[TenTec] Ten-Tec 411 Centaur Amp Problem

[Dr. Gerald N. Johnson]

Art Collins did NOT design the 30S-1. At the time it was designed he had 
upwards of 15,000 employees. He stuck his fingers in the design group 
but he only approved or disapproved of designs he didn't actually make any.

The reason for the magic length of coax was explained in those days as 
give better linearity to the system, which hasn't been replicated lately 
possibly because of other changes in the S-Line exciters and the 30S-1 
over their production runs and updates.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 5/31/2010 4:24 PM, Mike Schatzberg wrote:
> I would say Art Collins did not agree with your assessment when he designed the 30S1. The problem of mismatch is often the result of the use of two or more finals in the amplifier and their resulting parallel input impedance, and the use of a solid state driver with a non tunable final transmitter stage. Collins actually supplied the jumper cables which were different lengths for different combinations of their drivers and the 30S1. You can read about the phase transformation in the 30S1 manual. 73 and Happy DXing, Mike W2AJI
>
>
> -----Original Message-----
> From: Jim Brown K9YC
> Sent: 5/31/2010 8:19:38 PM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] Ten-Tec 411 Centaur Amp Problem
> On Mon, 31 May 2010 15:55:31 -0400, wow_chf at hotmail.com wrote:
>
>> I submitted the article draft to QST, and it was questioned by the Technical
>> Review folks, and although I have been published in QST before, they could
>> not see how this would "transform" the apparent input SWR.
>
> Because it's a POOR fix for the fundamental problem, which is something wrong
> in the input circuit of the power amp causing a mismatch. The proper fix is
> to find and correct the problem in the input circuit. Adding coax is a band-
> aid.
>
> 73,
>
> Jim K9YC
>
>
>