[Elecraft] K2: USB to Serial for Rig Control

[David Fleming]

Is the noise constant or only when the software is polling the radio?  I had a noise problem when I had my software polling every 200ms. I would get a 5Hz hashy buzz at about S-2  with no antenna attached. With an antenna the noise would fall into the noise floor. I'm now polling every 1 second so the noise, while still noticable, is not significant. And not even noticable while operating unless the band is very quiet.
   
  -David W4SMT

JT Croteau <jt.n1ese at gmail.com> wrote:  Several folks recommended bargain USB to Serial adapters that are
based on the ProLific chipset. So, I figured I try one out... for $9
what the heck. It works fine for both rig control and CW/PTT keying.
HOWEVER, it is a big noise generator. Holy cow. My S-meter jumps by
2 points when I insert this device into the USB port on the front of
my PC. I have yet to try connecting it to one of my rear, motherboard
mounted, USB ports. I'm hopeful it will help but not counting on it.

Check out this waterfall display and you can clearly see where the
adapter is inserted.

http://tinyurl.com/2hzyl3

I think I will end up investing in a multiport serial adapter for my
PCI slot instead. heh.

-- 
JT Croteau, N1ESE - Manchester, NH