[Elecraft] How 'bout a USB interface?

[Mike Butts]

I'm surprised no one (that I've noticed) has raised the primary
objection I'd have to USB in the K2: RFI!  USB is much faster
because its signals are in the HF range with faster edges.

Wayne and Eric went to quite a bit of trouble just to keep
the RS-232 clean.  First page of the KIO2 manual:

"RS-232 interfaces are often significant sources of RFI 
(radio frequency interference), which can degrade
receiver performance. This is because most RS-232 driver 
circuits use a 20-200 kHz square-wave RC oscillator to 
generate the negative DC voltage needed for signal drivers. 
To minimize RFI, the KIO2's serial interface provides an HF 
crystal oscillator (operating well outside of any ham band) to 
generate the negative driver voltage."

After all the work it took to clean up my house (alarm system,
network, dimmers, etc.) my choice is RS-232, no USB thank
you very much.  An FCC Class-B qualified RS-232-to-USB
adapter at the far end of a serial cable is the best answer
for USB in a high-performance HF radio.

I'm just now soldering in the RF Board relays on my K2 #2640.
What a delight this is to build!  And I already have several
mode projects in mind for the future (like an AM detector
for SWL).  Thanks everyone!

  73 de KC7IT