[NLRS] Taking the plunge

[Donn Baker]

Hi John,
Welcome to 10GHz !  It'll be fun!!

Re: the 10GHz feed and your Dish Network dish.  The DEMI feed is in the
class of "Chaparel" (sp?) feed, and MOST LIKELY is for a "deeper" dish than
the DSS dishes tend to be.  That it, its optimized for at an F/D ratio of
about 0.4.  The DSS dishes actually have an F/D ratio of closer to 0.7.
Bottom line is that its NOT a good match.  Will it work ?  Sure.  Is it as
good as it can be ? No.

You didn't say if you have the feed assembly that originally came with the
Dish Network dish.  If you do, there's a good chance that it can be
modified to work as the feed for 10GHz.  This is best, as it already is in
the proper position, etc., and you don't have to screw around with much of
anything.  

Even if the original feed can't be made to work, making an appropriate feed
is realtively easy.  Check out Paul Wade's "Online Antenna Book," chapter 6
(I think).  Its something like "Offset Feed Dishes," or so.  There is an
appendix that deals strictly with DSS dishes, and may even have the
DishNetwork one as an example.  Even if its not an example, using Paul's
software to print a template for the proper horn to illuminate that dish is
easy.  Cutting the sheet brass and making the horn is easy.

Also, talk to Jon, W0ZQ.  I think he has one of those, and maybe able to
offer some advice.

73 Donn
WA2VOI/0


At 17:39 20-03-04 -0600, John P. Toscano wrote:
>I've decided to take the plunge and invest in a 10 GHz tranverter 
>system.  I checked out the latest offering from Down East Microwave, and 
>it appears that they have a new model of their 10 GHz system that is all 
>in one box with 2 watts of output and an improved NF of < 1.5 dB, and 
>that is the model I've decided to get.
>
>http://www.downeastmicrowave.com/PDF/PDF10368.pdf
>
>I will need at least a little help in getting it all on the air.  I 
>already have an 18x20" Dish Network offset feed dish.  Does anyone know 
>right offhand if this dish is well-matched to the feedhorn that is sold 
>by Down East?
>
>http://www.downeastmicrowave.com/graphics/10GFEED-L.jpg
>
>If it is, I will probably just buy one of those when I'm buying the 
>transverter.  If not, then I guess more fabrication is in order.
>
>Take me off the "probable" list for the Lake Superior expedition and put 
>me on the "yes" list.  Being a fat old guy, I would probably do better 
>on the Michigan side of the lake, but it looks like we have a lot more 
>people voting for that side than the North shore, and the best score is 
>to be had if we get a proper balance between the two sets of operators. 
>  So I will volunteer for the North shore as long as I can hang out with 
>someone with some real experience.
>
>On a related topic, I think I'm going to wait a while before trying to 
>tackle 24 GHz.  But some of you are already there, and I saw an item 
>that might possibly be of interest to you folks:
>
>http://www.downeastmicrowave.com/Surplus2003.HTM
>
>A very short way down the page, near the end of the Amplifiers section:
>
>mm-Tech Inc.  24 GHz power amplifier.  0.5 Watt and >45 dB gain.  DEMI 
>surplus, "many" available at $75 each.
>
>Pictures:
>   http://www.downeastmicrowave.com/graphics/a023a.JPG
>   http://www.downeastmicrowave.com/graphics/a023.JPG
>
>For more info:
>   Contact W2PED directly @ pdrexler@hotmail.com
>
> From what I have seen on the SSBUSA web site, 500 mW is a "lot" of 
>power on 24 GHz.  Their DB6NT power amplifiers come in sizes of 50, 80, 
>300, 500, and 1000 mW, at prices ranging from $295 to $1199.
>
>73 de W0JT
>
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