Douglas Meade wrote:
 
> I picked up a couple of HA4000's recently, having only seen them
> before in pictures.

Other have pointed out that these are indeed thickwire ethernet
transceivers, but...

I have (in the distant past...) been able to convert these things to
thinnet transceivers. 

Short version:

Take some BNC chassis connectors (female) and solder a short piece of
(insulated) wire to it. Then solder the connector to a piece of copper
pipe, roughly the diameter of thickwire. Take two of these things,
solder the wires to each other and to the spike, then clamp the two
things to the transceiver

Make sure there is no short between the wire and the copper pipe.

Use normal thinwire 

I guess the radio picked up some interference, the impedance was
probably not exactly 50 ohms, but it connected about 4 SUN/2
workstations to a SUN/3 server and a PDP-11/34. (as I said, distant
past...)

-- 
Alex

Replace bitbucket with anything else.