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@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
|