[BC] Re: Unique VP-50

[DHultsman5@aol.com]

In a message dated 1/2/06 8:38:09 P.M. Central Standard Time,  
Xmitters at aol.com writes:

I heard,  but not sure, but the VP-50 may have been Hilmer Swanson's first  
transmitter project when he thought, why do we have to keep building AM  this 
way 
and he dreamed up PDM while on his lawn tractor mowing his lawn.  The VP-100 
which was one more cabinet wider than an MW50, was the first  PDM Harris 
transmitter 100 kW. I also heard that the VP100 (not the  VP-100A) that was 
the 



The PDM/PWM  idea was developed at Collins by Warren Brene in a  government 
project called Tacomo.   One of the engineers on the  project was Hilmer 
Swanson before Harris. The PWM patent was held by Warren  Brene and Collins.  Hilmer 
Swanson was the first to use it as an AM  modulator at Harris with a patent 
PDM.   When Collins did their "Power  Rock 5" transmitter the "PWM" patent 
number was used as a basis for the  development.  It stood thru the patent reviews 
instituted by the PDM  folks.  Hilmer Swanson was probably the best broadcast 
transmitter  design engineer of recent times.
 
Dave