[TMC] SBE-2/TIS-3

[Telegrapher@worldnet.att.net]

Several of what i would call abnormalaties existed within my SBE-2. 
First i noticed that when switching the meter between the various
positions that the meter would bang against the right side of the
enclosure.  New tube appears to have fixed that problem.  

When i first got the unit i had plenty of MF carrier insertion.  Went
thru and checked all the tubes first of all and replaced one that were
below minimum standards per the Tube tester listings.  Hmmmmmm.  Now i
have to turn the MF drive almost all the way Clockwise to get to the -0-
db point on the scale.  Wel i'll work on that one some more.

This led to the next discovery.  I have an original SBE-2 manual and in
the schematic it refers to V-101, V-102 and V-103 as 6C4 type tubes. 
However, the chassis is stamped as 6AB4.  Was this a change that the
paperwork has not followed the manual on or did something go wrong in
the factory?  Tag on the unit says SBE-2, not -2a etc.  

Also i notice that with the MF carrier insert control completely CCW
that i am still transmitting some carrier.  Possibly a good tuneup will
clear this minor problem as it was probably affected by new tubes and
aging components.

I relieved a friend of mine with a pile of transformers of one that had
a 200-0-200 winding and 6.3V @ ?amps.  Another 6.3v @ 6 or so amp fil
xfmr on the same chassis and run from a Variac brings the B+ voltage to
175-0-175 which is what the original put out.  Tied the filament xfmrs
and 200v winding into the post transformer wiring and the unit appears
to be working quite happily and very stable indicatiing 0dbm output on
the meter easily, however the actual output on the back terminal strip
is a -1.1 dbm.  Additional work is evident here as well although my
other equipment manuals indicate that a -20 db level will drive them
fully.  

It appears that some sort of monitor scope on the output of the Amp or
transmitter is indeed necessary in order to make this stuff sound
proper.  

Any help on the difference in the tubes in the SBE-2?

Thanks

Larry
W0OGH