Hi Matt:
I removed two of the screws on the power transformer on my 575 and put two 3AG fuse holders, one on the side of the transformer and, the second on the front of the transformer. Slightly longer 6-32 screws are necessary. I unsoldered the leads from pins 14 and 16 and put them in series with the new fuses. I also added LED's each in series with a 1K resistor around the fuse block contacts. Now if the fuse blows the LED lights. A rectifier in series with the LED is not necessary as the voltage across the LED is AC.
Reed Dickinson
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On 3/31/2018 9:28 AM, Matthew Hofmann wrote:
Rolynn,
I have removed the side panels and cleaned out some of the dust. In regard
to the possible location of a couple of added fuses, in front of the fan, I
have a couple of selenium rectifier stacks and a thermal cutout, so I am
guessing that my unit is considerably older than yours. So did you connect
these in series with the silicon rectifiers that are in your unit?
I oiled the fan and fired up the unit and it is obvious that my rotary
switches need cleaning. What is recommended for these open stacked
switches?
The trace on the CRT seemed kind of dim, so I may have considerable more
work to do.
Thanks, Matt
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of ROLYNN
PRECHTL K7DFW
Sent: Sunday, March 25, 2018 5:51 PM
To: [email protected]
Subject: Re: [TekScopes] Tektronix Type 575 Transistor Curve Tracer - $75
(Syracuse)
The serial number of the unit I have is 004583, so I am assuming the fuses
are not there (I haven't taken off the bottom cover yet).
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The added fuses are located on top of the main chassis, immediately in front
of the fan motor, hanging off two ceramic strips containing the silicon
rectifiers of the main PS. You will see them by removing the either the fan
assembly or the left side panel.
They cannot be seen from the bottom or the right side as the xformer is in
the way.
Rolynn
Tek Bvtn and Sunset 1966-1971
