I get quite a few emails from readers of my blog asking how my QO-100 satellite station is put together and so, I thought perhaps now is a good time to put together an article detailing the complete build.
My QO-100 satellite ground station is built around my little Icom IC-705 QRP transceiver, it’s a great little rig and is ideal for the purpose of driving a 2.4Ghz transverter/up-converter.
Of course all the software used for the project is Opensource and freely available on the internet.
The station comprises of the following building blocks:
To get a good clear view of the QO-100 satellite I have the dish mount 3.2m above the ground. This keeps it well clear of anyone walking past in the garden and beams the signal up at an angle of 26.2 degrees keeping well clear of neighbouring gardens.
The waterproof enclosure below the dish houses all the 2.4Ghz equipment so that the distance between the feed point and the amplifier are kept to a minimum.
The DXPatrol amplifier is spec’d to run at 28v/12w or 12v/5w, I found that running it at 28v produced too much output for the satellite and would cause the LEILA alarm on the satellite to trip constantly. Running the amp at 12v with a maximum of 5w output (average 2.5-3.5w) is more than enough for me to have a 5/9+10 signal on the transponder.
The large 1.1m dish gives me quite an advantage on receive enabling me to hear the very weak stations with ease compared to other stations.
The photo above shows the 2.4Ghz equipment mounted in the waterproof enclosure below the dish. This photo was taken during the initial build phase before I rewired it so, the amplifier is shown connected to the 28v feed. To rewire the amp to 12v was just a matter of removing the 28v converter and connecting the amp directly to the 12v feed instead. This reduced the output from a maximum of 12w down to a maximum of 5w giving a much better (considerate) level on the satellite.
It’s important to keep all interconnects as short as possible as at 2.4Ghz it is very easy to build up a lot of loss between devices.
For the connection from the IC-705 to the 2.4Ghz Up-Converter I used a 7m run of
LMR-400 coax cable. The IC-705 is set to put out just 300mW on 144Mhz up to the 2.4Ghz converter and so it’s important to use a good quality coax cable.
Once again the output from the 2.4Ghz amplifier uses 1.5m of LMR-400-UF coax cable to feed up to the 2.2 turn Icecone Helix Antenna mounted on the dish. This keeps loss to a minimum and is well worth the investment.
The receive path starts with a Bullseye LNB, this is a high gain LNB that is probably one of the best you could use for QO-100 operations. It’s fairly stable frequency wise but, does drift a little in the summer months with the high temperature changes but, overall it really is a very good LNB.
The 12v feed to the LNB is via the coax and is injected by the Bias-T device that is in the radio shack. This 12v feed powers the LNA and associated electronics in the LNB to provide a gain of 50-60dB.
From the Bias-T the coax comes down to the NooElec SmartSDR receiver. This is a really cheap SDR device (<£35 on Amazon) based on the RTL-SDR device but, it works incredibly well. I originally used a Funcube Dongle Pro+ for the receive side however, it really didn’t handle large signals very well and there was a lot of signal ghosting so, I swapped it out for the NooElec SDR and haven’t looked back since.
The NooElec SmartSDR is controlled via the excellent Opensource software GQRX SDR. I’ve been using GQRX SDR for some years now and it’s proven itself to be extremely stable and reliable with support for a good number of SDR devices.
To enhance the operation of the SDR device I have added a Griffin Powermate VFO knob to the build. This is an old USB device that I originally purchased to control my Flex3000 transceiver but, since I sold that many moons ago I decided to use it as a VFO knob in my QO-100 ground station. Details on how I got it working with the station are detailed in this blog article.
Having the need for full duplex operation on the satellite this complicates things when it comes to VFO tracking and general control of the two radios involved in the solution and so I set about creating a QO-100 Dashboard using the great Node-RED graphical programming environment to create a web app that simplifies the management of the entire setup.
The QO-100 Dashboard synchronises the transmit and receive VFO’s, enables split operation so that you can transmit and receive on different frequencies at the same time and a whole host of other things using very little code. Most of the functionality is created using standard Node-RED nodes. More info on Node-RED can be found on the Opensource.radio Wiki or from the menu’s above.
I’ll be publishing an article all about the QO-100 Dashboard in the very near future along with a downloadable flow file.
I’m extremely pleased with how well the ground station works and have had well in excess of 500 QSO’s on the QO-100 satellite over the last last year.
More soon …
Well as you know the bands have been fairly poor so I have no stories to share with you about “Rare DX” and even my Parks on The Air (POTA) activities have been less than usual.
A while back I did post about the “New” Xiegu X6200 and how it looked impressive “on paper” and was waiting to get more info before making any opinions (good or bad) on the unit.
Above picture from Xiegu website.
Well the X6200 is now available for sale and from some actual dealers rather than the usual Chinese companies…
The information I comment on today is from the Waters & Stanton website who are selling the unit in the UK….
The prices I quote are from their website including their estimation of Duties and Taxes in Canadian $$$.
The price of the radio is 795.00 in Pound Sterling and from there the websites calculates the following…
So if you take in the above sub totals it looks like the converted price of the radio is $1389.70 (CDN) then you add the Duties and taxes of $226.73 (CDN) giving a total of $1616.43 (CDN)
But remember the disclaimer from above:
The estimated duties and taxes are based on CA$1,389.70 of product and may fluctuate due to changes in currencies, shipping costs, clearance fees or how the items are classified by customs. Duties and taxes may be collected upon delivery of the items.
So at this point I am guessing (yes guessing) that the retail North American Price will be fairly close to the above price in the range of $1600 -$1700 (CDN) but remember that is my “Best Guess”.
From what I can see of the details of the 6100 they will be in competition with the ICOM IC705 and the ELECRAFT KX3.
Lets see the reviews that should be available on YouTube very soon and then make your decisions from there.
If it is as good as it seems… It still could be a contender in the upper end of the QRP rigs.
73bob
Disclaimer: This post is me thinking out loud. I am not recommending or endorsing any of the products listed above. I believe that you if you are thinking of purchasing one…. That you should do all your research and draw your own conclusions before you buy one from whatever source you choose.
Its all up to you.
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