The Magic of Top Band DX

You just never know when you’ll work the next one on 160M. Mega DX-peditions sometimes do a pretty good job, but you can’t count on working the mega’s like you can on higher bands.

Marcus Island Mermaid

My (next to last) 160M new one was JD1/M – Minami Torishima, an old USCG and Japanese Loran station island.

Surprisingly, Minami Torishima is number 20 in the DXCC Most Wanted. On the West Coast we take it for granted, but the way to work it is to know when a technician is visiting from Japan who is also a ham.

I’ve missed some big announced DX-peditions like VK9MA on 160, but then work these more rare “sleeper” activations that are not widely advertised. I’m at 93 on 160M with Minami Torishima worked on December 14th and then I worked Vadym on St. Marten – PJ7, which is also semi rare on 160M December 31st. You just never know how its going to go. The ADXO list is devoid of 160M opportunities, but someone could fire up tonight and give me #94.

Such is the magic of Top Band . . .

Best 160M RX Solution Yet . . .

Phasing two active loops through the DX Engineering NCC-2 is a great Top Band RX solution for those who live on small lots in the suburbs.

My “previous best” solution was using the DX Engineering DV-40-P 40M phased array as a 160M RX antenna, but in the “both” mode, there was no directivity that I could tell. By having two active loops on rotators and even at different heights – I have something far more flexible, and doing A-B tests, I can “shape” the noise and signal and rotate both antennas to eek more signal out of the noise than I could with the DV-40-P.

On top of that, by using the K3’s Diversity RX mode, I mix in my transmit Inverted L on top of these two phased antennas and it sounds like “multi-aural” stereo. By that I mean signals sound like they are almost “3D”. It feels like I can separate and shift the noise away from the signal.

I had tried this before with two and even three home brewed loops, but they were just OK – they didn’t deliver the goods. They were diamond shape and made of coax. I even tried adding W7IUV preamps, but they didn’t impress me. It seems like the round aluminum loops are better. But now that I can A – B test the MFJ-1886 against the Welbrook ALA1530LNP, I can clearly see that the “magic” of the antenna is the Wellbrook amplifier. It is extremely low noise, and the signal boost is really something amazing.

I’m going to bet the active whips that DXE sells are also an excellent choice for the NCC-2. What is most impressive is how someone on a small lot can have a receiving solution that combats the noise and also delivers signal that is on par with a short beverage.

MFJ-1886, Wellbrook ALA1530LNP and DXE NCC-2

The MFJ-1886 is an “entry level” amplified receiving loop that offers an amazing bang for the buck.

The build quality is simply outstanding. It is even beefier and I think better than the Wellbrook ALA1530LNP in this regard.

The amplifier is very respectable. Its certainly low noise and really makes a big difference. At $200 on an open box never been used sale – this was a big score. FUN.

But the amplifier on the Wellbrook ALA1530LNP is its “secret sauce”. The signal level on the Wellbrook is about twice the MFJ, but I will say, both have a very low noise floor. I am extremely impressed with both loops – and for different reasons:

  • Wellbrook ALA-1530LNP – engineering par excellence in the amplifier (big amplification whilst maintaining a super low noise floor), the loop build quality is just good
  • MFJ-1886 – the loop build quality is outstanding and the amplifier is very good and low noise, just not at the higher amplification levels as the Wellbrook

I’d love to have the MFJ loop with the Wellbrook amp – that would be Nirvana . . .

OK, NOW I Finally have the NCC-2 living up to its hype (and I think pretty darn high price).

With the Wellbrook ALA1530LNP and MFJ-1886 as receive only mode inputs into the NCC-2, serious magic finally happened. I need to mention that having each RX loop on a rotator is a YUGE deal. I can completely switch between the Oakland Airports TSA 10 watt radio station to a high powered ESPN AM station in San Diego on 1.7 mhz. This is even better than a K9AY loop for sure – and is at least as good as a SAL Array, probably better.

One of the things I did was put the MFJ-1886 up higher and above the roof than the Wellbrook – which is next to a creek and not near anything man made for at least 30′. The combinations of XY and Z are mind boggling. This is such a great RX solution for the low bands, I am very surprised that others haven’t crowed about this. It really is a way to get near beverage performance on a small lot – and where you can use a couple simple antennas with rotators to electrically and physically steer the nulls and signal. The NCC-2 gives you the phase angle you need depending on the direction the DX is.

I just checked the EZNec model, and the RDF is just a tiny bit better – from 8.8 dB to 9 dB. I don’t know if this means anything, but the model for a loop up as high as the MFJ is does add 1 dB gain over the Wellbrook that is just above ground by 3′ or so.


Phasing Two Active Loops for 160M RX

One active magnetic loop has an RDF of about 4 dB, which is not that great. On the air however, I find that my Wellbrook ALA1530LNP loop works well when used in the K3’s diversity reception mode. It is a bi directional antenna:

The side nulls are actually quite useful. So, how can we greatly improve on this simple and easy to install antenna?

Phase Two of them with a DX Engineering NCC-2!

The RDF jumps to 8.88 dB RDF, whih is better than a K9AY Loop. You also get a K9AY like pattern, but unlike the K9AY – you can electrically phase the two antennas and electrically “steer” them, and on top of that, you can mechanically steer them using the two rotators that these loops are on.

Think about it. If you live in the suburbs with neighbors that have noisy gear – or you have noisy gear in your house, you want to try to notch the noise out by steering the nulls toward the noise source. This phased active loop arrangement should work really well, and later today I will know for sure.

KY6R Upgraded RX Antennas

Tomorrow at this time I will be listening to two phased active loops – one the superb Wellbrook ALA1530LNP, the the second, something I just have to try – the MFJ-1886. The MFJ just happens to be an open box special at HRO Oakland. Because its $50 off and has a full warranty, and because I won’t have to pay the additional drop shipping charge from MFJ, this was too good an offer to pass up.

I will report back on how the MFJ compares with the Wellbrook. If it is even “close” it will be a big success and worth the low risk and low cost gamble.

Right now I use the Wellbrook and the Inverted L in the Elecraft K3’s “dual diversity” mode. I expect that phased two loops on top of that will be even better, and the fact that each loop has a preamp at the antenna and that each has a rotator, there are many ways to eliminate noise and enhance signal.

I’ve done testing in the past with passive loops and also a passive “double K6SE Loop” and they worked well through the NCC-2 – but this should be quite a bit better based on my Wellbrook experience. The Wellbrook is heads and shoulders above a passive home brewed RX loop.

3G9A: Propagation Checks

I’ve done enough testing for 3Y0Z, and realize that the best test will be to track them as they travel and when they are /MM

This will be fun and exciting as we wait for this epic DXpedition.

Ham Radio Propagation Studies

I’ve been waiting two years to work an ATNO, so it should be no surprise about how excited I am to work 3Y0Z. Rather than just “anxiously await”, I decided to collect some data and see if I can identify any interesting propagation behavior(s). The 20M openings at the West Coast sunset vs. sunrise and during “Cross Quarter Days” is something I have never looked at carefully. This now has me realizing what ham radio operators can do to advance the science of propagation.

While on vacation in Montana this past September, I read a fantastic book about Richard Carrington and the birth of modern day solar and propagation studies. The biggest take away is that while we know a lot about the solar cycle, there is probably a lot more that we don’t know. Reading the Sun Kings, I realized how important data is, and how some insights can be overlooked for years, such as what was going on during the Carrington Event. I also know that we know very little about 160M propagation, and so ham radio operators collecting data can actually do some great work in this area.

Another orthogonal connection that I made is reading the Samuel FB Morse biography reminded me that the Carrington Event happened in the early days of commercial telegraphy, and that it affected the telegraph lines and stations and even operators. What was interesting is what the solar astronomers knew and when. There was a big delay between when the Carrington Event happened, what solar astronomers saw and knew, and then later how several “mysteries” were solved. What was also interesting was how several astronomers quietly working away in their own world later shared their data which then validated their theories.

I think this is just one of many ways ham radio is a wonderful hobby and so much more. Even today with all of the technology and data available, we still have big opportunities for new discoveries.

How many hobbies can offer this?