Amateur Radio Technical Notebook – GM3SEK

Best of ‘In Practice’ on the web – Articles and resources of long-term interest, including switch-mode power supplies. GM3SEK’s Amateur Radio Technical Notebook which also contains the archives of old Radcom ‘In Practice’ column.

The DG8 – a Low-Cost, High-Performance Masthead Preamp for 2m – by Ian White GM3SEK

A masthead preamplifier is the greatest single improvement you can make to your receiving performance for VHF/UHF DX and contesting. But the preamp MUST be at the masthead for optimum performance, and unfortunately many preamp designs leave the user to provide the necessary RF switching and weatherproofing. ….

The DG8 Masthead Preamp for 2m is designed specifically for outdoor use, close to the antenna.The integrated single-board design avoids the expense of coaxial relays without any significant impact on performance …

Amateur Radio Technical Notebook – GM3SEK

The Triode Board – PC board and Kit for Triode PA control and protection – The Tetrode Boards – PC boards and Kit for Tetrode PA control and protection.

Cost-effective Ferrite Chokes and Baluns

“But remember that an HF ferrite choke will typically need 6-8 turns passing through the centre hole. Regardless of the type of core, one pass through the centre will never be effective at HF!”  – GM3SEK