Moonbounce on 1296

[VK4CDI]

Finally..........
Isolation relay causing a problem, so runnin g direct to preamp (no TX) 13dB sun noise.
Moonset Sat night was like the low end of 20Mx (during sunspot low!!) several CW sigs...then PI9CAM at S6. G4CCH at -12 on JT
Guess RX is FB!!
Sun arvo fixed relay, 12.5dB sun noise, ready to go........
Only problem is PP motor makes a terrible racket at 3am!!!!

Phil VK4CDI

[VK2JDS]

This mornings qso attempt was difficult from this end Phil, I was seeing my own return pings but being through trees is very lossy and would make it very difficult for you to see me.
Today I decided to strip the ldf5-50 out of the dish feed and install a flexible ldf4-50 heliax equivalent for the transmit side.(with a resulting loss in power at the feedpoint)
The septum feed was moving around while moving the dish due to the inflexible nature of the heavy ldf5-50 causing problems at the receive side too. Broken connectors and the new preamp being fitted with sma connectors forced the decision.
Now sma conectors are all good up to 18GHz, but are useless when it comes to any sort of mechanical stress. N to sma adapters just pop open randomly. These sort of connectors are well suited to installation in shack equipment, but are poor in a harsh moving environment out on the end of a dish feed.
again the dural beacon was my friend as i made measurements of what sort of signal i could get from 200 kms away behind a ridgeline (lots of ridgelines actually). i attach some pictures of the various configurations, best was the vlna straight into the septum, 2nd best was the N relay with vlna on a adapter with a flexible heliax to the main cable. the pic of the hardline with small microwave relay was the worst, and the heliax with adapter straight in the output port failed after 5 minutes of rotating the dish back and forth. its due to the rotational force on the heliax even through the clamp. i dont want to compress the cable so its supported in 3 places, but still things break.
in the first picture the heavy black cable from the lower termination on the coax relay goes to a dummy load so the preamp can be easily switched from feed with cold sky to a 290K load.
power measured coming out of the receive port when dumping about 100 watts into the transmit port was about a quarter of a watt so you dont need much of a relay here as long as its extremely low loss.
73's

[VK2JDS]

Heading into winter now and the weather has been very poor over the last 3 weeks or so. Some equipment failures in the hut due to the damp and poor visibility of the moon. Digital elevation meter has been really handy during this weather resulting in contacts into Russia, Bulgaria, England, Netherlands, Japan, Canada, Brazil and California. The local highlights last week have been Doug VK3UM on cw (thanks for putting up with my poor cw rx) and Phil VK4CDI at -30.
Yay Phil, I think with some fine tuning of the dish alignment system there it will improve, but your signal was straight and steady due to that nice new radio.
I have been doing some more sun noise rise measurements and adjustments using NFM. Its a gradually improving station here. Get hold of that program Phil , it will allow you to make direct sun noise rise measurements using the same computer you will be using to decode the signals off the moon. Cant get better than that. It makes it easy by proper measurement what improvement or degradation you are making with each adjustment. I am using it to set the fine adjustment of optimum noise figure by adjusting the input coils of the g4ddk vlna with it all mounted at the feed. :lower the dish on motor drive to stepladder height, open vlna , adjust slightly, close vlna raise up to sun and make a new measurement.
also the pins i am using are about 39mm in the septum and its now achieving 30db return loss on both ports.
Another thing to add is a skirt of about 30cm of bird netting around the outside to reduce spillover.
Keep us posted of your progress Phil
73's de Dave vk2jds

[VK4CDI]

Good stuff Dave, I will check out that software.....
Last weekend, rewelded the El pivot arm, it wasnt mechanically correct. The power supply feeding the 36V linear actuator sags badly,40V down to 22 on load, so need to fix that. I think I have found my low Tx problem! Not enough drive to the SSPA, which is mounted behind the dish. 1W from the TS2000x, through a 20db pad, to give 10mW to the PA. Trouble is a) 20 Metres heliax adds a dB or so, b)TS2000 1W is not exactly one watt.... end result is I am getting 8Watts at the feed. No wonder you were barely copying me.....HP power meter and step attenuator from work should get that spot on!! Az encoder mechanics sorted, need to buy a small Gilmer belt and will have full auto tracking. Hopefully I will be all ready to go for the EOA event.
A couple of piccies on http://www.usq.edu.au/users/moat/photo.htm

Cheers all
Phil VK4CDI

[VK2JDS]

Things are still progressing. Many stations to work on 23cm eme jt65c, every week or so there seems to be a new one or 2, then it goes quiet for a little while as the moons offset 28 day orbit shifts coverage to a different spot.
The most recent interesting station was Felix DP1POL on the German base in Antarctica. He decoded here at -24 quite reliably even though its a 65 element horizontal yagi and 500 watts but he wasnt able to decode me though.
Then Felix had a cable failure as his heliax broke when moving the yagi at -40 degrees C !, now thats cold.

During this coming month there is a moonbounce competition so expect to hear the big boys back on air.
To give you an idea of the signal strengths I worked HB9HAL Christoph at a huge -4 this morning , and he got me at -5. HB9Q is even bigger! and claims he will easily work single yagi stations. Thats a s9 signal on the IC910H - bearing in mind with the G4DDK vlna i have a S5-S6 s meter of noise into cold sky. It was pumping the agc.

It seems nearly every time I turn up in the HB9Q logger on a favourable morning Phil VK4CDI is also there.
His gear is going well and he's working plenty of dx.
We worked a dogpile of sorts last tuesday morning, the Netherlands stations were congratulating themselves in the logger for working us VK's and there were stations spread up the band each 5KHz from 1296.060 to 085. Quite a choice of European stations to choose from on JT65C.
I got a few CW contacts this week as well, so get your speed up a bit as they all like 12+ wpm. (but they tolerate my slower morse hihi).
Matt VK2DAG is gearing up for 13cm and has done some ping tests (which i listened for) so I am hoping he will document his path to eme on 13cm here in the vklogger forum for all to read.

I had a stuck relay and sent 10 watts up the back end of the G4DDK vlna, and also a single stage NE325 backup vlna until i sorted out the problem. they are back on air with new fets and a reset of the bias current and cold sky/290k dummy load measurements over and over tweaking the coils little bit by little bit to get them back honed to exact match for the septum feed. Sun noise rise is now 12.4dB on my 4.6metre on the dual stage and 11.7 on the single stage, 11.3 on the backup-backup single stage(you cant ever have too many preamps ! hihi). If you are in the middle of a great DX contact to some remote part of the planet and a preamp dies , you want to be able to swap onto a good one fast! . Silver plated N bulkhead connectors with vlnas in diecast aluminium boxes are robust and easily swappable and waterproof mounted right at the coax relay on the side of the feed.
all good fun. go and find yourself a unwanted C band dish from someones backyard.

73's from Dave VK2JDS

[VK4CP]

When I finally get enough spare time, I want to be able to sit down, concentrate, and read this topic through end to end.
I really want to give 1296 EME a go, and with the IC-910 purchase earlier this year, I feel I'm part the way there.
70W amp to come next.

Thanks Dave for posting, as your enthusiasm for this has been an inspiration, and I reckon 1296 EME will definately relieve the boredom in between 6M F2 DX!

[VK2JDS]

Hi Adam, I hope you do have a go at it. Its something really astounding when you hear your own carrier reflected off the moon, still amazes me.
7:30pm on the first Friday night of November I am giving a talk at the Orange and districts Amateur radio club (ODARC) about how to go about getting into 23cm moonbounce from a practical point of view. Taking the mystery out of it all, explaining the options about the gear you need and the software, how to run it all and the operating procedures etc. Basically everything I have learnt in the last 5 years condensed down to give others a running start into the mode using dishes you dont have to spend 10 years building from scratch.

This weekend was the ARRL 6,2,70 and 23cm moonbounce competition and wow was the 23cm band alive! There were oodles of high powered CW stations to have a tune past and attempt contacts with.
As usual for us Aussies after the Americans and Canadians loose aquisition there is a 'dead zone' when the moon is a bit either side of north, You get some JA's etc but as it progresses west towards Europe the signals appear again and between 1296.005 and 1296.035 there were CW signals every 5KHz or less. Some with quite noticable drift too. There wasnt much JT65 activity though.
This means for us here with long yagis or small diameter dishes good for terrestrial work the chance to hear dx off the moon, or at least see it with spectran or the waterfall display in WSJT6.
Most of the overseas big stations were active, and of the locals VK3UM, VK5MC VK4CDI were in the thick of it. I had several great contacts on saturday night into sunday morning on CW and JT, but had to work monday and missed the morning European window. But it was K5,W6,VA7,OK1,DL0,SP6 stations I worked besides the locals , missed G4 as the moon set though and there were heaps I didnt get to work as there were dogpiles that I just couldnt get onto due to my power limit of 130 watts.
Doug VK3UM puts up with my 8 to 10wpm straight key CW as usual... I am improving, slowly. hihi
This meant I have now passed 50 different 2way eme station contacts.
You can do this too.
73's de Dave vk2jds

[VK2JDS]

More time has passed , just today Phil vk4cdi worked some americans, a japanese station and myself. His station with a 3.7 metre dish is really working well . and thats just the start of the pass, later tonight europe will open up and the hb9q 1296 logger has a full board of waiting european operators. get yourself a dish and get going on the microwave bands.
today i removed the 60 watt amp and installed the 160 watt amp out into the box on the back of the dish, its only running about 90 to 100 watts but the return echos are clearly audible and bright white traces on the spectrum display. The added choke ring onto the septum feed does seem to better illuminate the C band dish i have here.
the weekend 5th 6th and 7th will see us attempting Brazil on 13cm . Matt vk2dag is bringing his 13cm transverter and PA out and installing it on the dish again here for a sked with Bruce PY2BS. doppler will be difficult and its all cw on the higher bands. Bob vk0bp/vk2abp will be out to observe. Anyone else interested?
my 23cm high power permit application got approved, just waiting on the paperwork now. we now need to convince acma to allow high power permits for troppo long haul work
cheers all, hope to work you off the moon soon
73's de Dave vk2jds

[VK2JDS]

further progress
after blowing up the g4ddk vlna a few times and more spare parts on the way, keeping backup preamps is a priority.
the new incarnation of the G4DDK preamp now uses a MGF1404 gasfet and has been tested down to 0.15 dB.

if you have a G4DDK check this link for mods http://www.vhfdx.ru/apparatura/rw3bp_12 ... timization
check this link for how to measure it http://www.vhfdx.ru/apparatura/accurate ... s_1296_mhz
here is part5 :http://www.vhfdx.ru/apparatura/1296-mhz-small-eme-station-with-good-capability-part-5

Its all about digging deeper into the noise to find those weak signals.

then there is the output power:
fitting the power amp out at the dish makes a huge difference, then I just changed the feedline from the back of the dish up to the septum from ldf4-50 to ldf5-50 and it gave a 20 watt power increase.
its a good option to mount the amp and switching gear at the bottom of the dish mount , but best on the back of the dish itself if you can do it. Run serious hardline up to the septum as it wont be bent and twisted as the dish rotates and elevates, just use superflex heliax from the IC910h to the dish mounted box (or whatever you can get from field days etc)
run dc power to the dish mounted amp, preferably 24 volts to reduce current compared to 12 volts , or just run mains up there and have a switchmode supply with the amp.
i dont have mains power, so 24 volts and a 160 watt amp has worked out well.
73's all

[VK2JDS]

This past weekend saw 4 amateurs and a 'soon to be amateur' come out to the dish to activate the Orange and districts Amateur radio club callsign in the 160 metre transtasman ssb contest. 150 contacts later the contest ended and it was time to work some moonbounce!
We booted up the station the next day and were hearing good echos. For the first time listening to your own signal echoing off the moon is a awesome experience. The look on the face of the soon to be amateur John is worth describing :
I had briefly described to John what I was attempting to do , we could see no visible moon as it was so close to the sun. we used a digital elevation meter and a compass for alignment and i pressed the morse key and the sound coming out of the speaker said it all . He stood there with mouth open for about 15 seconds watching the echo on the spectran screen trying to take it all in. (gobsmacked)

The moon was down in the west and we were into the business end of the pass. After some calling we got JT65c contacts for the visitors into the Netherlands and England!. Smiles all round and the new fellers were really inspired to get cracking on their own stations. Matt vk2dag and Bob vk2abp have done all this before but it still brings a grin to our faces hearing such nice echos , but Steve vk2xde and Lindsay vk2amv were new to the dish here and took it all in.
A great weekend of radio indeed, wire aerial for 160 metres , to a 5metre on 23cm

background to this , while testing the setup and a new interface cable i had a switching malfunction and blew the back-end out of the G4DDK yet again... doh
always keep a stock of spare in and out fets for your preamps, that kept the station going after a fet swap. buy in spares from Sam G4DDK and he is happy to send some, I just got another spare vlna with the new mgf1404 mods. Next was a new(old-but refurbished) dish, 5 metre, for Matt vk2dag to collect. everything is a work in progress, not just the hardware , but the people who come out and have a go and get inspired
73's all de Dave vk2jds

[vk5apn]

Dave

Yes this column is an inspiration. To all those who have thought about it but struggle to start. Yes it is that easy.

Having got my feet wet on 2m with a 10ele YU7EF yagi (5mt boom length) and a DSE amp kit, worked 14 stations so far (JT65b). Google and Youtube my call for my home page and video. This is with no elevaion control. Soon to be rectified, to enable greater flexibility.

I too am looking higher in frequency. Have my eye on a 3m dish (at a very good amateur price - bonus). I think (hope) that is OK with the XYL (Oh and council ). I dare not produce a 5m one Hi Hi.

Make Google your friend. Some interesting sites for 1296 EME include

http://rvhfg.org/pdf/articles/29.doc (intro doc)

http://w7iuv.com/1296eme/7ftdish.htm (Pictorial progress on the cheap - love the "G" clamps)

The only Downside to this EME is that IT IS ADDICTIVE.

So BEWARE

Could imagine the wide open mouths when they heard the echo's. Yet to hear mine, but would be just like my first EME QSO. Pumped and over the moon - HI HI

Regards

Wayne VK5APN

[VK2GOM]

Hi Wayne,

What sort of power level were you running on 2m?

I have had a listen at the moon before, but yet to hear (or should that be see/decode) anything. My local noise is simply too high I think.

I think the record for 2m EME at the moment is something like a 5ele and 5W on 2m! Someone over in Scandanavia completed with one of the big gun stations.

73 - Rob VK2GOM / G0MOH

[VK2JDS]

Hi Wayne, 3metre with shadecloth over it , now tell the XYL thats called a shadehouse for plants !! hihi

hope you get it going soon , its great fun !

any questions please post up here and we will get it sorted

monday morning at 3 am i was up and operational on 1296.065, Israel was -28 through the fog and pouring rain , but no sign of the Belgian station I had a sked with
The Israeli has a 1.5m dish skirted to 2.3 metres and about 40 watts and septum feed. You will have great success with the 3 metre on 1296, and especially on 2.3/2.4 GHz etc
Well worth getting and installing. if its a polar mount then set the elevation to straight up and lock it at that. now use the polar tracking actuator to raise and lower the dish for elevation adjustment , and swing it around on the top of the pole for azimuth. works well

73's from Dave vk2jds

[vk5apn]

Rob

I'm using a DSE Amplifier Kit. As JT modes are harsh (continuous TX of tones etc) on the amp I run it about 80-100w out. I do have a fan ontop of the Heatsink blowing air down onto the amp. This comes on only when in TX. This is fed into some second hand RG213, about 14mts of it. Who knows if it was OK. No mast mount preamp, no GPS lock of the stock IC706MkII (not the G model - said like the TV ad for the yellow pages and the G-O-G-G-O-mobile)

I am lucky in that I do live in a rural township, about 6km (line of sight) from the urban sprawl. When the moon is setting (due to no elevation control here) on the good moon conditions, the time is in the early hours of the morning (1-4am). Most neighbours are in bed with no plasma's or PC's on. The nearest farms does not use electric fences (grapevine growers), so no noise there. Keep trying, as I think you will be pleasantly surprised. Best to pick a good moon weekend. There is a link to the moon condition calendar on my EME log book page. Best ones coming up are early and late Sept.

Dave

Yes having to out bid one of the neighbours to the guy who has the 3m dish to secure the purchase. Comes with mounting pole and actuator. Still in negotiation at the moment. But there is another one that I have my eye on as well, but that is still in the air. Being lazy here in getting the one already dismantled, Hee Hee.

Will keep you informed on the progress, fingers crossed. Well done on the contacts. Yep next to 2m (due to easy access to HPA's and easy build ant that have been computer designed), 23 cms would be the next populated band. According to others and to the word doc link in my last posting. But that may change as the HPA's are becoming easier to obtain as well as the TVRO's Dishes.

Regards

Wayne