Posted on April 11, 2019
I have had much better luck at my Lafayette and Orinda QTH’s than I would have expected. This illustration – from the ARRL Antenna Book tells the story. Both QTH’s are right where the “Best” is shown. And both QTH’s had the down slope to the West and uphill to the East. Both were pretty good from 0 degrees going counter clockwise to 180 degrees – maybe back around to 130 degrees. Both had problems from 0 degrees to about 130 degrees going clockwise. Lafayette was better than Orinda because it was in a wider valley – in Orinda I am in a narrow valley, but it seems that the hills to the north, west and south are just far enough away to send and receive signals down to “low enough” take off angles.
Well, its very obvious that I will never experience the same low takeoff angle signals at my Orinda QTH that someone would at a flat field or better yet a salt marsh near a beach.
The two hills are East and West, and the North and South are where Moraga way goes through – and there is a down slope to Orinda – which is due North, and slightly up hill toward Moraga – which is Southward.
This diagram makes even more sense than it did way back when – when I generated it. You can really see that at 14 degrees takeoff angle – I am “shadowed” by the hills to some degree all around – but severely to the Northeast. HOWEVER, all of the antennas that I am building are nominally 20 degrees take off. This also now completely explains why my DX-ing buddies who live closer to the San Francisco Bay – or in the Central Valley flats do better than I do.
Also, my friend and neighbor Oliver, W6NV has a QTH way up on a hill – just below one of the tallest ridges in the East Bay – so he has a very low takeoff angle – and I was blown away when I made a QSO recently when we were plotting for me to work Bouvet from his station. In fact, out one window – he basically looked down on my QTH off in the distance.
It was the most graphic experience I had comparing one QTH vs. another. He and I agreed that for my last two ATNO’s it is time for me to stop beating my head against the wall, and instead, use his station.
Its nice to have a “DX Elmer” even after I have made Honor Roll. Its like having a big brother in that respect – and the social aspect of DXing is really nice. I had been going it alone all these years – I’ve shared my experience with others, but never asked anyone else for anything. So – it feels good to have ham radio and DXing friends in “high places” – heh heh.
I’m not going to Visalia – I just haven’t been into “ATNO DXing” now for about 3 years – VK0EK was the last big deal DXing for me – albeit 3Y0Z and 3Y0I could have rekindled some excitement. I did make DXCC on 160M which also qualified me for 9BDXCC, but even there I’ve sold all my low band RX antenna gear and replaced the 160M TX antenna with a 75M vertical for nets.
Well – maybe, just maybe – the French Team will announce Glorioso? I do think the 3Y0I guys will try again – and I do think they will finally make it – maybe this October – its just a gut feeling – they have a lot to prove and they seem crazy – motivated to make their mark. I do expect that they eventually get the fanfare they seek.
Here’s hoping there will be some exciting news from Visalia in a few days.
Posted on April 11, 2019
The width of a 40M 5 element Bruce Array is the same as a 3 element Bobtail – 140′
The 5 element Bruce just doesn’t cut it when compared to a 3 element Bobtail – because you get the same gain and takeoff angle but with a lot more complexity as far as putting the thing up
Yeah – the 4 element Bruce Array vs. the Bobtail curtain is a better match up – if I really can’t fit the Bobtail in, the the 4 element Bruce is a better choice.
Well, I will have to run a line from the end of my lot where I have a redwood post cemented in the ground and look at where I could put one next to the creek – and then really see exactly where the bobtail could fit vs. the Bruce.
It will come down to – is it easier to use all wire for a 4 element Bruce hung up in the trees – or use three aluminum verticals mounted on redwood posts and connected with top wires.
I am pretty sure both will require some tree branch trimming – but as long as neither require cutting down any trees – then there is a real “shoot out” coming up soon.
Posted on April 10, 2019
As it turns out, the space I have for a 40M Curtain Array is great for a Bruce Array, but problematic for a Bobtail Curtain
The width of the Bobtail Curtain is 140′, and there are two problems in my back yard:
- The feedpoint would be in a really bad location – too close to the house
- The farthest element would require that I cut down trees next to my creek
Luckily, A Bruce Array – with 4 elements happens to have the same gain and pattern as the 3 element Bobtail, and is 1/4 wavelength less in width. This means it is 105′ wide, which will fit perfectly in my small and odd shaped property.
The feedpoint (shown as the blue circle) ends up being in the perfect position – it’s where my DX Engineering DV-40P feed and control wires are routed to my 2 element 40M vertical array (today). It also would end up being a perfect place to insert the Collins 180S-1 L tuner at the feedpoint of the array. I would have everything I need – the control wires would control the Stepper motors. In fact, I could even do an A-B test between the DV-40P by leaving that array alone and hanging the Bruce from two trees that would support the 40-ish foot high (elevated Bruce). I could feed it at a 50 ohm point for the comparison test – and that coax would be at 90 degree angle away from the antenna to the remote RatPack antenna switch that I run all antenna coax into – and then just one line into the shack.
I could even feed it using what is my 80M feed and control wires – because the Bruce can be used for 75M local phone nets that I check into – since it would be a perfect NVIS antenna
It turns out that the funny Bruce pattern avoids trees in each “bay” almost perfectly. The third element is closer to the house (and shack) than I would like it, but all of the elements end up in the clear – which is a real feat given all the trees and my creek and my house.
Before I “fell into” the Collins Gold Dust Twins late last year, I had a $50 deposit on a new Yaesu 200 watt rig at DX Engineering – so I just switched that deposit towards 300 feet of their excellent 14 gauge antenna wire (same as Flexweave – which I think is trademarked by Davis).
Posted on April 10, 2019
Bouvet is most definitely in the path of the new Bobtail Curtain
Tromelin – and maybe even Glorioso could happen on the NW path
I remember an avid DXer told me that there is a special path where you can work towards the French islands near Madagascar towards my NW. This does seem to be the case, and so that gives me even more reason to try this. I do know that JA’s on the NW path are always very strong – but distance wise, they are much closer than FT/T and FT/G.
I did work FT/T very easily during the last activation – I even forget the call now – that’s how out of it I am as a DXer. I’ll have to check my log, I do know with the DXU-32 and full power I got in the log the first night and after only a few calls on 20M, and because it would have been light to our West, it had to be a Western QSO. Tromelin is almost at our Antipode, so LP and SP are pretty much the same distance. I guess I could see NW or SW being possible, heck maybe even NE and SE when we are both in light.
But it could have been this NW path the fellow told me to try.
On 40M it would have to be West during our sunset and East during our Sunrise.
But yeah, I am really committing to building this 40M Bobtail Curtain. Its what I will also dedicate to the KWS-1.
Posted on April 9, 2019
The 40M Bobtail will be perfectly aimed for Bouvet Island
Elevating the antenna 10′ offers a lower takeoff angle and makes it easier to install hanging from 2 trees that can support the height
It just so happens that I have two trees where I could get the Bobtail up off the ground about 10′. Switching to all wire elements changes the geometry a little – the elements need to be a little bit taller, but with the same spacing.
Forget about NE and SW directions – there are deep nulls in those directions
This is probably OK at the bottom of the cycle, and certainly good for Bouvet – which is the only ATNO I will have a chance at working for the next 2 years from Orinda. I don’t even worry about more than 2 years any more in my planning – I might not even be at this QTH after that. This is also the last time I will have a chance to try this – so I will do it – probably in late May / early June, when the grass is dried out and I can weed whack and move around more easily than now.
This is the center connection – with a possible elevated counterpoise (not sure yet)
I will definitely use the Stepper Motors and drive them with either an Arduino or Raspberry Pi board and Stepper Motor drivers. I will also go for memory settings for multiple bands. The antenna is only a mono bander, and a cloud warmer on other bands – but for checking into the nightly Mission Trail Net on 75M, it will be fine.
My remote tuner that will be driven by Stepper Motors
I have scaled this for 30M, and while it fits in my lot much better, I think 40M is just a much more productive and interesting band – its by far my favorite. I also can use the KWS-1 on 40M (it is a pre-WARC rig)
The U.RAT – the forerunner to what I will do this time
The Collins 180S-1 – the absolute perfect antenna coupler for this application!
OK – this is a very cool project, and I am again excited to have an antenna idea that I can squeeze in my lot. I have to try this once. I was able to talk to an East Coast Ham who swears by his. Its a leap of faith – because the DX Engineering DV-40P has been so excellent – but I get to try to push the limits one more time while I am still at this QTH – so now my idea finally is justified . . .
Posted on April 8, 2019
Google Earth still shows my old N6BT DXU-32, which was one of two best antennas I have ever had as far as DXing, performance and convenience are concerned. Convenience is relative – that was one big antenna, and I am kind of surprised it did so well on top of a military mast – the AB-577. A testament to the engineering feats of military grade hardware. It actually scared me when I took it down – I realized how dangerous that was – if anything happened and the antenna crashed onto the roof. Yikes!
Anyway, this post is not about that – its the only place I can squeeze a 40M Bobtail Curtain – along the creek that defines the hypotenuse of my property line. It would end up being just fine for ZS and 3Y0B entities, and that means in the other direction, JA. It would have a deep null in the NE polar path and SW, so that kind of kills Glorioso – but I’ve been fixated on trying a full size 40M Bobtail for some time now.
I know even a dipole up 70′ would be better, but that isn’t going to happen. The 2 very large trees that used to be available (on my two neighbors properties and which I did secretly use without then ever knowing) have been cut down – they were “weed trees” – Monterrey Pines, which suck as far as trees go – they get tall and very dangerous as they get old. They were meant to be along the coast – not 20 miles inland where its too hot and dry for them.
Anyway, I’ll have to think about this a while. I sure wish I could talk to someone who has had experience with a 40M Bobtail. W8JI thinks Bruce Arrays and Bobtails and Half Squares aren’t all that great – but I have had very good experience with the Bruce Array – when I had a 4 element at my old Lafayette QTH, and here in Orinda, the DX Engineering DV-40P has been a solid performer.
If you have had experience with a Bobtail Curtain – let me know what you think.
Posted on April 8, 2019
This graph is from a very interesting web site – http://users.telenet.be/j.janssens/SC24web/SC24.html
I know that we have already had a Cycle 25 sunspot, so it will be interesting how long the minimum will be between Cycle 24 and 25. This graph shows how unusual Cycle 24 was at its bottom. It was deeper and longer than the past three cycles.
This is one of the better web sites to check out if you are wondering what might happen between now and the peak of Cycle 25. One big take away for me is just how abnormal the bottom of Cycle 23 was, and that the bottom of Cycle 24 might not be as deep or long as Cycle 23. How high will Cycle 25 go? That is too hard to tell – but I remember how ridiculously all over the map the predictions were for Cycle 24, so this is a “just wait and see” thing for me.
I am now convinced that I will get one last chance to work Bouvet (I am sure the 3Y0I guys will try again – all of their pride is wrapped up in this, and I have learned from “driven” DXpedition leaders that once they fixate on such a project, it does happen). My only hope is that the 3Y0I and some of the 3Y0Z guys would work together and also do a proper fund raising. Go next October and make it a success. I think its time for everyone to join forces, and that the clubs and foundations need to support whomever goes. But for that to happen, the 3Y0I and 3Y0Z teams need to put aside some of their attitudes.
I also expect that the French Team will activate Glorioso – but that it will be the last time that entity is activated in my lifetime. This means I very much expect that if you started DXCC today – the probability is you won’t make it to Honor Roll #1, and I even think making Honor Roll wouldn’t be possible. I knew things were trending this way, and the numbers aren’t there to support these activities moving forward. There are just way too many entities that are too expensive or environmentally hard to access. Just as important is that the number and age of “well healed” DXpedition Teams is dwindling. More will have to come from non US countries, like 3Y0I, but without US Foundation and Club Support, good luck.
I’ve decided after visiting my neighbors awesome ham radio shack (and having some fun socializing at the same time) that ending my Honor Roll #1 pursuit at another shack is what I will do. I’ve worked all the rest from my own shack, and sure – I will also try to work these from my shack, but also won’t do what I did with FT5GA – suffered without a peep from them at my shack while others ran up to the Stanford ham shack and worked them. I don’t need this purist BS any more. I’ve moved on to just having fun – DXing definitely started feeling like work and not fun – so that’s the reason I decided to move into a new area – the vintage gear space.
And in getting into the vintage space I have made new ham radio friends. I love the passion in each of these genres – they are like their own little worlds, and they are all interesting and fun to check out – kind of like going to your favorite amusement park when you were a kid. Lots of fun rides – my favorite amusement park was the Boardwalk at Wildwood at the Jersey Shore . . .
I do expect that I will get serious about QRP and CW – that is waiting in the wings after I get the KWS-1 on the air. Of course, I am always dreaming of antenna projects, but there is only so much you can do at your QTH – and I know I won’t be buying any big properties when I retire, so in a way, what I am doing now at my QTH is about the speed of what I will be doing when I do leave Orinda. I will certainly make sure I don’t move into a place with HOA’s and CC&R’s that preclude at least a flagpole vertical or a wire up in the trees. But the plan will be to bring the US Towers ALM-31 Crank Up tower and SteppIR UrbanBeam.