Rev 1.03
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a temperature of 61C which was a rise of 33C above the ambient temperature of the lab. The
transmission was switched off after 40 minutes (see chart).
In summary: Enclosing the PA kit in an enclosure will increase the temperature rise; using fan-
assisted cooling would reduce it. There are many factors that will influence heat dissipation. The
above discussion should be taken as a guideline only
– your mileage may (WILL) vary!
5. Power Amplifier characteristics
Please refer to section 5 of the full PA kit assembly instructions. The measurements there were
made with the full assembled kit. This simplified kit assembly does not suffer voltage drop across
the power modulator, nor does it have any attenuation in the leakage gate. Due to this, the output
power will be slightly higher with this simplified kit assembly.
6. References
•
App Note AN004 explains how to use this PA kit in conjunction with an Ultimate3S
QRSS/WSPR kit to increase the output power to around 5W, and apply raised cosine RF
envelope shaping for a beautiful clean click-free signal. Refer to
•
For updates relating to this kit please visit the QRP Labs PA Kit page
•
For any questions regarding the assembly and operation of this kit please join the QRP
