Alan, VK2ADB wrote:
"What sort of feed warrangement did you use?"

600-ohm open-wire line. Many of the rhombics I erected were made from
U.S. Army WW-2 Signal Corps kits. These used three cables in the diamond
shaped curtain which came together at the end supports but were spread
apart by several feet at the side supports. This construction tended to
further reduce impedance variations as frequency changed. We didn`t
bother with this refinement with receiving antennas.

Actual antwenna driving point impedance tended to exceed 600 ohms so
width of the attachment point to the anteena was wide for the cable size
to appear as about 800 ohms and then the spacing tapered steadiy down
during the descent to the horizontal transmission line which was spaced
for 600 ohms.

The cable used in the kits was made from (3) AWG 12 Copperweld wires
twisted together. There was also stainless steel wire for a dissipation
line at the far-end of the rhombic. We had to replace this with larger
wire as we were broadcasting with 100 KW transmitters, far more power
than anticipated by the Signal Corps. Under some conditions and at some
frequencies, it is possible to dissipate up to 50% of the power fed into
the rhombic in its dissipation line.

It is possible to operate without a dissipation line or resistance. The
rhombic becomes bidirectional without the termination. I know from
experience during a period when the Signal Corps dissipation lines
melted from the broadcast power and our fan mail came from South America
as well as Central Europe.

Best regards, Richard Harrison, KB5WZI