Difference between revisions of "Using ex-satellite dishes"
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Online calculator to find the feed point of an offset dish: http://www.satsig.net/pointing/finding-dish-offset-angle.htm | Online calculator to find the feed point of an offset dish: http://www.satsig.net/pointing/finding-dish-offset-angle.htm | ||
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| + | Excellent article by Paul Wade W1GHZ on using offset dishes http://www.w1ghz.org/antbook/chap5.pdf | ||
http://www.satsig.net/22-deg-offset-dish.htm | http://www.satsig.net/22-deg-offset-dish.htm | ||
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==Feeds for dishes== | ==Feeds for dishes== | ||
| − | Excellent design for 3.4 and 5.6GHz by Brian G4NNS: http:// | + | Excellent design for 3.4 and 5.6GHz by Brian G4NNS: http://brcg4nns.org/FeedHorn.html |
http://www.w1ghz.org/antbook/conf/dualband_feedhorn.pdf | http://www.w1ghz.org/antbook/conf/dualband_feedhorn.pdf | ||
Latest revision as of 12:59, 19 November 2019
Your local household waste disposal area (tip) is a great source of parabolic dishes which are very usable on the microwave amateur bands - and it's environmentally friendly to re-cycle them!
The picture shows a recycled Sky mini dish being used on 5.6GHz - the feed is a WA5VJB log-periodic PCB feed http://www.wa5vjb.com/products1.html – these are available in the UK from G4DDK. http://www.g4ddk.com/Prices.html (see the 5.6Ghz wiki page for more details)
Finding the feed point
The easiest way to find the feed point is just carefully replace the LNB with the feed or replacement LNB in exactly the same position. However this is not always possible - but luckily there are a great number of pages on the web showing how to find the point:
Online calculator to find the feed point of an offset dish: http://www.satsig.net/pointing/finding-dish-offset-angle.htm
Excellent article by Paul Wade W1GHZ on using offset dishes http://www.w1ghz.org/antbook/chap5.pdf
http://www.satsig.net/22-deg-offset-dish.htm
http://www.john-legon.co.uk/offsetdish.htm
http://www.ntms.org/files/Nov2015/Fun_with_Off-set_dish.pdf
This page has a calculator for parabolic dishes (not many of those at your local tip): http://www.qsl.net/pa2ohh/jsparabolic.htm
Feeds for dishes
Excellent design for 3.4 and 5.6GHz by Brian G4NNS: http://brcg4nns.org/FeedHorn.html
http://www.w1ghz.org/antbook/conf/dualband_feedhorn.pdf
http://www.w1ghz.org/10g/dualhorn.htm
10GHz feed horn for Sky Dish made using standard UK copper plumbing bits: http://www.g3pho.free-online.co.uk/microwaves/horn.htm