Switched Transformers (Great Input from Ed, AG6CX)

I met Ed at Pacificon this year, and he has built some very nice matching devices and also shares a love for Johnson Viking Matchboxes. Our discussions have really helped me learn, and more than just getting some validation on things that I am experimenting with – our discussions help push me forward in the learning space. I have also enjoyed such conversations with Andreas, N6NU and others – who understand the challenges of the low bands and trying to match where high power is used – especially on 160M.

Here are a couple of quotes from Ed that I really appreciate:

“Now sorting out the frequencies of the ham bands as you did in the few days since you posted the initial results, your conclusion is pretty much spot on: You could have a switching network to add the appropriate transforming balun in line. As for the 1:1 feedline isolation balun 1115dt, I would suggest running output of the 1:4  or 2:1 ununs and any other frequency on which you don’t need Rs transformation thru the 1115dt as it leaves the switching network for the shack. It adds the benefit of increased common mode impedance to the signals coming out of the 1:4 and 2:1,and should have no effect on anything else. I use several of Bob’s devices, 1:1, 2:1, 4:1. and 9:1 and they are just fine. He is knowledgeable and fair.”

I just happen to have the 1:1 version with SO-239’s at each end, so adding that is a done deal.

It really is great to get some validation for my approach. I have two antennas that are resonant and where I have nothing to do but use them – my DX Engineering DV-40-P and my home brewed 20M yagi – where I used a solenoid style coil as the hairpin – something Tom, N6BT taught me, and which he did on that fabulous N6BT DXU-32 that I used to have.

But one thing Ed said really has me thinking:

“Now, to specific frequencies, I had no way to expand your data around the ham bands, but note that even in the ham bands with steep resonance (Xs) curves,you encounter Rs not unlike those encountered in any shortened antenna, such as a mobile HF antenna where Rs typically runs in the range of a few ohms, despite a steep Xs curve, These installations use shunt-feed, relying on an inductor across the feed for inductance, and stray capacitance of the installation to translate the typical Zs = 2-6 ohms + jx.xx ohms to Zs = 50 +j0,0.”

I just happen to have this monster coil that Ed gave me – and what Ed is saying jives with what Andreas, N6NU has done with his Inverted L. I have tried a shunt feed before, but found that my coil stock was not exactly right. I have several Airdux coils – but I suspect that they were not wide enough. This monster coil that Ed gave me is something I am going to try before the UNUN’s get here.

Another thing Ed said:

“Nothing wrong with your network switching device, but you might find a length of coax addition that picks up 40 as well as 160 and 80. Who knows! That’s the great joy of out hobby.”

This is really fantastic, because I have to admit, I have never tried using coax stubs as transformers. I just happen to have two 75 ohm 1/4 w.l. coax lines that I was going to use to try to phase two 1/8 wl spaced shortened 160M verticals. That project was shelved, and it just happens that disconnecting the line that goes from the remote Ratpack antenna switch to the 160M Inverted L gives me a very easy little experiment. I have read countless pages in the ON4UN Lowband DX-ing book – where phasing lines, shunt coils and UNUN or other “impedance transformers” are all over that book.

In fact, I opened up the pages where Robye Lahlum, W1MK discusses his matching and phasing circuits. When I first purchased that book – his stuff seemed so advanced, I was overwhelmed.

Now that I have been experimenting “hands on” and because I have had such conversations with Ed and Andres, it is all starting to really make sense. Bob at Balun Designs has also been fantastic to work with. Not only are his products top shelf, he provides great support and is willing to discuss solutions and he also validated my ideas for this most recent set of little projects.

I posted the Smith Chart above because while Ed and I were looking at the Antscope plots where The R, X and Z intersect:

Embarassingly, I had never even looked at those charts, and maybe only ever looked at the Smith Chart much. The upshot is that just by having a discussion, I have learned these things:

  1. Resonant antennas are easy to match and deal with, non-resonant antennas are hard to match when you want a good match on multiple bands
  2. The “other” plots that you can look at on the Rig Experts Antscope are a must for such work
  3. When using coils and capacitors for a feed, you can’t have enough different components to try – and I will try that massive coil that Ed gave me soon
  4. Stub matching can have the same effect as using UNUN’s and other components – I will try this for sure now

SO, my learning continues and I feel like my discussions with friends who share the same interest really help me take that next step up the education ladder.

Thanks Ed!

Thanks Andreas!

Thanks Bob!

December in California

I might have spent my early years on the East Coast, but I have lived in California for almost twice as long as when I lived in New Jersey, New York and Pennsylvania.

Don’t get me wrong, I have very fond memories growing up in Newton, NJ and going to college in Lock Haven, PA, but the last time I was back east was 1991. I did go to Dayton this past Spring, so I did get close.

But I love the Western States and the West Coast the most. I’m also eternally greatful that my Father finally took that job at Lockheed in 1979 when he moved the family here.

Interestingly, I could have been born in Los Angeles. My Father, in  WWII, landed on the beach in Normandy on the third wave, fixed tanks and Jeep’s and ended up in the push to Stuttgart, where he was born.  When he came home from the war, he bought a Harley with dreams of heading for California. Kerouac was born The same year he was, so heading West was an  ambition for some in the Northeast at that time. Iam sure he would have ended up in LA, but after a serious motorcycle accident, stayed in NJ.

My Father was a machinist in the US Army, but that was only because he wasn’t allowed to join the Air Force – because he was born in Germany. Never mind that he immigrated when he was 4 years old. He did end up in the Aerospace business.

It’s a beautiful California Sunday morning, and it’s more like an East Coast Fall day. We are going on a nice 35 mile bike ride, and I’m musing about how I ended up here.

I feel blessed and very lucky to have landed in the San Francisco Bay Area as a Computer Science major out of college, and I am enjoying my career more than ever after all these years.

When I first moved here there were next to zero tech jobs in SF – they were all down in the real Silicon Valley, pretty much Santa Clara County. There weren’t even many tech jobs on the Peninsula yet.

Amazing how things have changed.

The KY6R Inverted L Switched Matching for All Bands

Schematic drawn by KY6R using Circuit Lab – an excellent web browser based tool.

I use the same relays as Array Solutions does in their gear:

Deltrol 20852-81 12v 35a DPDT – $13 at Galco

I went over the Rig Experts AA-30 SWR plot and found that on every band from 160-10M, one of three UNUN’s or 1:1 Curent Choke will keep the SPE Expert 1.3K amplifier happy. This means I wouldn’t need the Palstar AT2K – at least this works on paper. I just happen to have this control box in my junk box – where the RCS-4V remote switch burned up, but the Control Box can be re-purposed for this project:

Because it injected AC to control the remote switch – using the coax as the control line – I have to rework it a bit and probably remove a few parts or even cut some pads on the PC Board:

The rework . . . and here’s what the new (and simpler) circuit looks like:

Position 4 isn’t used – but could be used for another UNUN or Balun, maybe for a ladder line fed doublet that I might throw up in the trees – like maybe a 17M extended double zepp – pointed at 3Y0Z.

Array Solutions rates these relays at 5 KW- I’m not sure how they calculated that, but I have used these relays before on my Inverted V / Marconi switching, and since these re what Array Solutions uses in their Rat Packs for years with no issues, this will be a fun project to try.

I will have to come up with the voltage matrix. In short:

BAND LO/HI Rotary
160, 40, 20, 15 DWN 1
80, 17 DWN 2
30,12,10 UP 3

 

The Ghost of Nixon Past . . .

Its downright Dickensian . . Karmaic Justice is about to be served up on an icy cold tray. But unlike Scrooge, or the Grinch, don’t expect Trump to grow a heart.

It is really amazing how close to what’s unraveling in the news today was nailed by Bill Maher and his crew. They deserve an Emmy or Pulitzer or whatever award they give TV shows. Its also amazing that Trump – with all his tweets pretty much gave it all away anyway – loose lips sink ships. His firing of Yates, Comey and Bharara was straight out of “The Gang That Couldn’t Shoot Straight”, “The Soprano’s” or “Dog Day Afternoon”. House of Cards is waaaay too sophisticated and intelligent. Its amazing how such pathological narcissism can become your own downfall – not only is all this Dickensian, its Shakespearean.

One thing I know for sure – people don’t lie if they have nothing to hide. They don’t fire people investigating them.

Ironically, besides all of the Russia related news that will now pour out – the real serious issue is that Trump cannot do the job – he is so out of his league and incompetent that its time for him to go. My father suffered from dementia before he passed, and I took care of his affairs and visited him several times a week. The strange tweets regurgitating old tweets from a year ago about the Birther thing and Access Hollywood mixed in with all kinds of new weird tweets this week just seem like what I experienced with my father but times 100.

http://www.nydailynews.com/opinion/donald-trump-madman-article-1.3665163

I would not be surprised if the 25th Amendment will be invoked because there is no way the GOP will have a chance during the 2018 mid terms if they do nothing or stand by Trump. Now I’m wondering who else will be nailed – it seems like there will be many indicted now.  Its going to be flip city.

I actually think what will now be a torrent of facts and dirty details will cause the GOP to have a very, very bad 2018. Of course, maybe Trump is their “foil” – maybe he runs interference for them. That’s OK – they will pay dearly for letting treason and collusion stand. We saw the seed of that sown just last month. In some ways I say – leave these assholes to their own devices, but the dems better get their shit together, and better get some young and very powerful blood up front. Their 80+ year old leadership is looking way long in the tooth.

I expect all kinds of weird tricks and legal maneuvers and Twitter rants and threats to happen in response, but its already too late – irreparable damage has been done. Politically, this has been the worst year of my life and I truly worried that our democracy was toast – but now I am thankful that justice might finally prevail. It may take way more time than any of us can stand.

My prediction on this tax scam for the rich – I think there will be as much blow back from it on the repubs as there was against ACA for the dems. Round and round we go. I also do believe we will have a repeat of the Bush Years. 

After 2 years of getting a tax break, the GOP takes it all back and more. The idiots in this country will put Trump on the right hand if God, knocking Christ and the Holy Ghost out and the idiots will then wonder what happens in 2 or so years when the well runs completely dry.

Get ready for that!

 

 

Switched UN-UN’s for the Inverted-L

If it weren’t for 80M, I could continue to just use the Balun Designs 1:1 current choke at the base of my Inverted L. One way to make my Inverted L happy is to put a Vacuum Variable Capacitor in series to the vertical – and use the AT2K Tuner in the shack. Tune the capacitor remotely as I did the URAT.

The second option, which is perhaps easier is to switch in one UN-UN or another, and this is so I can use the antenna on 160 or 80 (schematic above).

The Balun Designs 1435t UN-UN is a 1:4 model and would step the 80M 7 ohms j27.4 up to 50 ohms.

The Balun Designs 2132u is a 2:1 UN-UN and would step the 194 ohms j213.4 on 160M down to 50 ohms.

I am going to try this. It might just turn out that all I would then need for 160 and 80M is the SPE 1.3K built in ATU – which has a pretty small range, but these UN-UN’s most likely would make the tuner happy. I would still need the AT2K if I wanted to use the Inverted L on say 30M or some other band.

Speaking of other bands – the 3Y0Z DXpedition will most likely be good into the West Coast on 17 and 15M, and while I am pretty sure I will get them on 40, 30 and 20, I might try them on 17 and 15 using the Inverted L.

The switching circuit you see above is approximate – I might even add two more relays to switch in a 1:1 current choke instead of the 2 UN-UNs only because then I would be able to cover pretty much any band from 160 – 10M.

I could wire the control voltage so that one “line” is a default switched in line and all others are closed. The natural default would be 160M. Then with basically a simple rotary switch – I could control the three different “chains”.

I could even use an Arduino or Raspberry Pi Zero W to control the relays via WiFi if I wanted to get fancy, but because I still have to run a control line for remote power, I will just hard wire it and control it with a rotary switch. The rotary switch simply sends the plus 12v line to activate each pair of relays – I think I will everything to be normally opened, and then when I switch to a position, it switches in the relay pair for each matching transformer. I like instant switching, so, maybe this would even mean I would no longer need the AT2K at all. I can easily test my assumptions and then use an old Ameritron RCS-4V switch box controller that I have in my junk box (where I burned up the remote relay board) that has a rotary switch and leds and just do a little re-wiring.

I’m going to try it and see – it will be a lot of fun.

 

Inverted L High Resolution Plot

I have not taken a new plot with my Rig Experts AA-30 since I changed the antenna from more of a traditional Inverted L to this “inverted fish hook” configuration, so I decided to set the range from 1700 – 15000 khz and see if its any different than the old configuration:

This the OLD plot – when the antenna was a standard Inverted L, and here is the new plot – this time just covering 160 – 20M:

There is a little difference, but not enough to make the antenna appear much different to the Palstar AT2K tuner in the shack – or to the 1:1 current choke at the base of the antenna.

I’m also going to send the plot to Bob at Balun Designs to see if maybe an UNUN might be a better choice than the 1:1 current choke. I doubt it will, but I thought I’d ask – since this is Bob’s expertise.

80M is the only problem band – and I’m thinking maybe I could use the 1:1 current choke on 160, 30 and other bands, but switch in a 1:2 UNUN for 80M.

I’ll update this post after Bob gets back to me. I highly recommend Balun Designs products – Bob is the nicest guy and builds superb quality products at a fair price.

The KY6R Year End Review

I was going to wait until the end of December to write this, but know enough about how this year is likely to end to write this now.

The year started out with the cloud of the election hanging over me. I grew up in the New York / New Jersey / Connecticut tri-state area, and knew all about Donald Trump when I was growing up in New Jersey. All of my friends – Democrat and Republican – always thought he was a shyster, a joke and a schmuck. We had a name for such a person – “Showboat” or “Blabbermouth”:

Even my Republican New Yorker friends jokingly said “We warned you!”.  Politically, the year seemed very, very grim, but I took big solace in Stephen Colbert’s Late Show but this one segment by Bill Maher (fellow New Jersyian) is and will always be a (telling) masterpiece:

Trump has made comedy great again, and there are two things that strike me as critical in the US:

  1. Screw the allegiance to either political party – remember how both parties have their Billionaire Donors and how our government is truly a Plutocracy or an Oligarchy. Our government is more “bought” than ever. Pick your billionaire – that’s who you are really voting for
  2. There are the 99% and the 1% with a dwindling Middle Class. The Middle Class has always been the back bone of this country, and I fear as we continue to marginalize the Middle Class that something has to give. I do fear where this is headed

Forget about politics – Trump is exactly the person I taught my children not to be. I was taught The Golden Rule above all else – both in Church and at school. My rant is much more about Civility rather than Politics. This is because I’ve lived long enough to have been under both parties almost equally, and I’m still alive to talk about it. We will always switch back and forth – but we at least always had a modicum of civility – and that has gone AWOL the last several years. Its a really bad omen. I feel like we have hit full on “Idiocracy” in the USA.

In time – Trump will only be a historical bookmark, and he and his family will be viewed as the political  bottom feeders and history will be terribly unkind to them and their “brand”. But even when we are finally flushed of the nasty “Twitler” and his bullying (and way too much daily news about this epic Pathological Narcissist) – we will still have the problems we have today.

As a result of the nastiness, I gave Facebook and Twitter the big boot, and not only do I not miss them, it has given me great relief. At some point I got overloaded by commiserating with friends about the current administration.  I also realized that we get the administration we deserve and that if people want change – we the people  will have to make it so. Trump’s core is aging and will become a minority both as they rapidly start going SK, and as younger generations pick up the mantle. Demographics will create a new world – but I don’t know exactly what that will be – but I expect there will be a yuge bigly shift to a very progressive society. Its not going to be nirvana though – the problems will just be a different shade of grey. I will be retired by then, so my station in life will be quite different. I will be far away from a major metropolitan area.

As always, a very bright side of life is Ham Radio and getting into the 90’s toward 160M DXCC and 9BDXCC. At this writing I’m at 91, and after hoping for a boost from the CQ WW CW contest and it being a total bust, I realize that my new goal is to make 100 by the end of next year. A miracle could happen, but the “cadence” suggests otherwise.

In the spring I re-landscaped a chunk of our front yard, and the last plantings were in the fall, and were two trees that will replace two that are about to fade and die.

Shortly after the March re-landcaping, I started work at Credit Karma in San Francisco. It has hands down been the best company I have ever worked for since I graduated college with a comp sci degree in 1981.

Antennas are a big part of my life, and there were three I worked on. This one is the “Mod Bob” or Modified Bobtail. It is a great lowband antenna, that when coupled with a Palstar BT1500A at the base / feedpoint, is something to consider. That antenna led me to my first big “Ham Maker” project, the URAT (Universal Remote Antenna Tuner):

I have never learned more than what I did from the Mod Bob plus URAT – at least not in Ham Radio Landia.

In a surprise move, with only 3 weeks before Dayton Hamvention, I booked a trip at Bob, KK6EK’s urging, and was very proud to be on hand to receive the DXpedition of the Year award sponsored by SWODXA. That seemed like the icing on the cake – but we then won DX Coffees “Best Communication Award”. I was honored for my behind the scenes work, and it was really nice to have been recognized as the DXpeditions “5th Beatle” so to speak.

During the summer, I built a small “maker space” to the right of my ham shack radio operating desk, and I have built a couple of small projects just for fun – like this Field Strength Meter:

We went to Montana for a very nice late summer / early fall trip:

I also tried FT8 – which is the only digital mode I like:

I did later realize just how much more I like CW than any other mode . .

After a fall firestorm scare that took place up in Napa and Sonoma counties – and where we had some of their same weird weather for those 2 weeks or so, things calmed down and we had our super display of autumn leaves, and we even started to get rain

.

I had a couple of late year antenna projects – replacing the Mod Bob with an Inverted L:

and moving my home brewed 20M yagi:

But more than anything that has happened this year, we had just the best Thanksgiving, and more than anything else in my life, my family is and always will be the most important thing in my life:

So, what’s up for 2018:

3Y0Z is the only thing on the Ham Radio calendar. I do expect to work them and then being only 1 away from Top of the Honor Roll. I plan on “puttering” more in the ham maker space and learning how to use my Oscilloscope and Signal generator. I’ll continue my “living history” pursuit in my reading and visiting museums, and I have some really great projects lining up at work. My Data Dictionary project is really taking off.

We will visit Bend, Oregon, but besides these things, I do expect to make 9BDXCC and DXCC on 160M – but at this point it could be the end of 2018.

I used to like to try to guess what might happen – but – besides the DXCC and work stuff – I have no big prognostications – although there will be high drama politically – but even that has “ho hum” in a way since all of the “sensationalization” of the last couple of years has left me numb. And in 3 years it won’t matter much anyway. It will be interesting what happens in the 2018 elections – will there be a “Blue Wave?” I say yes – but the Democrats better put up a 2020 candidate who is the counter to the mess in office we have now.

Family health, happiness and well being is really the only thing that matters, and I always pray we continue to do well in this regard.

Cheers to you and yours – I wish you all the best in 2018!