Moonbounce on 1296

[ZL1TPH]

I also look forward to trying out my upgraded system with circular polarization on terrestrial DX during the coming summer season, running higher power and improved receive gain compared to my last 25 or so years using the previous setup.

Me too Ross, others in ZL also .. don't remember any 23 cm contact (ZL/VK) so far this year .. mind you this year is not over yet! I'm watching carefully around November / December for starters ..

And congratulations for 23 cm EME at 5.3 km (SP) to young Mark VK2AMS .. I take my hat off to you both for that one !!

All the best from ZL...

Steve, ZL1TPH

[VK2DVZ]

Me too Ross, others in ZL also .. don't remember any 23 cm contact (ZL/VK) so far this year .. mind you this year is not over yet! I'm watching carefully around November / December for starters ..

Well Steve, it is only October and we made it across the Tasman today on 23cm as well as 70cm and 2m. Your 23cm signal was great to me at S7 on 23cm ssb. A bit later on when you were running your CW keyer your 23cm signal peaked at S8, as shown on this part screen grab from the video I took.

It was not EME, but is probably more of a challenge as troppo only happens some times where as EME is more predictable and achievable more often. It proved to me that circular polarisation is good for ALL contacts, as expected.

Thanks for your portable efforts over the past 2 days - much appreciated.

[VK2DVZ]

An EME update....

Having made my first 23cm EME contact on 17-5-2012, when I worked Ian VK3AXH (when I was running low power), I have today reached a personal milestone with contact No. 100 being added to my log, by working Gabriele IK5VLS before moon set this morning.

My small station EME setup has worked well. The only change I have made to it during that time was to increase my TX power to give me 120W at the feed.

I have learned a lot but there is so much more to learn especially about improving my operation technique.

There are lots of physical obstacles in the form of trees, power lines, my own towers and antenna arrays that all manage to 'get in the way' when I want to try and work a station either soon after moonrise or before moon set, depending on the AZ/EL position of the moon. If the station can't be worked at that time, one hopes that will be on again another day when the moon is in the clear.

Family commitment often restrict or impede my operating time, but even so, any contact is better than none at all 'off the moon', so I consider myself fortunate to have had made that many contacts to date. Thanks to all for taking the time to work my small station - much appreciated!

[VK2AMS]

Congrats on the 100 ross! you have dissapeared in a cloud of dust(moondust that is)!! well done.
best 73 . mark VK2AMS

[VK5TX]

What is the min power for EME?

Will 60 - 70 watts be enough?

Ben

[VK2DVZ]

Ben,

My initial contacts were made using my 2.4m dish and about 35 Watts at the feed.

There are many large stations who are capable of working very low powered callers, as they are doing most of the work. If you have 60-70 watts, give it a go. You will be pleasantly surprised.

I look forward to working you in the future Ben, off the moon!

[VK5RC]

Hi All
I have been slowly plugging away at a "portable"EME station as the only place I can get a good shot at the sky is in the driveway!
A 3m dish f/d=0.38 (measured), VE4MAsuper (using 7"diam stainless steel flue pipe and a large baking tin!) feedhorn (return loss 20dB), a G4DDK LNA.
Today I took some Sun Noise measurements, slightly below the 11dB predicted from VK3UM's lovely program EMECalc (thanks+++ )
I used a Funcube Dongle Pro with a homebrew (5MHz wide 1296MHz Centre) band pass filte,r as a temporary receiver, using Spectrum Lab.
The Red trace below is the average noise
From 0216 to 0218 Dish pointing at Sky ~-129dB
From 0218 to 0220 Dish pointing at Tree (about 25C temp) - 127dB
From 0220 to 0226 Dish Pointing at Sun -122dB
Also some picks of the setup.
Any comments/suggestions appreciated.

[VK5RC]

A PS , a picture of the dish prior to mounting the feedhorn (and testing for optimum position).
The dish is mounted on an engine stand so can move relatively easily, actuators for Azim (120degree) and Elev (100 degree)

[VK4CDI]

Nice one Robert....look fwd to working you soon...

Where did you get the big cake tin?


73

Phil VK4CDI

[VK5RC]

Thanks Phil
My morse is pretty awful so I might be a while!
The cake tin I got off eBay, Cake Tin Round 16" x 3" for about $26 including post. I have used quite a few dissimilar metals so it can't be left out in the weather.
73 Rob

[VK2JDS]

Hi Rob, it looks good and i like the cake tin idea, sure beats rolling up one using aluminium sheet hihi

What sort of radio do you intend using?
The program NFM from Owen Duffy makes a handy sun noise rise measuring tool, definately worth installing on your laptop there, and as it uses the audio from the actual rig you will be transcieving with, the results will give you a good idea of how well its working.
Another good one is spectravue. It has continuum mode, which allows you to do fft averaging and resolves down to 0.2dB per division if you want to look for other sources besides the sun.
I have a FCDP here and it drifts etc, not something i would use for decoding with, more suitable for just keeping an eye out across the eme segment of 1296 looking for signals. The 910 does the main work.

Let me know if you want a signal to test it with, remember there is a beacon on 1296.000 when the moon is setting. Best to wait till the declination favours the north to listen for it though. ON0EME is its callsign.
73 from Dave vk2jds

[VK5RC]

Hi Dave,
The cake tin was a brilliant idea of my 11yo daughter who looked over my shoulder at a picture on the internet of a complete VE4MA feed in COPPER (aaarrggghhh, how much would that cost!)
For actual EME Rx I plan to use my Icom 910H with VK3HZs excellent XRef installed with an external OCXO (which is pretty stable). Thanks for the heads up re Owen Duffy's program and the beacon. They sound very useful.
I have heard of Spectravue but not tried it yet, that averaging function sounds useful but even in my driveway over a few (5-10) minutes you could see the effect of no automated tracking on noise measurements, with noise levels drifting down a dB over 3 or so minutes. I think that may be added a bit later once I get the basics going. Inside the PA/sequencer box I have an arduino (for display control at present) which I could use for some simple tracking later on.
For Tx side of things I am using W6PQLs 150W PA sequenced with a MiniKIts sequencer.
Thanks for the offer of a signal and appreciated comments.
73 Robert VK5RC

[VK4GHZ]

Greetings.

I am considering a W6PQL MRF13750 LDMOS based 600 W PA for 23cm EME.
This should offer the ability to coast along at legal limit.

Have spent many hours trying to find suitable high-power relays, but availability seems limited, and therefore expensive.

It appears the following might be suitable:
• Dow-key (Transco) 402 series (just!)
• Dow-key (Transco) 402A high power series
• Transco 800 high power series
• Transco 11300 (the 'Y' relay)
• Ducommun 2NH series

Any others that should be considered?

Other than eBay, have already searched extensively, can you suggest a source (that actually has these in stock)?

And yes, I'll be using a septum feed for the EME work (with the obvious separate TX & RX paths), but also want to be able to use this PA for terrestrial activity as well.

[VK4CDI]

GD Adam,
What about the Russian relays? Should handle the power OK, but isolation probably ordinary.......


Phil
VK4CDI

[VK4GHZ]

I ended up buying a pair of Transco 11300 relays.
The infamous "Y" relay.