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.....

Tuesday, February 04, 2014

Mini Travelloop for receivers

Portable shortwave receivers are normally equiped with short telescopic whip antennas producing  a poor  reception. This option has more selectivity and a better impedance (low Z) over the 6.8-31 MHz range.
The design uses a single 15-520 pF type tuning capacitor combined with a FT37-43 toroid having 7 turns  on the coax side. A FT37-61( 4c65) with 3 turns can also be used. The loop is made of 3mm brass wire 1m long. Use only plastic enclosures.  Tuning range is 6.8 - 31 MHz with oustanding performance. This is also a verry good direction finding antenna. A RG-213 loop gives a higher Q with much stronger signals.

The coupling by a FT37-43 with 7 turns

The small loop in action on 80m. by switching a 1500pF capacitor over the tuning capacitor

Disclaimer:I'm not responsable for any damage due to improper reproduction of my projects.