I've recently obtained a FunCube dongle and I'm able to get to the weather satellite frequencies (just below 1.7GHZ) for the first time. However I don't have any antenna for that frequency rage (I have a quadrifilar helix for 137MHz that works well) and I'm looking for suggestions as to a type of antenna that I can build (using a "simple" toolkit) for about that range.
I've looked at the price of commercial satellite dishes and they are really out of my range (for now). Also they would be useful for the GOES satellites but not the POES ones (I don't have a rotator nor the roof access etc).
I have also considered getting a cheap GPS antenna (plus LNA?) but they all seem to have a fairly narrow bandwidth and are tuned a bit low (just under 1.6GHZ).
Any suggestions?
Thanks
Susan
Suggestions for DIY antenna for 1.7GHZ
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VK2GOM
Re: Suggestions for DIY antenna for 1.7GHZ
Hi Susan,
A lot will depend on the polarisation of the signal from those satellites. Are they circularly or linearly polarised? A QFH as you probably already know is circular polarisation.
You can certainly build a QFH for 1.7GHz, but it would be fairly compact! A bit of brass strip might work nicely to make one. The satellites themselves often use QFH antennas for transmit.
Also, are the satellites geostationary or orbiting? Obviously for orbiting you will need to follow them, where an omnidirectional antenna like a QFH would be great. A dish would mean some form of pointing is required.
73 - Rob VK2GOM / G0MOH
A lot will depend on the polarisation of the signal from those satellites. Are they circularly or linearly polarised? A QFH as you probably already know is circular polarisation.
You can certainly build a QFH for 1.7GHz, but it would be fairly compact! A bit of brass strip might work nicely to make one. The satellites themselves often use QFH antennas for transmit.
Also, are the satellites geostationary or orbiting? Obviously for orbiting you will need to follow them, where an omnidirectional antenna like a QFH would be great. A dish would mean some form of pointing is required.
73 - Rob VK2GOM / G0MOH
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VK2XSO
Re: Suggestions for DIY antenna for 1.7GHZ
QFH has my vote too.
The use them in modern radiosondes.
You could easily build one with some thick copper strands striped out of some heavy duty power cable.
A Minikits 23/13cm LNA would do the job nicely with a minor mod.
The use them in modern radiosondes.
You could easily build one with some thick copper strands striped out of some heavy duty power cable.
A Minikits 23/13cm LNA would do the job nicely with a minor mod.
Re: Suggestions for DIY antenna for 1.7GHZ
Hi Susan, I am just wondering if the bandwidth of the Funcube Dongle is sufficient to receive the weather satellites on 1.6GHz. I do not know what the bandwidth is for the GOES reception. From what I have managed to read, HRPT reception requires something like a 2MHz bandwidth for the low orbit NOAA satellites. I would have thought the GOES/POES would be around the same. I have not heard of anyone trying to copy such images sofar with one. I could be wrong but I suspect the 80KHz bandwidth from the Funcube Dongle is too small.
Next point is they are out a fair distance so a high gain antenna and presumably LNA would be required I think. Probably why all such ground stations, I have seen on the web, use a dish for weather sat reception at those frequencies.
As I said before, I don't know for sure so just throwing this out there. Hopefully I am wrong and if you are successful update this thread and tell me. Then I might have a go with my Funcube Dongle.
Next point is they are out a fair distance so a high gain antenna and presumably LNA would be required I think. Probably why all such ground stations, I have seen on the web, use a dish for weather sat reception at those frequencies.
As I said before, I don't know for sure so just throwing this out there. Hopefully I am wrong and if you are successful update this thread and tell me. Then I might have a go with my Funcube Dongle.
73 Phil...VK6ADF
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VK3ANZ
Re: Suggestions for DIY antenna for 1.7GHZ
Thank you all for your comments.
Sounds like a QFH (or perhaps a spiral???) will be the next project.
Phil - thanks for then "heads up" on the bandwidth. I had not thought of that as I've seen quite a few references to using the FunCube dongle for the weather satellites - but looking now they all seem to be the 137MHz signal. Looks like some "experimental fun" coming up!
73
Susan VK3ANZ
Sounds like a QFH (or perhaps a spiral???) will be the next project.
Phil - thanks for then "heads up" on the bandwidth. I had not thought of that as I've seen quite a few references to using the FunCube dongle for the weather satellites - but looking now they all seem to be the 137MHz signal. Looks like some "experimental fun" coming up!
73
Susan VK3ANZ