ES-Hail2 / QO-100 project
This page was last updated : 12-Jul-21 10:04:01
Fellow ham Jan PA0JWZ asked me if I was willing to be his sparring partner for a new hamradio project : he wanted to get up in frequency and go for the ES-Hail2 / QO-100 satelite. Because I was thinking about doing the same, I allready started with the RX of the QO-100, the answer was of-course YES.
All information is based on our experiments without any guaranty. Well that's what hamradio is all about isn't it ?
The downlink
Basically for the Downlink all you need is :
- a satelite dish (40cm is enough to listen)
- a LNB (PLL with crystal but one with a TXCO is better)
- a Bias-T to power the LNB
- a SDR receiver like a RTL-SDR or the better ADALM Pluto SDR
- sofware to control the SDR receiver (Gqrz when you use Linux or SDRConsoel when you use Windows).
I already had a ADALM Pluto SDR which I use for measuring and experiments, so the information below is based on that SDR.
TODO : add more text and experiment description.
The uplink
After looking at various possibilities to got on the QO-100, we decided to go for the AmSat-DL UpCon6W. A 70 cm to 13 cm up converter with a integrated 6W PA. Jan ordered one and after 2 weeks it was dropped of by mail.
And we started to collect parts for allowing the up converter to be installed as close a possible to the dish.
The diecast IP65 aluminium housing got a base place on which we installed a large block of aluminium on which the up-converter was mounted.
In a tin housing we placed the bias-T to feed the LNB. In my workshop we drilled the holes for the 2 SMA/N bulkhead adapters, the 2 F connectors and the gland for the 12 - 13.8V power cable.
2 long semi-rigid coax cables I had laying around where modified to fit and connect the up-converter to the SMA/N bulkhead adapters.
Unfortunately I didn't make a lot of photo's of the building process, but in the picture below the final result is shown.
The uplink 2.4 GHz Helix
Jan decided to go for a Helix antenna for 2.4 GHz. Images below shows his first prototype. A 6 turn Helix for 2.4 Ghz. Due to lag of other material, Jan used black plastic but black most of the time means carbon (bad material for antenna design) and a short microwave test showed the presence of carbon (it got warm).
But it was good enough for making a construction over the LNB.
W ordered dome white nylon for the final prototype.
First "field" test.
it was time to see how well it worked in the field.
With this antenna we made our first over the ES-Hail2 / QO-100 bird.
More helix experiments
Another experiment. Used white PVC tubing and coated the helix with liquid rubber. Strangely enough it almost didn't effect the SWR.
The final design.
4.5 turn helix with a white nylon holder.
The SWR plot of the antenna in "freespace"taken with a NanoVNA V2.
For the cover Jan found a PET jar on the internet and ordered a few to see if that worked.
In the final construction the SWR was around 1.2:1 (forgot to take a screenshot).
Installation time
On a sunny monday in September it was to finalize the QO-100 uplink / downlink hamradio setup. Meaning get on roof of the house of fellow ham Jan PA0JWZ, installing the AMSAT DL Up-Converter and the satellite dish to the chimney.
Installation marks the end of 6 months of experiments and a few garden tests. Let's see how it works out in the outdoors.
The final construction of the Helix antenna and the LNB. Yes we are aware that the LNB feedhorn and the TX antenne aren't in the same place.
How well does it work when LNB feedhorn and TX Ant is not in the same place? When we set the beacon 59+20 in the water val display and key down (cw) our signal on the water val display is 59+10. So strong enough to have a good QSO.
Some final tests to see if we have the bird correctly lined out.
The content of the outdoor up-Converter box.
Everything tested and ready to use.
Final photo before we go down....
to the shack of Jan PA0JWZ.
We tested the up- and down-link and we could hear our own signal very well. Also on the WebSDR we had no problem copying our signal. Unfortunately it wasn't that busy on the bird and I had to go.
Later that day Jan dropped off a few parts and told me that he made a few QSO's on the bird. The only problem he had was a little drift in the RX path. So that could be the LNB of the Adalm Pluto drifting. From another OM I heard that with SDR Console software it is possible to compensate for the drift by monitoring the left (lower) beacon. How this is done is described on this page from sdr-radio.com. After that RX drift wasn't a issue any more.
But like Jan said, hamradio is all about experimenting and there is always room for improvement.
Jan PA0JWZ SK
Mid December 2020 Jan called me that I couldn't visit him because he and his XYL got infected by Covid19. At 31 December we had contact to wish each other and familes a good and healthy 2021. But in the first week of January Jan was hospitalized because the Covid19 infection was getting worse and fought for his live. On 6 February he lost this battle and passed a way.
— .- -. / .–. .- —– .— .– –.. / … -.-
Jan PA0JWZ SK.
The day after that, his XYL asked me to come to the closed memorial service to give Jan his final salute. Meeting the family under those sad conditions I offered to arrange all the administrative task regarding the hamradio domain. And that when in time needed, I would help the family with removing the antennas, cables, masts etc.. A offer she and her family (there are no other OM's in the family) gladly accepted.
Tearing down, cleaning up, but . . .
After a few storms and some static on the antenna cables, the son of Jan contacted me, that is was time to take down the antennas etc and asked if we could set a date to do so. That day would become 30th of May. A day as warm as the day we installed the dish on the house of Jan.
We started with thee and coffee and talked a lot, cached up on the last months and speaking about memories of Jan. After that we went outside and stared by disconnecting all the cables, removed the antennas and removed the dish and masts from the house. We lunched together again talking about memories of Jan and after that we cleaned out the shack (removed the antenna and power cables). Luckily Jan wasn't a collector OM so after sorting it was only crate of parts and experiments. As a mall altar to remember Jan's beloved hobby, we put his beloved rig with a table microphone, his morse paddle, his note pad with his final notes and a few unwritten QSL cards on his desk (Jan didn't really have a shack in the traditional way). We took time to let it all sink in, and his XYL and her son wanted me to have the crate and the QO-100 setup. There where no Hams in the family and they would like to see that Jan's last experiment would continue. I told them that the honer would be all mine and instead of continue building my own QO-100 setup, I would be using Jan's setup and continue experiment with it to improve it. That way Jan PA0JWZ ham spirit is kept alive.
Jan it was a privilege to know you, not just as a fellow OM, but also as some one you could talk with about everything else.
I'ts my honor that I had you as a friend, and even a bigger honer that you called me yours.
a project continues . . . .
After a few weeks I decided to setup the dish temporary in my backyard and made some cables to wire every thing up.. Due to the off focus helix position the signals where a little bit weak in SSB on the QO-100 and other operators told me that the signal was readable but not that strong. So that was one thing to start with and the idea a of a new Helix feed was born.
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