Is a foxtel ofset dish usable for 1296Mhz?

[VK6TU]

I have just got a poratble ofset sat dish and am wondering if it is suitable for 1296Mhz
or should I stick to a high gain vertical and posibly a couple of Yagies?

I also have got a 1.7 M dish could this be suitable to 1296Mhz also?

Thanks

73 from Michael
VK6BHY
NWWA

[VK2XSO]

2.5 wavelengths is the lower limit where a dish starts to work.
So for 23cm, (lets round it up to 25cm) then a 60cm dish is barely useable.
On top of this you only have a very small aperture because your feed is at least 12cm of that 60cm, though because these dishes are usually an offset, the feed does not obscure part of the dish. There however is a small loss on one polarity over the other for offset dishes. It's usually trivial, but I'm not sure how this effect relates to frequency if at all.

Quite simply there are much better antennas that offer much better gain and performance for 23cm than a small dish.
There's no real advantage to using a dish for 23cm unless the dish size is bigger than about 1.2m.

Depending on the polarity you want to use, double diamonds, 8 over 8, phased arrays, yagis, loop yagis, quagis and helicals all offer better performance for directional antennas. Commercial verticals are still the best choice for omni directional vertical polarisation.
I've tried a few well known designs and all have failed miserably. Only one design which is a common 6dBi mobile antenna configuration I've had any success with.

Bang for buck, a helical antenna is the best. Easy to make, costs almost nothing and offers circular polarisation (good for 23cm).
8 over 8 is next. Cheap to build, but difficult to get right and make work well. It can be directional or omnidirectional, but it's horizontal polarisation.
Double diamonds are extremely tollerant antennas. Relatively easy and cheap to make and almost impossible to get wrong. (linear polarisation)
Loop yagis are also easy to make. They take a little bit of skill to put together, but can be made broadband enough to cover the entire band. (linear polarisation)

Yagis are harder to make for 23cm. They tend to be more narrow band, so using log period feeds and careful choice of elements helps keep them broad band enough that they don't need to be tuned.

Quagis are harder to make, but they're more tollerant with bandwidth.

Dishes, well there is only one rule when it comes to dishes for 1Ghz to 20GHz. BIGGER is ALWAYS better !
Solid dishes don't offer much of an advantage at 23cm, but you can find ex-telstra grid pack antennas for damn good prices. The smallest are about 1.2m and the largest are 5 metres. They're rated at 1.5GHz and often work up to 2.4Ghz. (the 800MHz version aren't good for higher than 1.3GHz) They can be used for 23cm, but have a reduced efficiency.

The best part is they are light, have low wind ratings and if you cover them with wire mesh, they're good to 6GHz.

[VK2KRR]

Hi Michael,

What do you want to use the 1296 frequencies for ? Local chatting or long distance etc? SSB I pressume?

Your use and expectations will really govern whats suitable and whats not. Although in answer to your first question, a Foxtel type dish is probably not much good for 1296 as the gain would not be as good as a decent yagi.

[VK6TU]

Thanks for the quick replies,
Some good info, looks like it is not worth keeping so will find a new home for the dish, it came with a nice portable stand
I do have a 1.7m solid dish wonder if it is worth hanging onto that

I plan on moving South next year and will be on a nice high spot near Dunsbrough, Have got a Icom 910 with the 1296 module, long distance could be a option if I can setup the right antennas, am looking at my options for when I set up a new station
I should be able to make up a few suitable antennas, got access to some good scrapp Aluminium, just need to work out what I will need

73 from Michael
VK6BHY
NWWA

[VK2KRR]

Michael,

Sounds brilliant! I have worked VK6JR on 2m from there. I'd like to make it on 432 and 1296 also. So if you have the station in a good spot then we just need the right conditions

The Foxtel dish would work good for 10 GHz. If you have the room it might pay to hang onto both the dishes, you never know what bands u may end up looking at.

You could use the 1.7m solid for 1296. It just depends what gain and beam width your happy with, and what you have available to mount the thing onto. Obvoiusly the bigger you go, esp solid, the more its going to catch a lot of wind.
On 1296 here I run a 12 ft dish (about 3.8m). Its mesh. Its great for DX has a very narrow beam width of 5 deg or so.

Myself and im sure many other operators in the east will hope to see you on 2/70/23 soon!

[VK2XSO]

Yep, hang onto the old foxtel dish. You'll find a use for it.
http://home-and-garden.webshots.com/pho ... 1318UkjavJ
They're certainly useful for one thing or another.

[VK6TU]

Thanks for all the feedback, looks like I will have to find a way to get te 2 dishes South next year.

Want to setup a nice station once we get a house built, hope to be able to setup something for 2m, 70cm and 23cm, got a IC910 with the 23cm module
in a few years you may hear me across the bite.
Our block is not very far from VK6JR but we are near the top of the hills, with a good view out to the East, one of the reasons for getting the block, nice high location

73 from Michael
VK6BHY
NWWA

[VK2KRR]

Michael,

Sounds great! I cant wait.

All my antennas should be set up how I want them by then also.