[time-nuts] Data collection cycle -- multiple sources to one counter?

[David Kirkby]

Poul-Henning Kamp wrote:
> Instead of minicircuits I would be looking for video-cross-bar chips.

Any reason to prefer them over the pin diode or GaAs switches from 
Minicircuits? I must admit to having no idea how they would compare here.

> Maxim as a bunch:
> 
> http://para.maxim-ic.com/compare.asp?Fam=Vid_Mux_Buff&Tree=SwitchMux&HP=SwitchMux.cfm&ln=
> 
> A MAX458 8x4 switch would be able to drive two counters which could
> measure any two of eight sources against each other.
> 
> 	http://pdfserv.maxim-ic.com/en/ds/MAX458-MAX459.pdf
> 
> There is even an eval board which does most of the job already:
> 
> 	http://pdfserv.maxim-ic.com/en/ds/MAX459EVKIT.pdf
> 
> As far as I can tell you could drive it from a parallel port
> with bit-banging.
> 

One thing to note is that Maxim have a *very* nice policy on samples, 
which effectively means for experimental purposes, the chips are free.

Just register on their web site, tick what chips you want (limit of 
about 6 or 8, no more than two of the same type) and they courier them 
to the next day. If you need more than a couple of one type, pick a 
standard and an extended temperature range model, and perhaps a mil spec 
one too. Or order some more the next day.

I don't think you can get evaluation boards for nothing, but I have not 
actually tried.

In contrast, I've always had to pay for Mincircuits bits, but do happen 
to have one of their PIN diode switches sitting around.

-- 
David Kirkby,
G8WRB

Please check out http://www.g8wrb.org/
of if you live in Essex http://www.southminster-branch-line.org.uk/