This is a no compromise solution. A robust 1:1 Choke Balun for use with a Doublet or G5RV where ladder-line meets coax - Perhaps just after your ATU. You could also position it at the base of a resonant vertical - to act as a choke/isolator. We don't cut corners: This balun is wound using RG142 coax and the ferrite core is an FT240-31 offering resistive performance between 3.5MHz and 30MHz so a perfect solution for your all-band HF aerial - and it's rated for over 400 watts continuous.
160m/80m : If you intend to use this Choke mostly below 15MHz, we can supply it with 12 turns instead of the usual 8. This gives improved choking performance on the lower bands but it can still be used across the whole of HF. Please note that this is a custom option and will add 24 hours to the delivery time.
Check out the 2nd picture showing the inside - clear casting-resin for a weather-proof seal!
Made (and used) by us - Be weary of any supplier who can't (or won't) tell you what's inside the box you buy!
Baluns - What/Why?
It's good practice to put a Bal(anced)Un(balanced) where coax meets aerial or balanced-feeder. A Balun will help prevent "common-mode current" on the outer of the coaxial braid - This is vital to ensure that RF does not flow down the coax, turn it into part of the antenna system and give you "RF in the Shack". Using a 1:1 Current Balun at the junction of balanced-feeder+coax is preferable, in most cases, to a 4:1 Balun - and certainly better than the internal 4:1 (voltage) balun found in many tuners!
Choosing a Balun
We are often asked "what balun should I use?" by customers - here's our simple guide to choosing the right one: