This is a updated collection of easy to build projects for radio amateurs and swl's. See all my projects in the OLDER POSTS down this blog.
Have fun.
73' John

Mutual respect is the key to global peace.....

Thursday, November 21, 2013

Traveltuner 3.5-30 MHz

There is no known qrp tuner for both small magnetic loops and longwire antennas for sale so here is an idea for your next holiday .  A 2.5 m circumflex loop wil cover 6.5 - 30 MHz  ,  a 5m loop wil cover  3.4 - 8 MHz. To tune a loop tune C1 for resonance and C2 for low swr . To tune a longwire switch to the coil for the desired band and tune C1B for best swr. The coil can be replaced by a T130-2 toroid with 50 turns 0.8mm enamelled wire on a 12 positions rotary switch. Use a plastic cabinet for this tuner.
Tuning capacitors :
Disclaimer:I'm not responsable for any damage due to improper reproduction of my projects.