Oct 21, 2009

The MPV project

"Most Pitiful Vertical"

It's time to become active on Top Band again!
Since the move to my new QTH there have been several options investigated on how to implement a vertical antenna for 160m. Discussions, software antenna models, wild ideas etc.. all with no result yet.
A recent article in QST described a "No excuses" home brew vertical by John K6MM. This helically wound vertical is only 25ft(7.6m) high, see details at his website
Sure, delivering a puny little signal this is no pileup-killer. But you make qso's and at right times you work some dx as well.
So why keep dreaming about that larger, but still compromise antenna in the woods behind the house, which by today remains not feasible and due to practical restrictions will still be a compromise?
Then there's this remote farm site available for serious 160m operation, but that's more than an hour drive from here. You want to check Top Band when you pee at nights right?. Maybe I can have fun even with a ridiculous small antenna.

On october 14th there was a cool presentation during a joint webinar from PVRC-NCCC by K6MM.


The MPV idea
Let's put up a vertical and see what I can accomplish. I sure can use the experience for future field operations. There is and have been so many reasons in the past to not put up a small vertical for 1.8MHz, both at home and on field locations.
As my garden measures only 8x7mtrs (600sq feet) there is another requirement: the vertical must be unobtrusive for the neighbourhood during daylight hours. This means I need to be able to take it down to a max 3m(10ft) level in a matter of minutes.

First steps
From DJ6NI I have the 10m version fibre-glass mast for more than 10 years now. It has served me on many occasions as mast for antennas like Inverted Vee, Vertical, K9AY etc. This very tough material and can carry a lot of weight. Each section can be locked and has a micro adjustment.
Why not install a 12, 18 or even the new 26m Spiderpole fishing rod? I have seen that big sucker at the Friedrichshafen Ham-Fair, but the 15 segments become quickly too heavy to lift. It's ok for any field day occasion, but not the daily install I have planned in my backyard. Not to mention it costs 549 euro.




Result
10m heavy duty mast. Can be set up within 2 minutes at minimal effort.
The top section is 22mm dia so there's opportunity for additional length.
Guying is done at the 6m level, using 2mm dynema.


No; for several reasons there is no possibility for a vertical in those trees behind.


Next
  • Find an extension like old fishing rod
  • Explore option for possible inverted L
  • Or helical windings
  • Create ground screen
  • Find the final resonance and add a tuning network at the bottom
I need to clean up the garden first.






Oct 18, 2009

Goal for 2009 season
Like every year I do set reasonable goals for the 6m season. Yes; 'season' because outside the Es-propagation window of may-august, there's nothing to do on the 'Magic Band'. We are simply missing sunspots. Next, the targets must meet motivation, hardware and finally time with respect to work&daily social life (
what?).

  • Do some research and implement changes

  • Find improvements

  • Competition; participate in annual marathon contest UKSMG

  • Work new countries

  • Fun factor; radio is a hobby. Wikipedia says:"Hobbies are practiced for interest and enjoyment". Playing with radio does serve both for me.


Things which worked well


Do some research, implement changes
Hardware; transceiver.
I have spent (too?)much time getting the most out of my 6m transceiver and/or finding a better rig. See my previous blog.
Hardware; antenna.
The main key factor at your station. Get more and bigger antennas up, right? However, measuring environmental noise hat put things into perspective. See my blog of April 12th.
Software; DxBase 2006 Logbook
I run two different logbooks on 6m; one all time logbook for entering any qso which is an all-time new country. Next I have the 2009 logbook which starts from scratch for the annual marathon UKSMG contest.
Software; re-calculating current station design.
VK3UM's Receiving Performance Calculator shows you the overall impact of changing the antenna, adding a pre-amp and/or installing low-loss coax. The total system noise temperature (or equivalent noise figure) shows how much can be really gained, or not. Set Sky noise at 5500 K, representing the average terrestrial noise in a city environment. Terrific software !

Find improvements
The Elecraft K2 +XV50 6m transverter has shown its merits on sensitivity and pure analogue sound quality. Ergonomically it proved not capable, yet.
The Perseus SDR receiver I have for some months now, shows great potential at several disciplines. Best in class performance at band monitoring, doing measurements, finding weak signals, next to being simply a superb DC to 35MHz receiver.
Enjoying 22 years in Hamradio groundbreaking improvements have been: TS850, K2, ORION and the Perseus.
Reading the latest articles of YU1AW on principles of gain/temperature and 30 years development in yagi design, gives you new insights on terrestrial vs local man-made noise as well as relevant interpretation of the current new antenna designs.
I believe there is still room for improvement in my current 50 MHz station set-up.

Competition
Many european 6m operators participate in annual marathon contests. I'm publishing my efforts in the annual table of the UK Six Meter Group. The goal is trying to work as many countries in a single season. All modes are allowed. That is a lot of fun since you can start from scratch every new season. This creates an exciting alternative during these years of low sunspots and ample cross continent dx possibilities. I even run a seperate logbook for the this annual contest marathon. Having already 53 different DXCC countries in Europe makes this a tough task too. At least some 30 countries rely on short-skip propagation which occurs in very few occasions. It does sharpen your tools for hunting the real dx. On one hand this creates band activity, on the other you need to be careful avoiding 'QRM' since you are calling known & easy dx every year again and again. Example; when LY2xx finally becomes available I refrain from calling him immediately in the pile-up on his QRG. There's lots of stations who have never worked an LY ever, and maybe he just has a short window on a path to some other dx. I prefer to work him on a more quiet moment or when the band is just opening.
Achieving serious results requires serious dedication as some countries are available only very occasionally during the season. Sharing your experiences on-air or on the ON4KST webchat is fun.
My result for 2009: 78 worked DXCC countries. That puts me right in the top-ten ;-). Last year I managed 57, but then my QTH was home to a lovely YL (a matter of setting priorities so to speak). My annual record is 82 which happened in 2006. Getting to serious results is a matter of being there at the right time. My station has a single 5 el yagi @12mtrs AGL and output 100W (no PA available). I'm very satisfied with the results.


Mind you; although all modes are allowed in this marathon contest, I refuse any 'digital' modes and prefer only contacts which are truly by human only (own ears, voice and Bencher key).

Work new countries
Triple efforts are put into working a new country. The Es season showed many openings to the Caribic; on several evenings KP4's where available for many hours and could be worked on a rubber duck. New DXCC for me: Americas: VO, 8R, J3, J7, 9Y, from Africa: D4, 6W, TR, TN, 5N, from Asia: 4J, and from Europe: 3A. That makes 12 all time new ones.

Fun factor
Being this a hobby, not an obsession, one has to careful balance time&effort.
I enjoyed the many fine dx qso's made and also love to listen to fellow hams who made it through and share the excitement on the ON4KST chat. On some occasions it was nice to monitor the efforts of other, larger stations who challenge the 'Magic' properties of the 6m band.


Things which worked not so well

Hardware

Super low noise/high gain antennas only show their merits at the right QTH. An experiment using our HB0-dx antenna, seemed crippled due to lack of height and local noise. It was fun
though to set it up, see blog of May 27th.
I also tried an experimental 1.5 wavelength inverted vee antenna at 5mtr AGL. This 50 Ohm antenna has 4 main lobes and served as second antenna. It did not offer anything valuable and was merely deaf in any direction.
The President Madison CB receiver, see my blog of July 11th, served as an experimental Es monitor/warning system. Monitored Es conditions on 27MHz are very different from 50MHz. More important; there is very little activity on CB except for Italy and France.


Band tourists, QRM etc..
Todays bad habit of "I want it all, I want it right now and at no effort" is affecting our ham radio bands for a long time. DX- clusters and Internet has made it worse. There are many hams with bad operating behavior and ditto QRO signals. They drop in upon a cluster spot and act like Monster Trucks, very often not even understanding what is actually going on on frequency and just repeatedly calling with the howling pack. Since the marginal band openings to real dx are such short and fragile, patience and optimal operating practice is most valuable. For everyone.
I have had to let go several potential new ones. Some ops do not understand the mechanism of shifting footprints during small openings and ruin opportunities for their neighbors. A pity, but new opportunities will arrive in the future.
The dx cluster nowadays has become a chatbox. Some digital 'QSO's even require 6 consecutive lines in the cluster to make it happen. Without any shame about the QRM or the bogus contact. Now try to reason them on a webchat.... If they would just care to enter their 'spots'on 50000.0 then it would be possible for us to filter it out.


Plans for 2010 season

TRX Hardware:
I will implement a second receiver setup; the XV50 transverter into a splitter(see blog march 26th), feeding both the K2 and the Perseus. A second smaller 6m yagi to monitor other directions will rise...somewhere...? This and the main antenna will be connected via a cross-switch antenna relay to both main and second transceiver set-up.

Software:
DXBase is aging and not being supported anymore. I want to try something new. I must be perfect to support logging for Top Band as well as VHF (6 & 2m) with plenty analysis options and monitoring alarming systems. Anyone have a good proposition, drop me a message please ?

Antenna:
I will do another local noise measurement, and thentry to raise my antenna a few meters.
Perhaps I will try the all new design from G0KSC.

Remote setup:
We have a farmers house available which is at a very quiet and remote location. Good opportunity for entering a 50 MHz contest.

Competition:
If time allows it; enter the annual marathon from
http://6m.dy.fi/
Perhaps participate in a 6m contest.


So................
Okay that is way enough Magic band talk for now.
The 160m season has already started for crying out loud !
Time to move on.
Thanks and see you next season.