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160m coils


Building a Hans Loo Tri band 80 40 20M antenna linked with a 80m coil inverted V DP.

Seems i have been quite good doing the 80m coil just made give a freq of 3.700mhz happy with that on me as my analyzer is telling me

Now for the question as the Loos antenna coil is a 40MM WASTE PIPE WITH 55 TURNS OF 0.75MM OF INSULATED WIRE (awg21) To make a 160m coil does one simply make a coil with 110 turns of same wire and former and then add a turn or take one off till i get roughly what freq am after around 1.930mhz. So when want to do 160m take out the 80 coils and replace with the 160 coils

Very new to doing loading coils.

thanks again for info

As when it is doe will take it up Kitt hill and do me yearly visit to place LOL



Hi Karl,

Finding a bigger coil for resonance at 160m by trial-and-error should work.

The inductance of a solenoid coil is proportional to the square of the number of turns. Therefore I would start from something like 80 turns. It might even be possible to calculate the required inductance. Let’s see what some wiser men will answer.

73 Heinz, OE5EEP


Hi Karl
Maybe you know another calculator, I’m using this
73 Eric F5JKK


Interesting. Give good indication on length of wire you need in this case .75mm as need about just over 15.5m of wire.

But how do you know its freq its going to work at. is there another cal you can use to find that

thanks again all learning curve and useful information



Hi Karl,

When you have arrived at the correct number of turns for Top Band,
could you not put a removable tap in at 55 turns so you could just
disconnect the link for top band, and reconnect it for the other bands.
It would save you having to change the coil

Best 73 Dave


and less to carry its possible cheers for idea