A general-purpose 1:1 Current Balun for use on HF with your 100w transceiver. This revised design uses larger/stronger screw-eyes for strain-relief on Dipoles and top-mounted terminals catering for balanced-feeder on a Doublet or G5RV. You could also position it at the base of a resonant vertical - to act as a choke/isolator. An effective Balun should be resistive across the frequency range being used - and our choice of FT140-43 toroid is suited from 5MHz up to 30MHz.
May also be used in place of the internal Balun found in cheap ATUs which are usually 4:1 Voltage Baluns and not always ideal. In this instance, coax to the ATU should be as short as possible.
Weather-proof - inside is filled with potting compound. All fixings are stainless-steel.
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!
Running more power and/or want better performance on 160/80/60m? We also offer a 400-watt version...
Choosing a Balun
We are often asked "what balun should I use?" by customers - here's our simple guide to choosing the right one:
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!
We do not advise the use of "ugly chokes" (air-cored coils of coax) for use at HF - these do not offer a consistent choking impedance and, in some cases, can actually increase common-mode current! Simply put - Use a 43 or 31 mix ferrite toroid and a coax of a suitable power rating. At VHF, a few turns of coax is perfectly adequate - for 50MHz/70MHz, Aerial Parts of Colchester offer a ready-made choke for a yagi.