HF WIRE ANTENNAS
MADE IN GERMANY
30m Operation with the 404-UL
The SWR of the 404-UL on 30m is too high to use without a matchbox. Of course you can match it on that band with most radio's built-in ATUs.
However, if your radio does not have a built-in ATU and you do not wish to carry a big bulky tuner along with you on your portable outing, here is a very simple circuit that will enable you to work 30m, no problem:
Here is the schematic:
Note: the 510 pF is not critical.
A 470 pF capacitor will also work.
I wrapped my coil onto a small
Toroid, but it may also be a simple
air-core coil. Its value should be
close to 0.5 uH.
SWR CURVE (with Mini-Match)
Druckversion 