[TMC] SBE-2 documentation

[Roy Morgan]

At 12:33 PM 12/15/02 -0500, you wrote:
>Hi,
>Just purchased an SBE-2 sideband exciter on ebay.

Bob,

Did you get the power supply with it?
I cannot locate the Ebay item.. could you send me the item number? Thanks.

>  Does anyone know a source for a manual or schematic for this one ?

You are going to need the whole manual.  The schematic is not enough. This 
is a particularly un-intuitive and complicated piece of gear.  I have a 
digital copy of the SBE-8, 8, 10 manual  (7+ Mb) but do not know the 
differences between that and the SBE-2/3.  I have a paper copy of the SBE-2 
manual and can copy that if you need, but it may be a little while since it 
is holiday time here.

  Send your mailing address - I can at the least make a CD copy of the 
digital manual I have.

I have an SBE-2 here without power supply. I am soon to get a GPT-750 and 
will sooner or later get the SBE running, possibly on Lambda supplies at first.

Some brief notes/ observations:

  - The SBE uses an input power connector that is available from William 
Perry*. It is not practical, and also a sacrilege, to cobble in the power 
needed by ripping out the existing connector.
  - the thing uses diode bridges in balanced mixer circuits - the diodes 
may need replacement or at re-adjustment of the circuit. The diode sets 
look like metal 6H6 tubes but are not.
  - the 8 crystals in the oven UNDER the thing are band setting local 
oscillator crystals. You need them.
  - the 10 crystals in the oven ON TOP of the thing are channel crystals 
for fixed frequency operation. You do not need the ones the previous owner 
used (unless he was a ham).  You DO need  a stable master oscillator 
external to the SBE for variable frequency control.. the Frequency you feed 
to the SBE  ( or generate from one of the 10 crystals) is not  the desired 
output frequency but differs from it by mixer offsets and is also 
determined by the multiplication to be done in the transmitter.. The master 
oscillator operates from 2 to 4 mc for use on all frequencies from 2 to 32 
mc.  The GPT-750 contains a master oscillator.  The TMC PMO is a separate 
master oscillator, as is the Northern Radio Company Model 105 (or is it 
115?), which has very similar characteristics and will do instead (I think).
  - The power supply needed is not particularly complicated but there are, 
besides about three filament supplies, three or four B+ (and maybe bias) 
voltages.
  - the SBE output is on the order of 250 milliwatts.  It will NOT drive 
your grounded grid linear. Do not be fooled by seeing a 6146 as the output 
tube.  This thing puts out about a watt PEP maximum.
  - the relationships between the various sections of the SBE, the controls 
used to manage them, the frequencies involved, and the methods used to get 
it perking along well are such that you cannot be having half a 
conversation with the TV set or the XYL and digest the manual at the same 
time.  My guess is that you will not get it to run with out the manual.
  - the SBE can produce CW, AM, SSB, DSB, Independent Sideband, all with 
varying amounts of carrier level. (FSK, too, I think,, but it may need a 
separate FSK keyer.)


*
William Perry Company
92 Beechwood Rd. (Rear)
Louisville, KY 40207, 502-893-8724
No email or web site that I know of.

You call him or send him a note.
Then you wait a few days and in your mail box will show up the right 
connectors.
Then you send him a check.. Simple.

Roy

- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
roy.morgan@nist.gov --