[WriteLog] USB -> RS-232 device noise

[Ken Widelitz]

I just bought a Byterunner USB -> RS-232 adapter to give me a serial port on
my laptop. This is a model with a single serial port on a dongle. Every time
Writelog polls the radio via the W5XD Multi-keyer, I hear a bzzzzt in the
audio. The cable on the adapter goes to the PC side of the Multi-keyer and
another cable goes from the Rig side of the Multi-keyer to the radio. 

If I hook the PC up directly to the radio, there is no bzzzzt. If I listen
to the radio via its headphone jack, there is no bzzzzt. I have put LOTS of
ferrite on the cable from the PC to the Multi-keyer, but no joy. The PC DB-9
is right next to the received audio in to the Multi-keyer, so it appears
that is the interference source.

Any suggestions?

73, Ken, K6LA / VY2TT