[Hpsdr] Call for Comments - ALEX

[Phil Harman]

Hi Chris,

Thanks for the feedback - reply in the text below.

73's Phil...VK6APH

>
> If this is going to be hand built with hand made toroids it would be
> good if there were some kind of self diagnostic designed into the
> system.

Yes, that is how we plan to test the filters.  The Mercury/Penelope
combination will form a spectrum analyser + tracking generator.

>
> I'm surprised there is no A to D converter in the forward and reflected
> power level signals.  You have SPI going in.  Would be easy to send
> these back also over SPI.  a 10-bit serial ADC would be more than
> good enough for this.  Sending the signals back as analog allows for
> noise to find it's way into the long wire.

The ADC is on the Penelope board.  We will have a couple of log
amplifiers on Alex to bring the FWD/REF signals up to a higer level and
drive the cables at a low Z.  That way I don't think noise will be a 
problem.
If we run full duplex then an internal ADC would be active on Rx and
we are keen to keep any clocks external to Alex.

>
> How about some LEDs?

LEDs are good! I have some on the preselector I use with the prototype
Mercury receiver and as you say they are very useful.



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