Keith,
I am not familiar with the ARCS 2 program, except for having found their web site. Perhaps someone else can comment on that part. From the description, it does sound as if SatPC32 is just working the system harder, as it needs to, to deal with Doppler.
Fixing you problem will probably require some experimentation. The easiest is to change the CAT Delay parameter. Try increasing it in steps, or less likely, decreasing it.
Make certain you have the latest drivers. 64 bit drivers are problematic under stress, though they have gotten better.
The Prolific devices are rife with counterfeits using hacked and/or early drivers. Consider changing to a converter with the FTDI chip set. It is fairly common for people to report that solving similar problems.
Erich reads the BB and may have other input.
73s,
Alan WA4SCA
<-----Original Message----- <From: amsat-bb-bounces@amsat.org <[mailto:amsat-bb-bounces@amsat.org] On Behalf Of Keith McDonnell <Sent: Friday, May 02, 2014 8:12 AM <To: amsat-bb@amsat.org <Subject: [amsat-bb] Re: satpc32 Doppler < <I am using a prolific usb to serial port converter which uses <a 64 bit driver. The other control program that I have tried <for the rig is ARCS 2, but of course, Doppler shift is not a <function of this program, but it doed refresh the frequency <display, both by the program, and manual turning of the rig <knob. Thank you, kg2ix <_______________________________________________ <Sent via AMSAT-BB@amsat.org. Opinions expressed are those of <the author. <Not an AMSAT-NA member? Join now to support the amateur <satellite program! <Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb <