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File : /G6LBQ Bitx/Multiband HF Linear Amp/HF Amp Rev3.png
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Description : Prototype Multiband HF Linear.

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Regards,

g6lbq <ah.electronics@...>

Hi everyone.

I have posted an image from my PCB CAD program of what I hope will be the final revision of the Multiband HF Linear Amplifier.

The amp has given me a few headaches and I have moved the goal post from my original design criteria more time than I care to mention!

The amp will produce a stable and linear 10watts of RF power and I have included on the PCB a PI network attenuator so the board can be matched to other projects or configured for lower power should it be required.

With sufficient drive the amp is capable of producing 20watts of RF power.

The amp has built in electronic switching for the bias circuits so a big plus for portable battery operation.

The PCB is single sided so reproducible for those wishing to make there own board.

The PCB has all the connections needed for hooking up to the BitX/Multiband and Low Pass filter module. The input on the Amp is switched via a douple pole changeover relay so the amp is fully isolated from the BitX transceiver during receive to stop feedback/instability which has been experienced by BitX users.

The RF output devices are mounted along the PCB back edge which allows greater flexibility when choosing a heatsink, the amp can even be mounted such that the output devices mount directly to the back of an aluminum case which is sufficient for dissipation when using the amp at 10 watts output.

More to follow soon but hopefully the amp will prove a great addition for the Multiband BitX as well as other and future projects.

Regards

Andy de G6LBQ