[TMC] Board numbers

[telegrapher@att.net]

I've got several different STE exciters here that i'm working on.  One
of them pretty well matches the manual i have but the other one has what
i would consider newer version boards.

My board numbers are as follows:

Older STE-1 SN 24396

Audio board - A3221-B
IF board    - A3222
CW Osc board- A3278
Power supply- A3153:  This board has a working -36V, -12V and +12V
supply although it reads low.  New filter caps probably required.

Newer STE-A1A/U - SN 33001

Audio board - A3221-G
IF board    - A10603-5-B
CW Osc board- A3278
Power Supply- A3153-C:  On this board the -37V regulator transistor is
strapped out because of a defective 2N350 regulator transistor.  This
throws a much higher voltage on the RF deck part of the TTRT module. 
Where do you find replacements for them?

The TTRT modules i have are:

TTRT-2D with board A10635-B, with a separate detached RF osc assembly
attached to the main RF board with 5 wires.  Pins 1&2 are supply voltage
for the oven heater on the RF osc. assembly.  Then + or - voltage on pin
3, apparently 37V, ground on pin 4 and pin 5 is the RF output into the
buffer and then mixer etc. circuits.  On both of the STE units, pin 1 &
2 are 115V for the xtal ovens.  However, not all the TTRT units are 115V
units.  They have them for 12, 24 and 32V.  What's this one?  Who knows.

TTRT-2/F with board A10635-5 is similar but with different off board
components.  Again the 115V ac for the oven assembly leaves the board on
pins 1 & 2, then goes into a small transformer, then hits a diode bridge
then to a 50uf filter then to the Osc. oven assembly.  This unit also
has a potentiometer in the circuit, for what reason i have no clue. 
going from the Osc/oven assembly back to the main board are only 2 wires
now.  One for RF to the buffer etc. circuits and the other for source
voltage for the xtal osc assembly.  I think they are using the chassis
connections for ground return in this case?

TTRT-1 has a mfg. date of 30176 and the board number is A3362.  This one
matches the manual so i've pretty well figured it out.

Appears that not all TTRT modules are useable in all models of the STE.

What i'd like is to find out what the other owners of these units have
for boards and manuals.  About all the transistors are way out of date. 
I've located a variety of them and may pick up several of each just so
i'll have spares.

If you've got an STE with or without TTRT units, i'd certainly like to
hear from you to compare notes as to what all is around in inventory.  

I've found a variety of problems in them from dead electrolytics in one
item to no signal thru the CW osc board (required) to RF all the way
thru the unit till it gets to the final output transistor a 2n3553.  

There is virtually nothing to address how much voltage should be where
in the circuits or between boards.  As there is no standardization as to
design of the different modules, i'm thinking that if we pool efforts
and resources, we can have working units.  I know there were 2 other STE
units sold on ebay either last year or earlier this year.  Would like to
hear from you folks if you've got time.

Also where can you find reasonably priced xtals in HC-50 holders?  These
are smaller than HC-6 units.  

Hope to hear from you prospective STE operators.

Larry
W0OGH