telephone”, “who are going to call
Mr. Alexander Graham Bell?”
Was the sation in the UK hearing the same thing?
Originally Posted by KA8ERS
I would estimate the probablity of this being moonbounce at very close to 0%. Something was probably occuring, but it was not EME.
We cannot tax our way to prosperity.
I remember years ago one night a friend of mine and I were checking out our beam patterns on 10 meters and had the same thing happen.Don,t know what it was but it was cool none the less!
The High-frequency Active Auroral Research Project (HAARP) folks did an EME test in January 2008 on 6.792 MHz CW.
However, they were using 3.6 MEGAwatts and 180 turnstile antennas :-)