Re: [amsat-bb] G-5500

[Paul Williamson <kb5mu@xxxxxxxxx>]

At 4:20 PM -0500 12/8/02, Joe Cutchin wrote:
>Any ideas? The "voltage adjust" figure which should be around 250-255
>when running rotator setup under Wisp, both for el and az is unstable
>and fluctuating. It is not staying fixed at 254.Thus rotator is jerking
>and not stable either.I'm learning to hate Yaesu rotators.

First find out if it's the rotator's fault or not: look at the actual 
voltage on the connector (without your interface connected) and see 
if it's fluctuating. I would tend to doubt it, unless you have 
something broken mechanically. It would be normal to see a variation 
of one count (253 and 254 or 254 and 255) regardless of how perfect 
everything is. On a typical system of this type, I wouldn't be 
surprised to see plus and minus one or two counts of variation, or 
more if it's very windy. That should be considered normal, and the 
interface (or the software behind the interface, depending) should 
take that much variation into account.

You didn't mention what interface you're using, so it's hard to 
suggest a procedure for that. If you see a steady voltage on the 
rotator box but still see a lot of variation in the sense value 
returned by the A/D converter, then you might be seeing noise or RF 
interference getting into the A/D converter. Adding a bypass cap or 
other filter might help.

If small variations in the A/D value are causing your motors to be 
activated, look for a hysteresis or "dead zone" setting. This might 
be hardware or software, depending on your interface. The dead zone 
should be big enough to prevent that kind of erratic behavior.

73  -Paul
kb5mu@amsat.org
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org