[Milsurplus] MO-1 / MAK Operating Precautions

[Hue Miller]

Service Notes Navships 900,000.1 

Operating Precautions for the MO-1 / MAK Equipments

Due to the high modulation capabilities of the
MO-1 / MAK equipments, it is essential to assure
that the final amplifier is loaded at all times when
modulation is applied. Otherwise dangerously high
voltages can be generated which may damage the
insulation or the connector plugs. To eliminate the
possibility of such damage to the equipments, the
following precautions should be strictly observed:

1) Preliminary tuning should be accomplished with
an unmodulated carrier.
2) Completely resonate the antenna circuit and 
adjust coupling so as to load the final amplifier
to 95 to 100 mA plate current.
3) Do not apply modulation under any circumstances
unless there is a load of at least 95 mA on the 
final amplifier.
4) With the final amplifier loaded from 95 mA to
100 mA, 100 percent modulation is easily 
obtainable. If the plate current is allowed to 
drop below 95 mA, the transmitter can easily
be overmodulated. If the plate current is more
than 100 mA, the plate dissipation of the tube
will be exceed; also the percentage of
modulaton will be low. Therefore, care should
be taken to maintain proper loading on the final
at all times.
5) When using ICW, it is recommended that 
the feed-back resistor R-122 be adjusted so 
that the percentage of modulation be adjusted
so that the percentage of modulation does not
exceed 80 percent with the power amplifier 
loaded to 95 mA.
6) Never attempt to shift frequency with the 
key down, using ICW. Under these 
circumstances, the final amplifier is 
momentarily unloaded and the insulation 
can be damaged. 
Since there have been several failures of 
connector plugs in these equipments 
which are directly attributable to improper
operation, strictest compliance with the
above precautions is recommended. In
this connection, it is suggested that a 
notice be posted near the equipment,
reading as follows: 
WARNING
With The Final Amplifier Loaded To Less
Than 95 MA Plate Current

[ sic! that last line is verbatim, but seems
incomplete! Also, at the end of paragraph
5, there is an odd partial line:

" as 9, the separation between turns in L-112
and L-114"

That's all there was! I wonder if this line belonged
to this equipment or fell in from some other 
equipment's page???

via: Hue Miller   re: couple of members running
this equipment!