[Amps] 30S1

[Bill L. Fuqua]

I recently acquired a Collins 30S1 amplifier. I am very impressed by its design and performance. It exceeded my expectations due to the fact that the only information I had was the spec sheets which were apparently developed to be compatible with the Amateur Radio Service Rules in the 60s.  It is very linear up to past 1500 watts output and only requires 50 watts drive which improves the linearity of my transceiver. 
   The "Load" meter setting is very interesting and allows one to observe the linearity of the amplifier by comparing the input drive voltage with the plate RF voltage. It also takes out  some guess work in how to best load the amplifier.  It has loads of interlocks and protective circuits which you will never find in todays amateur radio products. Ther is practically no grid current drawn by the screen grid and none by the control grid. Which adds to its linearity as well. And then there is the RF negative feedback which along with the natural negative feedback that comes with cathode drive that improves the linearity as well.  
   I am impressed. It is a keeper.

73
Bill wa4lav