DXA and 5K0T

5K0T is on the air and running with DXA – so if you’d like to get in their log or just follow along, here is the URL:

http://www.dxa3.org/5k0t/

160M: The Inverted “Fishing Hook”

My antenna now looks like some weird Inverted J or Inverted Fishing Hook (?). Its similar to the “AKI Special” antenna documented on page 9-72 of the ON4UN Lowband DXing Book. It is now 60′ tall at its apex, and then the wire trailing down skirts the very large Blue Spruce that its top wire is pulled up to. A year ago, the Diablo DXers helped me launch a rope in that very tall tree, and this time I used plastic covered guy  wire so the squirrels won’t eat it.

The vertical section of the Hook is a 41 foot Spiderbeam aluminum pushup mast – very heavy duty and mechanically and electrically bonded.

I’m pretty sure it actually has less of a horizontal component and is between an Inverted L and a vertical – which is a very good thing. It still has some, so it has a nice range of take off angles – where too low a take off angles would be bad for me down in my bowl QTH.

Its 121′ total, and is resonant just above the 160M band, which is no problem with the AT2K tuner.

You can see how the tuner will get stressed on 80M, but the other bands where the tuner will have a very easy time would be 60M, 30, 20, 17, 15, 12 and 10M.

Top Band Common Mode Quick Fix

I was able to move the top hat wire on the Inverted L so that it now heads East instead of North, which on 160M offers these benefits:

  • The direction will be better for working the last 10 that I need. It is a good path to the Caribbean and most of Africa, which are my “night time” Top Band direction. Using RBN, I’m very surprised how much difference it makes
  • The antenna is now father away from the house and where the 20M yagi will be moved to. It also is no longer in the near field of the 40M array – so all around the placement of all three antennas that I have are optimized for my small lot
  • I got rid of the tuner at the base of the antenna and am just going with the AT2K in the shack. The presentation I posted the link for yesterday has me convinced that the convenience of the tuner being shack based outweighs the (smaller than I expected) benefit of it being at the base

The only thing that it didn’t do is get rid of me turning on the HVAC blower when I transmit on 160M. Even at 100 watts! However, futzing in the back jarred my memory, and its no coincidence. This past spring – when we had annual HVAC maintenance, the tech replaced a condenser in the AC unit. Ever since he did that – I have had this problem. I am sure the condenser is acting like an antenna.

I solved the problem. I just turn the damn thing off! I will also attempt to add snap on chokes, but its kind of moot – because when the heater comes on – it trashes my radio on all bands. So – I will heat the house up for Kat and turn the damn thing off when I’m in a 160M pileup. Problem solved!

I have several things in the house that cause RFI, and have those all under control – so its a good feeling to know that I can at least get back on 160 and not have the AC bug my wife while she is sleeping!

Final KY6R 2017 Top Band DXCC Sprint!

Wow we only have 6 weeks left to 2017.

I didn’t get my 160M QSO with VK9MA, so lets move on and see what is next:

  1. J5T – Guinea Bissau – remarkably, I heard this superb team on Top Band, but won’t call them until later today – they were very busy with EU and the US East Coast. I do expect that when they get to the same point as they did with their recent 3X DXpedition, that I will work them. How do they always rock on Top Band? Bravo!
  2. YJ0JA – Vanuatu – close to VK9MA – this will be interesting
  3. TO2SP – St. Barts – very possible
  4. 9G5W – Ghana – possible
  5. CQ WW CW – there are about 6 that I need that should be on 160M – I should pick up a few
  6. XW4ZW – Laos in December – not holding my breath, but Ken has an excellent update on the Solar Cycle – https://www.qrz.com/db/xw4zw

Carl, K9LA says solar minimum – 2019. We will most likely have a long minimum before Cycle 25 – more than 2 years – probably as bad or worse than the last one – and then that cycle will be as bad or worse than Cycle 24. LOW BANDS, LOW BANDS, LOW BANDS

Top Band will be very good. This will be the saving grace DX wise – 160 will become more crowded and with low absorption we should se exceptional conditions on 2021 – 2022. 80M will also be very good. 40M could become a 24 hour DX bands – especially near the Winter Solstice. Transpolar propagation will become very weak. HOWEVER, LP on 40M to Glorioso for me at sunrise will be the trick. 20M will be dead for much of the bottom.

My predictions for 2017 – I will end up with 95 on Top Band this year. That’s less than the 60% norm for me as far as a success rate goes. Its still very possible to make DXCC on 160M and 9BDXCC by the time KH1 hits the air.

OK – now onto fixing that RFI issue …

 

 

UPDATE on FT8 . . .

While I still think FT8 is the most exciting new digital mode, the oldest digital mode, CW is still the King for DXpeditions.

Here is the Update I have added to some of my more “exuberant” FT8 posts:

“UPDATE: After the VK9MA DXpedition I have changed my tune. FT8 surely is the beginning of something very exciting, but when VK9MA kept switching between FT8 and CW I realized just how much better CW is. On paper, using a mode that could work when CW was too hard to “hear” seemed like magic, but because there still was enough back and forth with FT8, what you gain in being able to decode a weak signal – you lose is the back and forth with QSB. FT8 would be better if it could send CW and just do the 599 TU thing.”

I do think FT8 will be especially excellent for the upcoming ARRL International Grid Square 2018 operating activity. I also think that operating activity will help the developers of FT8 move it closer to a fast mode that could be all that I see as a great future for DXpeditions.

Make no mistake – FT8 is the beginning of something really great – but it is just the beginning.

 

The RFI “Sleuth”

In the last year I made two changes to my antenna farm that introduced RFI issues. Not RFI in the shack, but RFI that I am causing that:

  1. Only on 160M I all of a sudden cause my Trane Heater blower to turn on and off for short periods – just enough to blow cold air through the house and make fan noise
  2. Turn my garage opener on and open the garage door opener when on 20M

Must be Common Mode RFI – because I clearly remember Jim, K9YC discussing this:

http://audiosystemsgroup.com/NCDXACoaxChokesPPT.pdf

At first I thought it was the antennas – that they were too close to the house, but that doesn’t wash because I have had similar antennas on these bands before (in the same locations) – and was running 1500 watts with my ACOM 1500.

There is one thing I have done that must be causing this – I used to have a Palstar AT2K tuner in the shack and I never had these problems. This leads me to believe that my problem is caused by my coax radiating RF because there is no choking in the shack. There is choking on the antennas, which I thought would have prevented this, and I don’t have this issue on my DX Engineering DV-40-P 40M phased array. But that antenna is the farthest from the house.

SO, the best question to ask so you can try to inform a hypothesis:

“What has changed that could be causing this?”

The only thing has been to move the tuner from the shack out to the base of the antenna, and I sold my ACOM 1500 and replaced it with the SPE Expert 1.3K FA.

I have used my home brewed Field Strength meter in the shack looking to see if maybe the SPE amp isn’t as well shielded as the ACOM was, but when I use my KX-Line running 50 watts in JT8, I still turn on the Heater on 160M. The “drop off” away from the amp and any radiation is literally an inch or so – so its not a “leaky” amplifier.

I will set the KX line on during the day and walk along the feedline and see where its radiating. I am guessing that the near field of the coax – near the point of entry where the coax leaves the house and goes to my remote Array Solutions Rat Pack switch does go right next to the wiring that goes to my HVAC Air Conditioner condenser. I will measure, but I do think I will move the coax away from that line. That would be the easiest solution, but it doesn’t solve the 20M issue. The 20M yagi is as low as when I had a Moxon in the same location, but I am 100% sure that moving the yagi and getting it from 27′ right over the garage to almost 50′ – where my N6BT DXU-32 used to be – will solve that problem easily. That RF field will be over the back yard – and I will have no antennas over the house at all.

I also had the KPA-500 and KAT-500 between having the ACOM 1500 + AT2K combo, and before the SPE Amplifier. I had no problems then as well. There would have been no choke in the shack. That would then only leave the tuner at the base of the 160M antenna.

I am betting on using a tuner in the shack where it has a choke at the input – and that having the choke there AND at the antennas prevented excessive feedline radiation. Here is a very good paper on answering the question – tuner in the shack or at the base of the antenna:

https://wv0h.blogspot.com/2016/08/tuner-at-antenna-or-in-shack.html

So, there is no real serious reason to have the tuner at the base of the antenna, and if it solves the Common Mode RFI problem, then I’ll be a genius – hi hi

I have to admit – I miss using a tuner in the shack – while having the tuner at the base is supposedly a lower loss solution, I do miss the convenience of just having knobs. I do NOT want an auto tuner because I have one in the SPE – but compared to the KAT-500, its range sucks. It really wasn’t worth the extra $$$$

I’ll follow this post up in a couple of days when I have the time to test all of this out.

And I am also going to move and raise the 20M yagi so its no longer over the garage. That one is very easy to solve.

In essence, I will be going back to the way I had things before all of this crap started happening!

Mysterious Top Band

160M is a riddle wrapped in an enigma propagation wise. VK9MA has been quite readable for quite a few nights, but he calls CQ over and over and hardly ever returns someones call. I don’t feel too bad because I hear many others who have been trying to get him for a week now.

I’m sure his RX situation is not good – that seems obvious. When I worked ZL and VK on Top Band – they were in their homes, and I am sure they were avid Top Banders with great RX antennas. I worked an H40 in Temotu who was easy – and he was on a one or two person DXpedition, but I don’t think he was in a tent with generators. I heard that the generators were causing the team some QRM – so maybe that’s it?

But then there was FT5ZM and VK0EK – which were extremely rough QSO’s but I had more confidence in them than I do VK9MA. Its the “cadence” that tells me this – not the signal level. Its one of those times where you feel like maybe your antenna isn’t working – but I snagged the VP2 DXpedition in a couple of calls just the other night. I didn’t need Montserrat, but sure was happy when it was an easy QSO.

Because it feels so futile, I think I will just listen until I hear him coming back to 6’s. We just haven’t had a pipeline with this one.