[hpsdr] Atlas slot positions

[Murray Lang]

Hi all,

I'm stepping outside of my comfort zone here, but it's bugging me enough 
to risk looking silly or covering old ground.

I gather that the slot position dependencies are the result of data 
pulses bouncing backwards and forwards along the atlas bus. Is this 
right? In other words the bus lines are transmission lines and the 
reflections are the same as we'd see in an unterminated RF transmission 
line (standing waves and all). Yes?

Can we apply the same solution to Atlas as we'd apply to our 
transmission lines and apply a correct load or termination? This could 
be tested by putting a waveform generator on just one of the lines and 
trying a termination at the end or ends. An oscilloscope would reveal 
the difference. If it's effective then a card could be built with 
nothing but terminating resistors for placement in the end slot (or 
maybe both end slots?). Is the impedance of the bus is already known? At 
at any rate the best termination value could be found by trial and error 
pretty quickly, if indeed this is effective at all.

Just a thought.

Murray - VK6HL