Receiving 10 GHz EME with a small dish and LNB
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- Опубликовано: 11 окт 2024
- You can receive 10 GHz EME with a simple setup. I used a 76cm satellite TV dish with LNB, RTL-SDR stick and software. In this video I discuss the dish setup, using a stock LNB, modifications for better frequency stability, automatic tracking of doppler shift with WSJT-X and HDSDR, and early results with this system.
I should have mentioned aiming a dish of this size on 10 GHz is critical. The 3 dB beam width is about 2.6 degrees. In practice I find that if I aim it slightly "ahead" of the moon in its trajectory across the sky I get consistent signal for about 5 minutes, then it starts to drop off. I move the dish every 5 minutes.
In the video I mention KA1GT's notes on modifying and using the Avenger LNB. Here is a link to that:
bobatkins.com/...
Link to my 10 GHz Notes and progress page:
www.n1bug.com/1...
Very impressed by your approach to EME monitoring. This is achievable by most Hams who want to expand into EME in small steps. The RTL-SDR, 25mhz source and filter resolves a lot of mysteries for most of us and doing this successfully without an AZ-EL tracking mount removes a lot of the financial intimidation as well. Bob Atkins laid out the way and you put it into an doable thing. Well done.
Thanks for the very kind comments. Decoding and hearing EME signals on 10 GHz was a huge thrill for me. I hope others might enjoy it too.
4 rolls of desolder wick on the wall. You are the master of the airways.
When you work on everything from old tube radios to tiny SMD stuff, you can never have too many sizes of solder wick. 🙂
@@n1bug i always runout on this wick.... you can never have enough :D
I really enjoyed 5.7 and 10 gig ten years ago. I was roving back then in ARRL vhf contests. A local ham who had much more knowledge than I, built up several 10 gig stations and mine was a rover unit. It was a 3 watt Downeast Microwave transverter with a Yaesu 817 as the IF unit. Man, on a good hill top you could really qso long distances. The rain scatter in the summer weather season was really fun. 73 de AF4OD
I am working on building a terrestrial 10 gig system for my tower. I have a DB6NT transverter, choice between 2W and 15W amp, Downeast Microwave preamp, a 2 foot Radio Waves dish and feed. I need to get it all together and work out how to power and control it. 375 feet of wire from the shack is really not an option due to voltage drop. I'm thinking battery and solar panel on the tower but still need to figure out control.
Greetings from Peru (western) Maine FN44tl! I just found this channel. I've heard of your call sign and read some of your articles. I've enjoyed them. Thanks for the great video!
I'm glad you found it interesting. I have another video on how I adjust for the polarization of EME signals and will be doing one shortly on how to measure sun, sky, ground and moon noise with this setup.
Awesome work Paul. Looking forward to your completion of the terrestrial system
Thanks Peter. Me too!
Great video, I subscribed, and look forward to seeing what you do next
Thanks! Further EME experiments are on hold pending some means of aiming a bigger dish. I have a number of other 10 GHz projects going, including getting the dish I used for these EME tests onto one of my towers so I can try to hear some terrestrial signals.
I have a challenging research project to suggest. Taking a TV Remote and the sensor from a broken TV and using it for communications. Use part of the remove to send the comm signal instead of the digital code that controls the TV function and modulate it for Audio or digital voice or FSTV. Reverse the process from the module removed from the TV.
I haven't personally tried it myself but I bet someone has. There are quite a number of people who are using LEDs (visible and IR) and lasers (gas and solid state) for communication with Morse code, audio, or data. I haven't followed it in a while but years ago I was in a very active online group of experimenters using light communications.
Great work. Very nice. Not requiring a track mount is awesome, ill likely use one anyways for longer recieves between adjustments
I would like to have a tracking mount but every solution is very expensive. It is the way to go if you can do it.
You peaked my interest on this. I've always been curious and I think I have almost all the pieces to play with it. I'll have to come up with the LPF on the GPSDO but most everything else I have. 73's and thanks for the video.
Good luck! Normally I would build a filter but I didn't seem to have the right capacitor values and I was in a bit of a hurry to try this out.
Really cool video, thank you, sir!
Thanks, I am glad you like it.
Great video. I have a 7.5 foot umbrella dish. Would like to set it up for EME next summer.
Good luck with your project! I'm going to guess the umbrella dish will not have sufficient surface accuracy for 10 GHz (I could be wrong) but it will surely work well on lower bands.
@@n1bug Going to try 1.2 ghz. Seems like popular band for eme
@@wireworks616 Yes it is a very popular band and your dish should do very well there. I have a 10 foot dish in storage which I would like to use on that band someday.
Oh you got me all in great content!
Thanks. I have been busy with other things but more coming soon.
Brilliant, just the information I was looking for, from dish construction to clocking a bullseye LNB and so much more. Thank you for this video . G1ORP
I'm glad you found it helpful. There is another video in the series, about polarization of10 GHz EME signals. I will be doing one on how to measure sky, moon, sun and ground noise with this setup when I get some time.
Great video! Look forward to hearing you on 10Ghz. 73 de BA4TB
Thanks. I hope so some day, lot of work and very expensive for me.
Very exciting stuff, though setting up the software and the GPSDO and filters with all the other work is probably far away for me with my budget and disability
My hands shake too much. Can't say I haven't dreamed about doing EME, Sattelites and all that microwave stuff. Very advanced and way more intriguing than HF radio. Thanks, Craig
I love a good adventure and this has certainly been one. I would have had a hard time with the budget if I hadn't already had the Leo Bodnar GPS unit from past projects (2200 meters). Good luck, I hope you can try it someday. I have a 1.8m dish that was given to me which I would like to use for a 10 GHz EME station but aiming a dish that size is no easy task! I have no idea how I am going to do it on my budget.
Great detailed and clear video. Thank you!
Thank you!
When you make a Moon Bounce be careful not to aim the beam direct into the eye of the man in the moon.
I always wanted to try them bands but its very expensive but very interesting 👍⚛
Yes, very expensive which is what kept me from trying it in the past.
Thats cool you can see the doppler move or drift off the moon is moving
Yes it is very interesting. I had prior EME experience on 144 and 432 MHz where the doppler is very slow and doesn't move as much. At 10 GHz it is really something to see!
You are using a trick to sight the dish that we use in Astronomy all the time. Great idea!! However, yours is an offset dish. How do you account for the offset angle? Using your sight you can only align the back of the LNB.
It isn't visibly obvious in the video, but the boresight tube is aligned parallel to the radiation axis of the dish. This is done by peaking the dish on sun noise and then adjusting the angle of the boresight tube left/right and up/down until the tube casts a symmetrical shadow. Once that is done... if the dish is peaked on signals from the moon, the moon appears centered in the tube when you sight through it.
@@n1bug Doesn't sound right to me. You would still NOT be looking at the sun. The shadow would be minimal when the tube is aligned - agreed. But you are using the boom of the dish to align with. That boom is not placed symetrical with the center of the dish but rather offset by NNN degrees. I agree that the LNB would be aligned but not the dish. The dish reflects signals at an offset angle. Simply pointing the LNB arm to the source does not produce a proper alignment. Try it. Align the LNB to Jupiter and then try to listen to the Jovian whistles; you'll get nothing!. Its more likely that the incoming signal has a significantly wider beam width than the offset of the dish. In this case "near enough is good enough". Own a 3D printer? There are many solar alignment tools available on Thingiverse for you to print - many for satellite dished. Make one and see what you get.
Excellent video!!
Thanks!
How much is a proper tracking system? Everyone is saying it's expensive, but how expensive exactly?
The least expensive off the shelf solution I can see that MIGHT be adequate for even a small dish like my 76cm would be about 2800 USD - the Sub Lunar SDD-3 / Green Heron RT-21 Az/El combination. The strength of such a system is not needed but tracking precision is. Most rotators cannot point precisely enough. A dish this size is 3 dB down at 1.2 degrees off target. It needs to be pointed within half a degree or so for reasonable EME success. If you have a machine shop and you are good with microcontrollers and precision position sensors, you may be able to build something for less money. I do not know if even the Sub Lunar / Green Heron combination has the precision required for a more typical 10 GHz EME dish such as the 1.8m I have in storage. That would need to be pointed even more precisely as it would be 3 dB down at 0.5 degree off target. I suspect the difficulty of aiming a dish precisely enough keeps a lot of people off 10 GHz EME. I have everything required to put my 1.8m dish on EME except for that.
Well done! 73's de LA3EQ Jan
Thanks Jan, good to see you here.
Howdy from KT1R.
Howdy Lou!
You sent me down a rabbit hole... lunar libration, Cassini's laws.... etc... I had no idea the moon did that or that the effect would be pronounced enough to cause significant doppler shift in a signal. I guess (?) a scientist could use the signal drift to find the actual change in lunar distance over time...
I'm sorry about the rabbit hole. It happens! There are lots of interesting phenomena happening with EME. All of those parameters are of course related. We do it the other way around. Software calculates lunar distance and motion in real time, from which the signal frequency shift is calculated.
@@n1bug Mind if I ask you another question? How difficult is it to get into terrestrial 10GHz? I guess you can't use commercial LNBs like the one you show, because they are receive only and might be set to the wrong part of the 10GHz spectrum for ham radio 10 GHz terrestrial (?). I guess you need a transceiver LNB, a transvertor from uhf to/from 10GHz, and I guess feeders/waveguides and stuff like that. Any ideas here?
I welcome questions. It is not difficult. A typical terrestrial setup would be an 18 to 30 inch (45 to 76cm) dish, either offset (like the TV dishes, which work fine) or prime focus (where the feed goes directly in front of the dish center), a feed horn of some type, and a transverter mounted just behind or below the dish, connected by the shortest possible run of coax or waveguide. Receive preamplifier and higher power transmit power amplifier can be added. All of these items can be purchased new. Deals on used stuff come along occasionally but demand is often high. Most 10GHz terrestrial is portable operation because you need an unobstructed shot at the horizon for most contacts. It is difficult for many to get that from a home station. In my case I will be putting my terrestrial system on a tall tower to operate from home.
You are correct that the TV LNBs aren't really useful for a transmit/receive system. They are optimized somewhere up in the 11+ GHz range. A likely guess would be around 11.75 GHz. They are not optimum for 10.368 GHz receive-only either, but this is largely offset by having no lossy feed line. The probe in the feed horn is directly connected to the LNA (preamp). Some have torn the guts out of LNBs and converted them to plain feed horns for transmit/receive use, but I will leave that to those with better rest equipment.
ICOM Japan, have out the Ic 905 that will have 2 Meters 70 Center, and 2.4 and 5 Ghz, and yes 10 Ghz band,
can this setup be used for radio astronomy?
I'm not very knowledgeable about radio astronomy but I would say no. With a dish of this size on 10 GHz, the whole sky appears very quiet, so I don't think you will receive enough radio noise from specific sources (other than the sun) to be useful for that purpose.
goot lern chenas and mach-more.😌tenks.
Very interesting presentation 👍⚛
Thanks, glad you found it interesting.
Hi. I am in the process of building a copy of your system to Receive WSPR moon reflection and have two silly questions that I hope you can give advice on.
1. Which version of the windows operating system are you using?
2. I can locate WSJT-X but not a copy of WJT-X-10 G can you help with the location of source of that.
Many Thanks and regards
Rob (GW0FJV)
Hi Rob.
1. I am using Windows 10 Professinal 64 bit, but any recent version should work fine.
2. I'm sorry if I was confusing. You just need a recent version of regular WSJT-X. As long as it included the Q65 mode you are all set. I forget in which version that mode was introduced but it has been there for a while. There is no special version for 10 GHz.
Good luck with your project and let me know if you need any other information or assistance. I will do my best to help.
@@n1bug Hi again, and thanks for the info. I do have a question that perhaps you could help with I attempted to set up but when I came to set up the radio selection in WXJT-X. I had no option for the Kenwood 2000 series radio. So as that option available in your WSJT-X or did you somehow add it to the selection.
Thanks again Rob.
I apologise it is there! My eyesight failed me.
@@robertlang641 No need to apologise! My eyesight fails me frequently. I'm glad you're making progress.
Hi again getting a bit confused here I'm wondering how to correct the HDSDR frequency for the LNB I know about the manager button and that throws up a frequency but how does one correct for the 9750 Mhz frequency shift to match the dongle frequency Or am I missing something really obvious. Secondly I'm wondering what software you use to send the output from HDSDR to WSJT.
Thanks in anticipation.
Rob.
Very nice!! Tnx for the video. 73
Thanks for watching!
I have never looked at radio, signal or whatever videos and now theres 4 (including this one) in my recommendations. What is going on.
I'm sorry, I have no idea. I don't know the details of how RUclips selects videos to suggest. I get recommendations unrelated to things I have watched also. I suspect everyone does.
If you find an old sliding saucer that would work great i remember them snow sleds.
Possibly but it has to be almost a perfect parabolic curve. I haven't checked any of them but I doubt they are a true parabola. The higher you go in frequency, the more accurate it has to be. What will work for receiving relatively strong terrestrial signals may not for EME signals which are much weaker.
Cool, and very interesting. Thank you!
But why does every video from the USA pronounce solder as sodder?
There's a letter L in there folks!
I don't know. It has been pronounced that way over here since long before I was born!
Did ya happen to notice that American English, Australian English, Canadian English, New Zealand English, Cockney English and London English all pronounce things differently? Do yo pronounce ought, brought, sight, bright the way they are spelled? Why do Canadians say ewt and aboot instead of out and about? And if English is a Germanic language, why did they completely eff it up?
Is the power limit is 10 watts just like to know
You can run as much power as you want up to the legal limit of 1500 watts, but power is very expensive on this band. Solid state amplifiers can run from around $350 for 3 watts to $4000 for 50 watts. There are few (very few) surplus TWT (Traveling Wave Tube) amplifiers around up to 500 watts but few are lucky enough to find one or be able to afford it. The smaller EME stations have 10 to 15 watts.
@@n1bug wow i thought it was only 10 watts yeah thats why i didnot get into that band it is very expensive now you tell me its it's legal limit and the amplifiers are extremely expensive dam well i will still stick to what i have 👍💯⚡
@@Atomshamradio I was fortunate enough to pick up a 15 watt amplifier for about $325. It is a surplus amp out of some kind of digital data radio system that has been retuned to our frequency around 10.368 GHz. It should be enough to some EME if I can get my 1.8m dish (which I got for free) set up. The problem with a dish that size is aiming it accurately enough! That is a whole other can of worms, but I'm thinking on it.
The old dishnetwork dishes will work⚛📻
Yes. That's another thing I should have mentioned in the video. I spent three months looking for one, but never found any that were available.
GREAT FANTASTIC VIDEO LOVED IT. GREAT HELP FOR LEARNING EME. 73S wb7qxu
Thanks, glad you liked it.
Next step: transmission ;-)
I wish. :-) 10 GHz EME is a dream I had for many years but is extremely expensive. Maybe someday I can do it.
thanks for the very interesting video. hope to see you off the moon 73 on5gs dirk
I hope some day I can be QRV.