During the construction & testing of the various modules it became neccesary to produce several items of test equipment to enable testing to be carried out over a period of time simulating actual use and also to comply with the terms of my Amateur Radio licence.
The amplifier was tested using a power attenuator rather than a dummy load ( an Artificial Aerial ) so that the amplifier's performance could be checked without causing health & safety issues . After all , 200 Watts is rather a lot of power to put in to an aerial in a lab !
The continuous use was simulated by using a pre-programmed PIC microprocessor to operate the transmitter giving the callsign & location of the testing so that if there was any problem with leakage of RF signals ,I'd followed the licencing regulations !
Circuit of the PIC based keyer
Picture of the assembled keyer
Due to the non availability of a suitably rated commercial power attenuator for the amplifier at the start of the project , it was necessary to construct a unit for this project, using a commercially available attenuator element then design & fabricate a suitable housing for it. The design criteria were not too critical as the unit's performance could measured using available test gear .
Pictures of the completed Power Attenuator
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Back To Table Top 200 Watt 145MHz Amplifier
This page last updated 23rd Oct 2009