[Collins] 75S-1 Problem

[Glen Zook]

Basically, the Collins "method" of using a signal
generator at 100 microvolts is the same as using a
signal generator properly terminated for 50 ohms at 50
microvolts.  The resistor was used to provide a "load"
to the older types of signal generators that were not
properly terminated.

A URM25, TS497, as well as any of the older signal
generators like the Measurements Model 80 and Model
82, when used with the external 6 dB "pad" should be
set at 50 microvolts to achieve the same signal
strength as the 100 microvolts plus resistor.  You
will see that the calibration point on the variable
attenuator will be at 100 microvolts for when you do
not use the attenuator and 50 microvolts for when you
do.  There are two lines on the outer portion of the
attenuator, one for with the pad and one for without.

Glen, K9STH


--- "Dr.Gerald Johnson" <geraldj at ispwest.com> wrote:

My 75S-1 manual says nothing about setting S-9 at 100
microvolts. It does demand a 50 ohm resistor in series
with the signal generator. That will reduce the signal
to the receiver.

=====
Glen, K9STH

Web sites

http://home.comcast.net/~k9sth
http://home.comcast.net/~zcomco


		
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