[Elecraft] K2 with rigblaster

[Joe Subich, W4TV]

On 2015-06-16 1:29 AM, Jim Brown wrote:
> FWIW, I have no use for the dedicated ham interface boxes no matter
> whose name is on them -- the wiring interface for the ones I've seen
> are an invitation to RFI and hum/buzz problems, and most have Pin
> One Problems. A very good USB sound card can be bought for $70 (see
> the ASUS U5 Zonar), You can build a WinKey for about $75, or the
> Yankee Clipper SO2R box for about twice that cost. A serial to serial
> cable is two connectors and some CAT5. Serial to USB adapters are
> inexpensive.

That's all well and good for someone with your experience and retired
with time on his hands.  However, when one counts the cost of all the
individual *kit* pieces - $300 to $400 - add USB to serial converters
(even though inexpensive they add up), a proper FSK interface like the
K0SM or K8UT devices, includes the time to build/integrate everything,
and then troubleshoot the interactions, the cost of dedicated ham
interface boxes is very reasonable for a single box, plug and play
solution.

The pin 1 problems go back to the transceiver - there isn't a single
amateur transceiver (that I know of) that properly bonds *all* signal
returns to the chassis.  Most of them don't even have a metal chassis
any more and many of those that do use non-conductive enamel or power
coating that prevents proper bonding in the first place.  Everything
is mounted on circuit boards with several inches of traces before the
return signal actually reaches the chassis (if it ever does).

Once the transceiver builds in a pin 1 problem, there is very little
that an interface - yours included - can do to solve the issue.  One
can only use balanced connections, twisted pair cables, isolation
transformers and bonding to minimize the problems.  Add the tremendous
lack of understanding about common mode RF (RF on the outside of the
feedline) and complete ignorance issues of high current returns (TX
current returning to a common power supply via accessories) and it's
a wonder that most amateur stations don't have wore problems than they
do.

73,

    ... Joe, W4TV