Revised versions of VLF/LF/HF Vertical and HF Active Vee antennas


Chris Moulding
 

Recently I was asked by a customer if it was possible to reduce the DC current consumption of the VLF/LF/HF Active Vertical antenna as he wanted to use a solar panel and small battery to power it and a receiver at a remote location.

The original amplifier design used a JFET amplifier followed by a bipolar transistor output stage to match to 50 ohm coax cable. This used over 100 mA so it would take a high drain from a solar power battery system especially overnight..

I've redesigned the amplifier to use a transformer after the JFET amplifier to match directly into 50 ohm coax and to reduce losses in the base unit replaced the Owen splitter with a hybrid transformer. Other minor resistor value changes to reduce current drain from the green Power LED were also made.

As a result the DC current consumption is now down to 15 mA and the RF output and IP3 performance is identical to the original version.

All new VLF/LF/HF Active Vertical and HF Active Vee antennas will now use the revised amplifier. Amplifier and base unit PCBs will be marked with the number 2.

Regards,

Chris

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