I have a friend's BlackCat 1000W HF Linear Model JB2000/10-80 (w/a pair
of 3-500Z Tubes) that was manufactured in or near 1976. Unit is strapped
for 120v operation.

Some random pics - http://www.vambo.org/pictures/BlackCat/

I've recaped the unit with higher quality electrolytics and replaced the
HV diode stack with diodes of higher voltage and current ratings. I've
also installed a 20ma relay keying circuit in place of the automatic
power detection circuit. The tubes are the original and *may* need
replacing but it still was able to produce over 400watts of AM power with
acceptable harmonics. One of the tubes looks gassy when under load.

I'm not going to try and tell you this is not a POS but it is a working
linear that has been rebuilt that has some life left. It's a great way to
put yourself into a linear cheaply. I will not ship this unit but I am
willing to help deliver on the front range of Colorado or part way for
the surrounding area. $250 firm