December 22, 2014
Carrying on from the last blog post, here is the Orinda QTH with a 270 degree (West) to 90 degree (East) panoramic side view:
This is the Oakland that goes from the San Francisco Bay at the left (West), to the Oakland Hills to the right (East). But the Oakland Hills (Skyline Boulevard) is far enough away to launch signals in the North to West and into the South East which explains why ALL of the HFTA Plots in yesterdays blog post looked so much better than the Orinda QTH – which is shown in the top panoramic side view. Lets look at the two combined, just for laughs:
All the way to the left is the San Francisco Bay, and its really amazing how two QTH’s less than 10 miles away can be so different propagation wise – due to surrounding hills. Just for fun – I overlaid both the Orinda and Oakland QTH’s azimuthal plots with my “needed” world map:
From this – you would gather that Oakland has the big advantage only to the Northeast, but having looked at the “devil in the details” in yesterdays blog post – we know better.
I’ve made it so far toward my goal – and with only 6 more to go (5 that will be activated again and one at this point I hope _something_ happens), it wouldn’t make sense to move over the hill. I guess you could say that the “optimistic spin” on all of this is that a really crappy DX location will force you to really dig deep and search for answers – and then you will either design and create a system that works for the given situation – or you will move or go the remote route.
There were many, many QSO’s where my good friends in Oakland and Berkeley could hear the DX on antennas either similar or lesser to mine, but where the copy at my QTH was marginal or ESP.
On a few occasions I had been chastized for being an “alligator”, so I did improve my antenna system – more gain, directivity at a much greater height, and then I pulled myself up out of the “swamp”.
December 22, 2014
First off – I want to thank two very good DX-er friends – Stu – K6TU for helping me with the analysis and generating some of the data, and Dean, N6BV for his awesome HFTA program.
I own a house in Orinda and Oakland. The question is: “Which is the better DX-ing QTH?”.
Here is the HFAnt plot for my 3L 20M yagi up 55′ in Orinda:
Here is the same antenna at the Oakland QTH:
These plots show a major difference in the NE direction, and it seems like the Oakland QTH is the clear winner. Now lets dive deeper – and put these QTH’s under the “HFTA Lens” and use the entities that I still need towards DXCC Honor Roll #1:
FT/G on the Short Path – the Terrain:
Oakland has the Skyline ridge and hills 2 miles away, but in Orinda, there is a serious
“wall” of a hill just across the street from my house. Here is what HFTA says signal wise:
Amazing. Oakland wins big time. Lets look at K1N – Navassa. This one is only a short path concern:
Clearly Oakland wins the Terrain war. There is so much more space to launch a signal, so lets look at it signal wise:
Oakland is light years better – it doesn’t even matter what the “FOM” is. The number of low angles and the gain at those angles is so dramatically better, there simply is no contest. Onto Bouvet, 3Y0F:
Oakland does clear the hills better, but the difference seems closer in this direction than others. Lets see signal wise what happens:
Oakland wins again – hands down – because the hills are not nearly as close in as they are in Orinda. Now lets look at VP8/S – South Sandwich – where there is even less of an issue with hills in Oakland – but they hamper the QTH at Orinda:
And the signals in Oakland would be very seriously better:
And now Heard Island, VK0EK:
Again – no contest – Oakland wins in a HUGE way.
Not that it will ever be activated, but Kingman Reef, KH5/K looks like this:
And the signals:
Geez – I really need to move to my Oakland house and rent out my Orinda house!
December 20, 2014
On Sunday, December 14th, ten hearty souls showed up at the Cordell Expeditions warehouse in Richmond, California. This is less than a mile away from where Kaiser Steel and others had ship works going during WWII – building big ships for the Pacific Theatre of the war, and about 10 miles away from where Emelia Earhardt took off on her final flight.
We prepared for VK0EK, The Heard Island 2015 DX-pedition. Since pictures and videos speak far louder than words, enjoy the show – the hard work – DX-ers talking DX, and the awesome camaraderie!
Back Row, L-R: Jim, N6TQ,Mathison, KJ6DZB, Eduardo, K6EGF, Rich, KY6R, Elliot, N6PF, Mike, KJ4Z
Front Row, L-R: Jack, K6JEB, Peter, W6DEI, Jim, KI6SDF
Our good friend, Phil, operating “The Elevator”
Lunch Time with Doctor Bob, KK6EK . . .
Dx-ers talking DX!
December 18, 2014
Very exciting news this week from the Intrepid DX Team regarding their announced VP8 DX-pedition to South Sandwich and South Georgia. I already have South Georgia, but South Sandwich is an ATNO for me, so this operation could combine with everything else you see listed above to get me as close as being only 2 away from DXCC Honor Roll by my 57th birthday in March, 2016.
I will send my “normal” $100 donation since this is an ATNO today. I hope many others do the same. I hope DX-ers really open their pockets with all of these really rare DX-peditions taking place. I also hope some of the younger DX-peditioners start considering Polar Entity DX-peditions – because the challenge of activating such is extremely challenging – and several of the current DX-pedition leaders are entering their 70’s. Younger blood will need to take up the charge the next time you see these activated – and this will be a very big change in the ARRL DXCC Program for sure. I used to think some of these won’t be activated “ever again” – but I think as long as younger DX-peditioners take up the challenge – these will continue on – albeit not very often. South Sandwich was activated last – VP8THU in 2002 and VK0IR – Heard Island in 1997. Bouvet was last activated in 2008, but with very few QSO’s.
Maybe global climate change scientists will establish bases in some of these rare ones? (Little humor there).
The only two that would be left would be FT/G – Glorioso, and KH5/K. I’d be sitting around for a while at that point – I doubt anything will happen for years regarding Glorioso or Kingman Reef, and I will not count on Kingman Reef ever being activated again.
With all of these planned DX-peditions happening, Kingman Reef will most likely rise to #3 on the Most Wanted List. I don’t expect the ARRL will do anything with Kingman Reef until it sits in the #1 Most Wanted slot for years. I actually expect that I will work Glorioso before that, leaving Kingman Reef the last entity keeping me from DXCC HR #1. I do expect that something will happen with it eventually – but until then, I will enjoy ticking off as many as I can along the way to HR #1.
December 17, 2014
My good friend, Baptiste Hermange, F4GXX, asked me if I thought stacked Moxon’s would work. The answer is “it depends”. Lets look at two 17M Moxons with the bottom one up 28′ and the top one at 55′ – and these are phased with a simple Array Solutions Stackmatch II:
The gain is very nice – 13.39 dBi at 15 degrees takeoff angle. Here is the azimuthal pattern:
The front to back isn’t as good as a sinlge Moxon – only 14 dB, but look at the top elevation plot – there are no overhead lobes. Stacking supresses the overhead lobes and seems to “squeeze” the takeoff angle to a nice 15 degrees. If you don’t connect both to stackmatch – the top antenna does well – decent F/B, but with some reduction in gain (not enough to worry about), but the bottom Moxon does not do well at all – a big reduction in gain and F/B. Now – this is probably because they are spaced 1/2 wavelength apart.
I tried the same thing – stacking the bottom moxon closer to the top, and things really degraded. So my first conclusion is – if you stack two of the same frequency moxons 1/2 wavelength apart – and use a Stackmatch – you can stack and see some gain improvement.
OK – lets try two different Moxons – a 30M moxon at 60′, and a 20M moxon at 50′:
A fairly similar thing happens as in the first case. The top Moxon has decent F/B but reduced gain – but still “close enough” to a regular moxon. The bottom moxon is impacted more – less gain (10.5 dBi only) and less F/B (15 or 16 dBi). But the patterns are still directional and still “decent” DX antennas.
With the 20M moxon over the 30M moxon, both antennas pretty much retain their very good characteristics – the antennas in this case are 48′ for the 30M antenna and 60′ for the 20M antenna.
Here are two 17-12M nested Moxons stacked over each other – separated by 1/2 wavelength on 17M:
Stacking the same nested Moxon’s over each other and separated by 1/2 wavelength on the lower frequency band works VERY well. But when I tried to stack to sets of dissimilar Moxons – there was more loss. If you want to do this – its OK – stack the smaller nested Moxon over the larger nested Moxon – but you will suffer more gain reduction in the lower nested Moxon, and the top one will be OK. You really have to use EZNec to get the right spacing though – its much trickier to try to stack “dissimilar” Moxons than similar moxons – that is for certain. I question all of the extra work with hardware that would be needed just to mount these. It seems like a lot of work. When I had a simple stack of two 2 element 17M aluminum yagi’s – it was a lot of work, and at my QTH, the top antenna always outperformed the bottom, and even outperformed both switched in. Why? Because at my QTH height is EVERYTHING. Living down in a bowl means I need to get antennas as high and in the clear as possible. If you are lucky and live on flat land – or on top of a hill – you will have different results.
What would I do?
If I wanted multiple bands in a wire antenna, I would buy this antenna and mount it as high as possible:
This is a beautiful wire beam!
December 14, 2014
December 11, 2014
Here is the latest K6TU prediction for February 2015 and K1N. It sounds like they will activate the last week of January – or maybe early February – the dates are still pending.
I just had a quick and easy QSO with a J6 (“close enough”) to KP1 at 2200 UTC. Right now its their gray line, and with my 20M yagi retracted down to 40′ (from 55′ due to this storm):
The sun will only be a wee bit different during the first week of February (since the Caribbean is closer to the equator):
For the West Coast it won’t matter – there are no times when there is an advantage during the gray line. The “proximity factor” will be what makes K1N so workable.