Has anyone used a Loop On Ground antenna for diversity reception?

KD0RC

I have a Flex 6400 and am experimenting with a Loop On Ground (LOG) antenna. So far, so good, especially on 40 and 80 meters. When there is bad atmospheric noise, it often works better than my end-fed, G5RV or 80 meter half-sloper. The only time it beats the beam is if a station is off the side.

The question is, has anyone used the LOG in diversity reception? Does it compare favorably to other antennas used as the diversity antenna?

Does diversity help compared to just switching back and forth between the loop and transmit antenna as I am doing now with my 6400?

I am considering building a much bigger one to do better on 160, but that may have to wait for spring…

Thanks to Dan, KE0SYB for pointing me towards this interesting (and easy to deploy) antenna.

Mike-VA3MW

Hi Len

I have 2 BOGs and sometimes I have used a DX Engineering active loop. I have used all 3 for diversity at times.

And, yes, it is a game changer in a contest. One night during CQWW SSB, 80M was terrible and I was going to give up. I had forgotten about diversity and set RX A do the Active Antenna and the other ear on the full sized antenna. I made 200 more Q's. It was fun to listen to which ear heard better and it was an education. I use it all the time now.

I am sure others will have a comment. If you get a x600 series, you will need to give it a try.

Mike

Neil D Friedman N3DF

Not clear if you understand that 6400 is not capable of diversity reception—can only monitor one antenna at a time.

KD0RC

Hi Neil, yep, I sure do. I am asking because I can't do diversity reception to test it out.

Neil D Friedman N3DF

I should have known.

KD0RC

Thanks Mike. I operated in the Medium Speed Test (MST) on 40 CW last night. I had to keep switching back and forth between my main antenna and the LOG. A dual-SCU rig would have helped a lot.

Mike-VA3MW

I did this video some time ago, but play it with headphones on.

See if you can hear the effect.

https://youtu.be/BDZqIASwCNU?si=bMBTr0ZkHMzFcoa6

Bill AB7AA

Over the last two decades I've done diversity with a number of antennas, but I don't have a LOG to give you a direct comparison. In my experience any two antennas with different characteristics will work well as long as both have reasonable S/N ratios. Different polarizations at nearly the same feed location works well. However, two horizontally polarized antennas have given great reception if their feed points are at least 2 wavelengths apart. Just make sure that they both have about the same S/N ratio in the same direction. eg. BOG and yagi pointed the same direction. Using a poor antenna just to have something different can introduce a lot of noise in one ear.

Bill AB7AA

KD0RC

Thanks Bill. I have listened to some 6600s and K4s in diversity and they were all verticals and dipoles. They all worked pretty well, but the verts sometimes picked up enormous amounts of noise on the lower bands, especially in the summer.

My LOG is really quiet and the S/N is often as good or better than my end-fed on 80 - 30. 160 is not as good.

I need to encourage my buddy with a 6600 to add a LOG to his antenna farm so that I can better evaluate it.

Bill AB7AA

Len,

What gives a great visual of diversity is to transmit from two transmitters on different antennas with about 100 Hz spacing. Receive with a remote SDR. I use SDR's at a distance that correlates to minimum takeoff angle (VOACAP). On the remote panadapter you'll see the two sigs QSB quite differently. It's a real eye opener to see both sigs sometimes 15-20 db different from each other, and then reverse, all the while knowing both are coming from the same lot!

This now is the only way we test antennas. I use my LPDA as a reference antenna and then any other as the test antenna. You have to average the sigs over a 60-120 sec test to calculate the difference. It's nice having an XYL with a license so that we have different call signs on each transmitter just to be within the letter of the law.

73,

Bill AB7AA