ASM-1 Life

[Dave Fulton]

On Wed, 19 Mar 1997 gstopp at fibermux.com wrote:

>      It really does sound like a power supply issue, at least so far... 
>      does that HP power supply have a current limit knob? If so, crank it 
>      to max current. There's no problem in doing that, if all connections 
>      are OK. The ASM will only take what it needs.

No current adjustment. And the ASM draws the specified amount of current 
(or close to it) from both supplies.

>      
>      Otherwise, make sure that you're using fairly big wire for power. 
>      Skinny wire carrying current causes voltage drops. Any impedence in 
>      the power lines other than 0.0 ohms may cause circuit interactions. 
>      I've used 24 gauge solid (LAN UTP cable), but it would be better to 
>      use 14-18 gauge if it's handy.

I just used small hook up wire until I was done with the bench testing, I 
will attempt to swap them out with some larger wire.

>      
>      Also - you did include all of the bypass caps, right? They should be 
>      around 0.1uF each, or 0.22, or something larger than tiny and smaller 
>      than huge.

Yes,& this might be where I screwed myself. I used cheap .1uf 50V ceramic 
caps for bypass purposes only. I think this is unlikely but possible. 

I take it to mean that any amount of crosstalk between modules is not the 
norm & all could be removed?

I bussed the wiring between the PCB & Panel(so that it looks neat). It
is possible that I am getting small amounts of crosstalk just within the 
wiring. 

Dave