Re: gEDA-user: Clearing mask to mount shields

[Dan McMahill <dan@xxxxxxxxxxxx>]

Darrell Harmon wrote:
> I went with 1 via every mm. So far, I have 2110 vias, so I should be able
> to stay under 2500 by the time I finish routing it.
> 
> I created a footprint by drawing the lines and vias on the board, and then
> selecting all the parts of the shield box and creating an element from it.
> It worked fairly well. I had forgotten that selection in pcb has been fixed
> and I could hold shift and select one piece at a time. That is why I was
> looking for some other way. Thanks for all the help. I will post pictures
> and of course design files when I get this finished. It is a DC to 1.8 GHz
> spectrum and network analyzer. Unfortunately, it is not very reproducible
> due to some of the parts such as the YIG oscillator and the bandpass
> filters which were machined from blocks of copper.
> 

sweet!  I can't wait to see it.  Does this interface with your SBC?  I'm
curious as to what sort of design tools you used for the bandpass
filter.  I did quite a bit of work many years back on a filter design
toolbox for matlab which I really need to pick up again and release for
octave or scilab.  Too many projects, not enough time...

Did you buy the YIG oscillator as a canned block or did you manage to
buy a YIG resonator and design an oscillator around it?

How do you do the sweeping?  Is it PLL controlled or more of a free
running  deal like the plugins for the old HP141's?  If it's free
running, do you have one of those "lock and roll" loops?

You don't have a tracking generator to go along with it by any chance do
you?  Actually I guess you did say network analyzer.  Is it a vector or
scalar analyzer?  Reflected as well as transmitted response?  Full two
port?  Supports the full 12 term calibration?

How's your front end sensitivity and dynamic range?

Do you by any chance have the phase lockable 10 MHz reference I/O like
many HP boxes?

I guess I should just wait to see the design files as that will answer
most of my questions.

-Dan