K3 Stereo Diversity on 40 and 80M

There was quite a bit of activity on 40M tonight

Here is an example of a KE5 station who was weak – with diversity on. The UrbanBeam was on Ant1 – the transmitting antenna and fed to the main receiver, and the two KY6R Big Mag Loops are on the second receiver:

And then a stronger station up in Seattle:

I hope you can hear the difference.

80M was in even better shape – less noise than 40M

I noticed that 80M had less noise as we hit sunset. The noise on 40M increased , but it still was S7 instead of what it used to be – S9, making 40M pretty much unusable. It is now usable. So that goal has been reached.

This 80M sound clip is even better as far as showing the “bounce” between the UrbanBeam and the KY6R Loops. His signal is literally fading back and forth rapidly between the Inverted Vee and the loops.

I was very pleased tonight because I now have confirmed that the KY6R Big Mag loops do work better than the Inverted Vee and the UrbanBeam on receive. The loops were inexpensive and MUCH bigger and better than the commercial loops, the two preamps cost the same as about one commercial mag loop, the rotators were reasonable, and the NCC-2 was very expensive. HOWEVER – I can say with out a doubt, and shouting like an old man:

PUT ALL OF YOUR EFFORT INTO YOUR ANTENNAS. THAT AMPLIFIER WON’T HELP YOU HEAR THE WEAK ONES!

Nor will the amplifier eliminate your noise problem . . .

Between goofing around with BCB SWL DXing and playing on even just 160, 80 and 40M, I have already hit my goals and I am very, very pleased. Next I will try out 20M, 30M and eve above – to see how well this new RX system works there.

By the way, here is the Cady chapter on the K3 Diversity implementation:

http://www.pj2t.org/ccc/Elecraft_k3_Cady_ver2o_Diversity.pdf

2 Comments on “K3 Stereo Diversity on 40 and 80M

  1. Awesome!

    The big question I have is just how far I can get with one loop. I get diversity receiving, I was a microwave engineer in the ’80’s. Space diversity is a BIG step up in reliability. How is it implemented in a K3?

    Right now, my amplified loop is much better on 40, 80, 160 and BCB than my inverted V. The difference is better S/N. The thing I would like to gain is more level out of the loop, and going to bigger loop is pretty obvious. I am not too crazy about putting up a pair of loops. I can do one, but two is going to gain me some neighbor and wife flack. Two loops would be a bridge too far here.

    The more I think about it, for my QTH, a multi-turn loop may work. Stealthy but pretty good is the design mantra here. I have been resistant, but adding a NCC gizmo and phasing a loop against the transmitting antenna has a lot of merit. Complicated and a little pricy, but beats giving a realtor a much larger bag of money. Same holds true for diversity receiving if it is well done. Expensive but cheap.

    Antenna season is a way off yet for us in this part of 9 Land. There is a good foot of snow on the ground, and the frost depth is at least 30 inches. Different world up here.

    That is OK, it gives me some time to plan my next steps.

    Thank you for all you have documented!

    Jim
    KF9VV

    Like

    • Hello Jim,

      I did do some testing using the W6LVP Loop phased through the NCC-2 using its RTR-2 TR Switch Feature against the UrbanBeam. It worked better than I expected – and lets you use the loop for either finding the signal or as a noise antenna. I think your idea of using a couple of turns for a loop – to keep it smaller than what I did is a great idea. I know many in EU do this because they have smaller back yards (“gardens”).

      The NCC-2 is pretty ridiculously expensive – but I’m 100% OK with that now – since it has really made a huge difference.

      I also like the ALA100LN preamp by Wellbrook – you might check their site. The size of the loop will dictate which preamp you should purchase. The Wellbrook preamp at the antenna is the best option. Using a preamp in the NCC-2 is second place in my book, and the preamp in the K3 is third place.

      Click to access Elecraft_k3_Cady_ver2o_Diversity.pdf

      For how the K3 does Diversity

      Like

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