Asymod IIIs Installation Manual page 13

+15volts, +24 volts supplies which are located under the DC/DC converter and at the bottom/copper
side of the board. Please refer to the DC/DC converter section on page 32 for details.
The Asymod III may be set up in any one of the three following onboard configurations:
A- Single MJE3055T transistor (T2) with a maximum collector current of 10 Amps. (Standard)
B- Dual MJE3055T transistor (T1 & T2) with a maximum collector current of 20 Amps. (Request)
C- Single TIP35C transistor (T3) with a maximum collector current of 25 Amps. (Request)
Although configuration A will work fine with most 4 watt transceivers, for heavy use, configurations B or
C are recommended which withstand higher duty cycles at lower temperatures and are available upon
request.
Although the Asymod III will perform well with the modulating stage transistor/s onboard mounted on
an adequate heatsink or the transceiver's chassis which can provide proper cooling, the final modulating
stage transistor/s may be mounted outside of the board and on the heatsink of the transceiver or other
enclosure with the appropriate cooling using wire extensions.
Configuration A
When using configuration A, make sure to secure the board and T2 well with the mounting hardware
provided. You may install T2 outside the board on the transceiver's heatsink or chassis using wire
extensions.
Configuration B
When using configuration B, make sure to secure the board and both T1 and T2 well with the mounting
hardware provided. You may install T1 and T2 outside the board on the transceiver's heatsink or chassis
using wire extensions. Alternatively, you may install T1 and T2 in parallel with more transistors of the
same part number combined with .1 Ω / 5W resistors as seen on FIG. 5C.
Configuration C
When using configuration C, make sure to secure the board and T3 well with the mounting hardware
provided. You may install T3 outside the board on the transceiver's heatsink or chassis using wire
extensions. Alternatively, you may install T3 in parallel with more transistors of the same part number
combined with .1 Ω / 10W resistors as seen on FIG. 5D. The TIP35C has a maximum collector current
rating of 25 Amps, and is sure to withstand higher duty cycles at lower temperatures.
Make sure that the modulating stage transistor/s are securely mounted with the appropriate mounting
hardware provided; thermal silicone rubber & fiberglass composite insulator pad, bushing, and screw.
Make sure the modulating stage transistor/s are mounted to a large enough heatsink or part of the
transceiver's chassis to sufficiently dissipate the heat. It is recommended to place the transceiver in
ventilated area. The use of a cooling fan is recommended for heavy use. Make sure the board has all the
support screws installed with the necessary hardware including any brackets, stands-offs, spacers, and
that the board mounting screw hole pads have good contact with the enclosure chassis. If the
modulating stage transistor/s are mounted externally, check for shorts and make sure all the wire
connections are firm and ran correctly before powering up.
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