Omnidirectional Dual Loop Shortwave Antenna
- Hi all,
I am new in this group.
Is possible have omnidirectional pattern combining two receiving loop antenna ( mounted 90 feg each one like crossed loop ) with passive antenna combiner ( reverse splitter antenna ) ?
With two crossed loops you will also need a 90 degree combiner to achieve an omni-directional pattern. The problem here is, 90 degree combiners don't have a very wide bandwidth.
The other method is to use an SDR that has two antenna inputs and allows for the phase difference to be set at 90 degrees. This will also require a matched pair of loop antennas.
I have supplied ALA1530 loop antennas to some SDR manufactures for this purpose and for DF.
One other method is to build an up-conversion receiver with using 2 Mixers; each one uses the same LO but with a 90 degree phase difference. Both IFs are combined and down converted with another mixer and the same LO and then fed to the receiver. I guess the SDR method is easier!!!
Mount a single loop horizontally approx. 25ft above the ground to provide a near omni-directional pattern.
Lastly, do nothing, because HF signals tend to arrive at medium and high angles, where the loops pattern is omni-directional.
>Almost. You'll need a 90 degree (quadrature) combiner to get the proper phasing for an omnidirectional pattern.
>I am new in this group.
>Is possible have omnidirectional pattern combining two receiving loop antenna ( mounted 90 feg each
>one like crossed loop ) with passive antenna combiner ( reverse splitter antenna ) ?