+Applied Science Thanks Ben. It takes a lot better SNR for voice transmission than for CW, mainly due to the extra bandwidth needed. In our case, the incredible 46dB gain of the antenna is what made it possible. Pretty amazing. We had several kids that really got a kick out of speaking the club callsign into the mic, and hearing their voice echo back from the moon.
Now I feel old. I remember the early days of ham EME in the early 60's. UHF gear back then was pretty rare, so I didn't get the chance to actually operate EME until the 1980's. It still is an amazing feeling knowing your signal traveled to the moon and back.
+Denis Obrien It was a pleasure, Denis - although Dan and Norm (as well as Martin, Jeff, Matt) really deserve the credit. All I did was bring the eye candy!
Navarro Eletrônica Brazil I have heard a lot of stuff about for decades from the people there. Prices are insane and it is your govt crushing its citizens. I feel bad for Brazilians.
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***** Yeah, and a lot of hams aren't cordial. I sell my whole station because another ham 50m from here started to speak and use cw above me everytime I started to have some fun but next year i'm planning to move to Canada (to work as an engineer) and I will rethink about ham radio because it's a lot of fun.
Navarro Eletrônica How did he know you were on? The thing about ham radio is there are a lot of frequencies you can use so I would have told him to screw off and moved to another band. 50m as in miles? if meters then you were too close to each other and would need some heavy filtering and narrow band work only.
Alan, how many watts were being passed through the dish? Were you actually using the original FQ of 111.5Mhz but under supervision of an authorized agency or were you operating at a Ghz band the dish was tuned for? Great video!
Absolutely awesome stuff! I am sure you and the others involved had to do a lot of preparation before the event. I mean beyond the coffee and sandwich arrangements. Would be great to know or see (if you have recorded) that part. Say for example, did you have to tune the transceiver to match the antenna frequency? did you have to adjust the gain? did you have reinstall some feed cables to the dish antenna? did you know in advance that the antenna should transmit about 50 MW of power to get a decent received strength? (did you have to do the maths before the event or has the station been always up and running?) I am assuming that the big TV displays were fed by the Tek scopes on the workbench? (And that part surely smells like channel w2aew stuff! :) ). Why are there computer keyboards on the workbench? All in all, terrific! Kudos to everyone who made the event possible in this day and age where it is easy to forget about Morse code and just mindlessly fiddle on the smartphone instead.
I wasn't involved in much of the prep. Princeton Univ has be rehabilitating the antenna for several years (rebuilt drives, rotational components, feed lines and feed horns, preamps and amplifiers, etc.) They also wrote the custom tracking software to automatically track the moon. They also ran the calls, etc. Path loss at 1296MHz is about 270dB (according to a EME enthusiast friend of mine). Keyboards are for the computers that run the tracking system for the antenna, and a SDR they use for radio astronomy. And yes, I brought the scope and spectrum analyzer that are hooked up to the monitors.
How scattered is the reflected signal? Is it very directional or can it be receveid equally on all parts of the Earth which are currently "looking" at the moon (ignoring atmospheric effects)? The same the other way round: how focused is the signal reaching the moon? If you were on the moon would it be the same intensity everywhere or is it more like a "spot" on the moon? The dish obviously being very directional, but not perfect (I guess, don't know much about the beam pattern), how far from the dish is the reflected signal stronger than the stray signal from the dish.
+superdau Moonbounce is done every single day for decades and decades since this experiment happened. If the moon is out where you are anyone else who can see the moon (figuratively or literally) can hear your signal. Fact is you say hello and 2.5 seconds later (give or take depending on how close the moon is) you will hear your own voice saying hello. Very fun and SSTV via moonbounce is fun.
+superdau The amazing antenna we were using has a very narrow 1 degree beamwidth. Even with this, the width of the beam at the moon is MUCH larger than the moon - so it is not just illuminating a spot. The best way to picture the reflection is to imagine how the light from a flashlight would be reflected off of a small polished silver ball. As stated below - basically anyone that can see the moon at the same time you can will have the possibility of EME contact.
+esmaeil nam It's hard to say because recordings from 1946 were pretty poor. They used 111.5MHz, 10MW ERP, and a receiver with only 50Hz bandwidth to get the SNR to acceptable levels. Required very precise computation of Doppler - calculations carried out by Dr. Robert McAfee.
A voltage divider is to be built to give 5v out put from 12v in put figure .the maximum load power is 5v design a divider to provide output range 5.25-4.75v for load rang 3w -5w what is the no lad voltage out the put ?what is the efficiency for two cases of load? can u answer this question sir please
The round trip time to the moon and back at the speed of light is about 2.5 seconds. So when the presenter sent some "beeps" to the moon, as expected, the start of the echo was received about 2.5 seconds after the start of the original transmission. He then spoke into a microphone to send an audio signal. But why did he speak for almost 10 seconds? The first 7.5 seconds of the echo were obliterated by the last 7.5 seconds of the transmission. So we only heard the last bit of his message in the echo. How was a 10 second transmission ever supposed to work?
Nice event! Some time ago I found that there is a whole movement of moon bouncers: www.moonbouncers.org/ I remember looking at some board schematics from German moon bouncing enthusiasts hoping to lift some ideas for LNA. Was it only me who noticed that almost all people on that video are 60+ or older?
+Alexei Polkhanov EME is a pretty popular amateur radio activity - we had no trouble making dozens of EME contacts over the course of the morning and afternoon.
That is so cool! I've never before heard a voice transmission in moon bounce. Thanks for the video.
+Applied Science Thanks Ben. It takes a lot better SNR for voice transmission than for CW, mainly due to the extra bandwidth needed. In our case, the incredible 46dB gain of the antenna is what made it possible. Pretty amazing. We had several kids that really got a kick out of speaking the club callsign into the mic, and hearing their voice echo back from the moon.
Super cool, congrats on EME contact, amazing to think of how far and how fast it really is to go all that distance
Fascinating! And it was good to see you in the video Alan. Usually we only see your hands. Thanks and keep up the good work. 73!
Thanks! Really cool demonstration! I've always wanted to see EME in action.
What a joy to see this video.
Now I feel old. I remember the early days of ham EME in the early 60's. UHF gear back then was pretty rare, so I didn't get the chance to actually operate EME until the 1980's. It still is an amazing feeling knowing your signal traveled to the moon and back.
Thank you Dan and Alan for helping me make my first ever CW EME contact.It was a great thrill.Denis N2JJF
+Denis Obrien It was a pleasure, Denis - although Dan and Norm (as well as Martin, Jeff, Matt) really deserve the credit. All I did was bring the eye candy!
They were geeks before geek was cool! Thanks Alan.
Very nice footage. Thanks!
Looks like a ton of fun dude, probably not very often one has access to such a large antenna. ya, I am a little jealous ha ha great video.
Wow. How cool is that? Thanks for the video.
Big thumbs up
Great video Alan, it was nice to see and talk with you at the event---Bob WB2SRF
+Robert Johansen Good to see you too, Bob. I'm glad that you made it into my video too!
Thanks for the 15 seconds of fame LOL
I built a homebrew 144 MHz dsp radio and 1296 transverter hope to get on the air sometime in the future.
Awesome job Alan, with your permission I will show this at our upcoming Extra class and Club meeting. Thanks for posting! KR0P, John
+Mrjm5411 Absolutely, feel free to share it with your club members!
Great video Alan
Great job guys! Like the Ra symbol on your tag Alan! LOL :^)
Great video Alan. I wish I could been there 73 WW2L
It's the magic of Ham Radio. Hope one day I come back.
+Navarro Eletrônica Same. I have been gone from it for 20 years and miss it and in 3 days I have to put in for my 30th year renewal.
*****
In Brazil it's almost impossible to stay as a Ham guy. Everything is high priced and the people... :(
Navarro Eletrônica
Brazil I have heard a lot of stuff about for decades from the people there. Prices are insane and it is your govt crushing its citizens. I feel bad for Brazilians.
*****
Yeah, and a lot of hams aren't cordial. I sell my whole station because another ham 50m from here started to speak and use cw above me everytime I started to have some fun but next year i'm planning to move to Canada (to work as an engineer) and I will rethink about ham radio because it's a lot of fun.
Navarro Eletrônica
How did he know you were on? The thing about ham radio is there are a lot of frequencies you can use so I would have told him to screw off and moved to another band.
50m as in miles? if meters then you were too close to each other and would need some heavy filtering and narrow band work only.
My first EME QSO 4:30
wonder who supplied the O'scope....
So cool! Great video :D
Alan, how many watts were being passed through the dish?
Were you actually using the original FQ of 111.5Mhz but under supervision of an authorized agency or were you operating at a Ghz band the dish was tuned for?
Great video!
+Brian Streufert Disregard!! I read the info page on eham.net! :-)
Absolutely awesome stuff! I am sure you and the others involved had to do a lot of preparation before the event. I mean beyond the coffee and sandwich arrangements. Would be great to know or see (if you have recorded) that part. Say for example, did you have to tune the transceiver to match the antenna frequency? did you have to adjust the gain? did you have reinstall some feed cables to the dish antenna? did you know in advance that the antenna should transmit about 50 MW of power to get a decent received strength? (did you have to do the maths before the event or has the station been always up and running?)
I am assuming that the big TV displays were fed by the Tek scopes on the workbench? (And that part surely smells like channel w2aew stuff! :) ).
Why are there computer keyboards on the workbench?
All in all, terrific! Kudos to everyone who made the event possible in this day and age where it is easy to forget about Morse code and just mindlessly fiddle on the smartphone instead.
I wasn't involved in much of the prep. Princeton Univ has be rehabilitating the antenna for several years (rebuilt drives, rotational components, feed lines and feed horns, preamps and amplifiers, etc.) They also wrote the custom tracking software to automatically track the moon. They also ran the calls, etc. Path loss at 1296MHz is about 270dB (according to a EME enthusiast friend of mine). Keyboards are for the computers that run the tracking system for the antenna, and a SDR they use for radio astronomy. And yes, I brought the scope and spectrum analyzer that are hooked up to the monitors.
How scattered is the reflected signal? Is it very directional or can it be receveid equally on all parts of the Earth which are currently "looking" at the moon (ignoring atmospheric effects)?
The same the other way round: how focused is the signal reaching the moon? If you were on the moon would it be the same intensity everywhere or is it more like a "spot" on the moon?
The dish obviously being very directional, but not perfect (I guess, don't know much about the beam pattern), how far from the dish is the reflected signal stronger than the stray signal from the dish.
+superdau Moonbounce is done every single day for decades and decades since this experiment happened. If the moon is out where you are anyone else who can see the moon (figuratively or literally) can hear your signal. Fact is you say hello and 2.5 seconds later (give or take depending on how close the moon is) you will hear your own voice saying hello. Very fun and SSTV via moonbounce is fun.
+superdau The amazing antenna we were using has a very narrow 1 degree beamwidth. Even with this, the width of the beam at the moon is MUCH larger than the moon - so it is not just illuminating a spot. The best way to picture the reflection is to imagine how the light from a flashlight would be reflected off of a small polished silver ball. As stated below - basically anyone that can see the moon at the same time you can will have the possibility of EME contact.
Very nice video, thanks. Was the level of noise in the original signal as this one?
+esmaeil nam It's hard to say because recordings from 1946 were pretty poor. They used 111.5MHz, 10MW ERP, and a receiver with only 50Hz bandwidth to get the SNR to acceptable levels. Required very precise computation of Doppler - calculations carried out by Dr. Robert McAfee.
A voltage divider is to be built to give 5v out put from 12v in put figure .the
maximum load power is 5v design a divider to provide output range 5.25-4.75v for load rang 3w -5w what is the no lad voltage out the put ?what is the efficiency for two cases of load? can u answer this question sir please
Good JOB !!! :D
The round trip time to the moon and back at the speed of light is about 2.5 seconds. So when the presenter sent some "beeps" to the moon, as expected, the start of the echo was received about 2.5 seconds after the start of the original transmission. He then spoke into a microphone to send an audio signal. But why did he speak for almost 10 seconds? The first 7.5 seconds of the echo were obliterated by the last 7.5 seconds of the transmission. So we only heard the last bit of his message in the echo. How was a 10 second transmission ever supposed to work?
It works fine when communicating with another station, just not when you want to listen to yourself.
Wow, sure wish I could have been there! 73 - Dino KL0S
+Dino Papas It really was a fun day!
that's cool!
reminds me of VE3ONT setup !
WAYYYYY cool!!!!
:-) W2MO on 7.163 @1300 that day... Tootles... Wade ( not EME ) :-)
Did anyone calculate the power loss and propagation delay of the moonbounce transmission?
+T Komoski At 1296MHz, the path loss is on the order of 270dB! Propagation delay is about 2.5 seconds, round trip.
Nice event! Some time ago I found that there is a whole movement of moon bouncers: www.moonbouncers.org/ I remember looking at some board schematics from German moon bouncing enthusiasts hoping to lift some ideas for LNA.
Was it only me who noticed that almost all people on that video are 60+ or older?
+Alexei Polkhanov EME is a pretty popular amateur radio activity - we had no trouble making dozens of EME contacts over the course of the morning and afternoon.
:-) W2MO on 7.163 @1300 that day... Tootles... Wade ( not EME ) :-)
+Dwdanieldotdd Yes, we had a couple of HF stations on the air all weekend for the special event.