[GreenKeys] More TU-170 questions

[Ralph Mowery]

John take a closer look at the schematic.  The .125 fuse is only in the DC
loop supply side that is normally set for 60 ma max or 20 ma.  It seems to
be one of the fuses that resembles a resistor and is wired in the circuit
board.


There is a much larger fuse that is in the AC line.  Looks like one of the
3AG type that is more common to most people.  It is not shown on the
component schematic, but on the chassis wiring .  I did not see a rating for
that one, but it should be high enough for the tu170 and the teletype motor
circuits.

Ralph ku4pt



-----Original Message-----
From: greenkeys-bounces at mailman.qth.net
[mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of w9ddd at tapr.org
Sent: Sunday, December 27, 2020 2:30 PM
To: greenkeys at mailman.qth.net
Subject: [GreenKeys] More TU-170 questions

The SSR questions got me to looking in the manual again.
No specs on the motor control SSR.
They list the fuse as 1/8 amp.  Tracing the circuit diagram shows that the
switched outlet is fed through that fuse.  I don't think that would work.
Either the  drawing is in error or the fuse size must be wrong.

When I return home I'm going to have to take the cover off to replace the
meter lamp so I may as well investigate then unless some already has the
answers. 

John, W9DDD