I think the last ones made were the mark IV which was a major change,
it was the Eagle with the digital TRANSISTOR front end. Marks 1 to 3
are TUBE (ok, there are two little metal can transistors in the back,
but I think they were just for power rectification) Radios. Thats why
almost everyone thinks of the Mark III Golden Eagle as the top of the
line. The Mark IV was buggy because of the major changeover in design.
I've never heard of a Mark V, but if it existed, it would be
transistor'd with all those funky scanning options, but it should
perform more like a Mark III since Browning would have gotten the bugs
out by then. But then I've never heard of a Mark V so I don't think
any were ever made. Only IV's. BTW: There's a pot in the transmitter
near the Modulation tube that can be adjusted to control the level of
modulation. Since most Eagles are run with the cases open for air flow
(or just unscrewed for quick access) Its easy to use this bias control
to adjust the percentage of modulation instead of buying one of those
microphone add on boxes. Overmodulation is one of those touchy areas
that most fools dive into headfirst. Properly used, it can make an SSB
signal (or AM if you're really good) stand out during extreme Dx. The
tradeoff is that nearby & moderately distant stations hear you like
garbled mud. Replace the Browning Mike with a D104 (Crystal Head)
& you've got a radio that can walk on water with only four watts.
klaatu