[R-390] 400hz converters

[Bernie Nicholson]

A few years ago I got very much into ARC58 /TRC75 and after using all sorts of aircraft alternators that sound like a 747 on full boost ,I found that there is a product desighned for running motors at variable speed I contacted the company and recovered 2 systems from their rubbish bin and made a good system , briefly it consisted of a ring counter driving some large transistors and was single phase input and 3 phase out put at at 4kva, it generated a multi stepped square wave that after filtering was  compatable with the gear and was permanently set to 400Hz, it ran here for many years with no problems , preceding this I was using a PP2352 unit that ran on 28v dc and was one of the most unreliable pieces of electronics that I have owned, it used to generate internal spikes and was always blowing the big germanium power transistors which were individually fused and would gradually die , the motor controller was a great improvment, I am sure they have them in the states HI