I’m wrestling with several variables at one time – the NCC-2 is an enigma wrapped in a riddle
The NCC-1 and NCC-2 are very interesting units, but quite “counter-intuitive”. Couple this with two antennas of different types and two different ways to feed these signals into the K3, and to top it off – two antennas can be rotated.
“Tuning for a Null” is the strangest thing. Several things need to bet set up right – you need to have the right “level” on each antenna – using the attenuation switches, and also the balance control. You also need to have the antennas pointed in the right direction(s).The best band (by far) to practice this is the AM broadcast band, and during the night hours – where you have several stations on the same frequency. If you have one strong station – or only one station on a frequency, then there really isn’t much to null out – the best way to think or this is that you have several “competing” stations on a frequency, and what you are doing is nulling out other stations and selecting one. The more AM stations on one frequency, the better.
The other part of this is that the K3 will let you do this with either the RF AUX – where you are doing this on the second receiver, or, you can do this using the RX IN – and then you are switching out the Ant 1 Main (TX) antenna. This seems the best way to practice nulling out stations – one antenna in – receive only, and practice phasing the two antennas plugged into the NCC-2. After you get the hang of it – then moving the input to the second receiver – and then you can adjust the level of your Ant 1 TX with the phased antennas.
I have found a station just over the hill in Berkeley at 1400 AM that is perfect to practice finding the null. Then another station at 1480 that I can’t find a null, but where the phase knob selects one station vs. another.
If you go about this with “gain” on your mind – you will be confused at first – its really a complex “soup” of electrically “steering” the direction and where one antenna can be pointed at one station and the other – another, and the NCC-2 then lets you tune in one against the other.
This means its more of a subtractive process rather than the normal “additive” process. In fact, I just turned off the K3 preamp and on 1480, I can tune in one of 3 stations just using the phase knob and attenuation knobs. Of course, with QSB, this can get really tricky – so its almost best to practice with low power stations that are closer and have less QSB.
I have a lot of practicing and playing and testing to do.
The W6LVP and KY6R Loops both do work – and they do have different characteristics. I will play with these two different antennas this week and see if I can make any determination as far as if one is better than the other. It hasn’t helped that the bands have been pretty crappy lately – from 80M up. This means the only band I can effectively test this on is pretty much the AM BCB.
My main goal this week is to see if a larger antenna – the KY6R Loop is better than a smaller W6LVP loop. I do believe that having two of the same kind antenna will be better than what I have now – a large and small antenna with very different “apertures”, patterns and gain figures.
Maybe practicing during the day on the AM BCB will bear some fruit? We shall see.