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Re: Working AO40 with portable station ?

With your >1m dishes the norsat should hear ok.  I'd recommend just buying a 
preamp instead of a whole converter if you want to save some money.  I do 
pretty well with the old DEM preamp (self-biased LUA design, not state of 
the art anymore) and a Drake 2880.

25-50W into a linear 11 element 70cm will trip LEILA for me when squint is 
reasonable, that will give you an idea what is necessary.  If you have +40 
dBm (10W) available at the antenna with about 1.5 dB less gain (than the 11 
ele), and from above, +46 dBm (~50W) into the 11 ele is needed to trip 
LEILA, this implies you would be 7 dB or so down from my portible station 
which was quite workable.

This means in some cases your SSB will get into the bird and be 
understandable and some cases it wouldn't.  CW would work for sure.

Assuming you don't want to buy/lug around a 70 cm Brick amp, my suggestion 
would be to try to increase your antenna to either 14 elements linear, or 
better 7+7 RHCP. (Antenna gain is much cheaper than power)

Since you like building antennas, look at the Kent Britian WA5VJB "Cheap 
Yagis".  I used a 11-ele of this design, and I'm working on the 11+11 
element design RHCP.  They work fine, are easy to build, light and can be 
redesigned to break down into several pieces.  I've been using a cheap 
camera tripod for that antenna up until now.  I suspect with a little 
tweaking ABS or PVC could be used for the boom and the whole thing could 
just "push" together.

For a picture of a linear "cheap yagi":  
http://www.fredspinner.com/W0FMS/rubeao40.html

Also look for the "cheap yagi" page on my "fredspinner.com" site and in 
google for other sites (some better than mine) to get dimensions.

Fred W0FMS

>From: "William Leijenaar" <pe1rah@hotmail.com>
>To: amsat-bb@AMSAT.Org
>Subject: [amsat-bb] Working AO40 with portable station ?
>Date: Mon, 01 Apr 2002 23:08:03 +0200
>
>Hi AMSATs,
>
>Today I was listening again to AO40, and I did some tests with 70cm uplink.
>What I findo out, and also see very often on AMSAT-BB is that uplinks on
>70cm are in the range of 20W to 50W.
>
>I have here an 2m/70cm back-pack station, and I want to upgrade it with 
>13cm
>RX to work via the AO40. The station has only 10W PEP, with an 7 elements
>yagi. I have only an deaf NORSAT convertor for now, but I am wondering if
>this will be enough to work via AO40, and if I can hear my signal back with
>an KUHNE 13cm RX convertor and 80cm dish ???
>
>I'm just an student, and its a big cost when I buy it and find out in
>practice that it does not work.
>
>73 de PE1RAH, William
>
>
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