[amsat-bb] TranSystem / Meyers Dish mounting

[Bill Howell <bhowell@xxxxxxxxxxxxxxx>]

On my Meyers "dish", I drilled out the rivets that secure the 
dipole-mounting-bar
to the front of the dish.

The remaining mounting-bar _clamp_ (still attached to the front of 
the dish), fits the
TranSystem downconverter mounting piece pretty well (with the help of 
a hose-clamp).

BUT... the original Meyers dipole was about 14 inches from the dish face.
On the newly mounted TranSystem downconverter / dipole, I measured about
10 inches from dish face to dipole.
I would think that this new distance would not be ideal.

Using the local MDS transmitter as a signal source, I manually held 
the new dipole at
the 14 inch mark.
What's interesting is that the TV picture did not perceptibly improve 
when moving the dipole from
10 inches, to 14 inches from the dish face.

The only reasoning I have for this is that the MDS xmtr is so strong 
that it makes
dipole location not-so-critical.

My next step is to position the dish across the back yard from my 2.4 
gig source
(50mHz-into-diode multiplier), and perhaps more easily fine-tune the 
dipole position.

I've printed out the weekend pass predictions for AO 40 and hope to 
hear something with this lash-up.

Does anyone have any experience tweaking a dipole position at this frequency?
Should I expect the sweet-spot to be broad or sharp?



Bill Howell
University of Texas at Austin
College of Fine Arts
Office of Computing Technologies
N5ALO  Amsat 32459  QRP-L 415
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