Extending a off set dish

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G7JTT
Posts: 115
Joined: Fri Jun 10, 2016 5:05 pm

Extending a off set dish

Post by G7JTT » Fri Mar 01, 2019 4:02 pm

Hi all,
With all the activities on QO100 and the efforts of improving your signal into the satellite. It occurred to me is it possible to extend the size of an offset dish with wire mesh in a similar way that has been done with prime focus dishes? Whilst it's unlikely to be that efficient on 3cm with the right size mesh it should work at 13cm. The other plus point is it's unlikely to offend neighbours or partners so much as a very large dish. So as any one been successfully in extending a offset dish and did it work ?

Cheers John G7JTT

g0mjw
Posts: 789
Joined: Sat Sep 20, 2014 9:15 am

Re: Extending a off set dish

Post by g0mjw » Fri Mar 01, 2019 4:25 pm

You can, the offset is just a section of a larger parabola - bonus the feed does not move which mean my patch will illuminate it better, up to a point, but is there any point, given a 1.2m dish appears already enough?

Mike

G7JTT
Posts: 115
Joined: Fri Jun 10, 2016 5:05 pm

Re: Extending a off set dish

Post by G7JTT » Fri Mar 01, 2019 5:27 pm

Totally agree Mike a 1.2m dish and 30-40W does appear to be good enough to get it but as an amateur you always want something bigger and better Hi and after seeing those 3m dishes being used, it got the "I need one of those" syndrome.! But also realized I'll never get that past the XYL so this was just a thought 😁

All best John and your feed is working a treat thanks 👍

g0mjw
Posts: 789
Joined: Sat Sep 20, 2014 9:15 am

Re: Extending a off set dish

Post by g0mjw » Fri Mar 01, 2019 5:43 pm

You might as well try it at least. Remember errors should be less that 1/10th Wavelength. Extension 20-30cm tops

Mike

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