[TMC] SBE-3 data

[telegrapher at att.net]

I'd really like to find a manual or something in the way of schematic 
etc. for the SBE3.  This is much different than the SBE-2.  Different 
value components, some of the tube numbers, additional voltage regulator 
and other little things.

I'm suspecting that one of the problems is with the diodes in the 
metering circuit.  The unit appears to be working pretty well with the 
exception of the RF output meter reading.  Same with the carrier 
injection value.  Even tho the manual states it's only used as an 
"indicator of something being there" i get virtually nothing on the 
meter when in that position.

However the more i play with this thing the more i'm discovering.

One thing that i need to check out is the fact that i'm using a xtal for 
3870 Kc.  Funny how i found it.  got it all tuned up as best as can 
determine.  Set some levels into and through it with an audio osc. and 
WECO level meter for -20 db input.  Set the audio level for LSB to read 
100 percent like it would be for LSB operation, nothing on USB.  Notice 
that when monitoring the output with my FT-990 that the frequency is 
3889 and not 3870.  Something wrong inside the SBE-3 as it's 20 kc off. 
  Audio doesn't sound to bad but i think if i can find out where the 
missing or added 20 kc is coming from that it will probably work a 
little better.  ALso this unit has an LSB and USB BNC connectors on the 
back panel.  They provide either USB or LSB audio at the 17 KC point 
from the modulation scheme.

I also notice that there is a difference between the USB and LSB output 
levels.  Again i think this is due to something being out of tune in one 
of the different modulator sections.

Comments welcome.  Correspondence welcome also.  SBE-3 literature also 
welcome.  Not SBE-2.  I've got that already but it's very much different 
along with the fact that the SBE-3 provides wideband SSB or AM 
capability, up to 7 kc per sideband, not like the 3.5 kc per channel for 
the SBE-2.

Larry
W0OGH