zondag 5 februari 2023

New distance record on 160M : VK3ZL

 After my recently confirmed distance record on 80m with New-Zealand, I just worked  the Australian station VK3ZL... on 160M !
16.633 km with 350W.  I received -10dB and he was -17dB on my inverted L antenna.

As from now on, a DXCC on 160m is just a question of time and patience.  This QSO was due to grayline propagation.

zondag 15 januari 2023

New distance record on 80m : ZL3IO

While preparing my system for an ultimate effort to work TN8K on 80m this night, 

ZL3IO appeared on my FT8.  Just for fun, I called him with 500 W.  

Bingo !  First call = QSO. 

Distance 18.700 km, a new DXCC on 80m and a new WAZ zone on 80m.

To be fair, this is not because of my poor home-made inv-L antenna, but because of his 80m 4-Square.

Anyway, he made my day. 

zaterdag 31 december 2022

DXCC 317 Crozet Island

 This was a hard one.  Finally worked FT8WW on 20m FT8.

I worked him a few days ago, received my report but not the RR73.  I wasn't in the log.  A hard moment.
Afterwards I detected a problem with the yagi.  Again the director failed on 20m.

I can solve this with a retract of all elements, but for sure there is something wrong with my good old Steppir.

Yesterday evening was bingo time.  A well working yagi at 22m, 1500 W (!!) in FT8, and a lucky moment.   And of course, 70 km/h stormy wind.   The first time I pull out the tower at full height, and just on that day so a heavy wind.

This is a hard expedition on FT8.  Many people are sending without listening.  Robots are in the air for hours and hours, sending out stupid reports.  

Yesterday, ON7USB was the absolute LID-champion.  For many hours his robot was sending... in the wrong period.  This caused QRM,  DXcluster frustration and absolutely no result.   

What does an 'amateur' like this think ?  I have to go to work, but I put on my computer, and hopely when I arrive at home this evening FT8WW will be in my log.   Just crazy !

Funny to see other hams trying to confuse his robot and making it believe that there is a valid qso.  All effort just to stop the QRM.

FT8WW also seems to cause problems : in stead of using F/H in WSJT, he uses other software.  First days, he was sending on odd periods, now on even periods.  This makes a hard expedition even harder.

But bravo for all effort he does, as most wanted man of the ham-world.

Next step : put my Optibeam 30m dipole above the yagi and work him in CW

QSLs 2022 printed and sent via buro

 All QSL requests received via Clublog in 2022 are now printed and handled by QDURE.

maandag 5 december 2022

First big steps on 160m

 It isn't easy.  160m looks like a separate world (as it is on the 6m magic band).

I'm still in my experimental era, testing the TX antenna and learning how to work with separate RX antennas.

First positive conclusions :

1. My TX antenna works fine.  

During the WW contest I was able to work 66 countries; E2A (Thailand) and PJ2T (Carribean) found me while I was running CW.

Even better was a good copy (-18 dB) by a VK3 station of my FT8 signal transmitted with 350W and also detected by a ZS station.

2. A windom antenna can be used as a RX antenna.
The pattern looks omnidirectional, I didn't remark any difference between this one and the inverted L, although signals arrived more qrm-less.  Only one station felt into the windom that I couldn't copy on the vertical : WA7NB, Arizona, arrived with a nice signal and passed away few minutes later.

This is what is mentioned in literature : sometimes DX stations arrive unexpected on a low dipole antenna.

3. A BOG works !  I have installed a Beverage On Ground, 60m long, and it works.  But, I need the preamplifier of the transceiver.  It has also directivity and a nil on the backside.  Installed SW to NE, RA stations entered very well, but EA was practically unhearable.

On FT8 I did a test listening to callers to a 5R DX station.  A my inverted L 5 callers were detected.  On the BOG 33 (!) callers appeared on the screen.  

First negative conclusions :

1. I need more directional receive capacity.  No only to hear better the DX, but to eliminate European QRM of callers who don't listen.  This is really a problem.  Due to this, I missed a lot of Carribean multipliers.  

I can install 4 BOGs on my own property, and I'll do someday because it is almost invisible an easy to do, but...

2. I'm not sure that a BOG is able to perform well on long-distance DX.  Imo a normal beverage will do this job much better.

For that reason I ordered the necessary beverage stuff with preamplifier (DC over coax),  at the antenna.  Only to install in case of an expedition (read : Bouvet)

Listening is not cheap at all.  Today, 100m of Ecoflex-10, the coax I normally use for all antennas, costs 555 €.  For RX purposes on 160/80m I prefer RG213 for price reasons...

maandag 28 november 2022

Creation of an inverted L antenna on 160m

Finally I am able to construct an almost perfect inverted L antenna for 160m, taking into account my preferences :

1. Have resonance nearto the FT8 frequency (1840 Khz)

2. Keep the vertical part at about 15m in order to survive winter storms.  I don't want to pull up and down the tower depending the weather forecast

3. Foresee around 30 radials of 1/8 wavelength

This is the final result : 

and in real the base looks like this :

But before the final result, there are some intermediate - sometimes frustrating - steps.

For all beginners, this is a quick manual :-)

Step 1 :  Cut the wire to the preferred length via the trial and error method.  

Because this is an inverted L, it is quite easy to shorten the horizontal part of the wire.

Once this is ok, the result seems very fine.  Resistance close to 50 Ohm, SWR 1,7, clear dip nearto the FT8 freq.

But ! The efficiency of the antenna is very low when you use it like this.  Without radials, ground losses are far too high.  In my starting years, I would have stopped at this point,  focussing on good SWR and not too much labour.

Step 2 : Add radials

There are many articles on the internet about the installation of radials on vertical antennas.  It seems that up to 24 radials, you can place 1/8 lamba radials in stead of 1/4.   I have 32 x 21m radials.  The only reason is that I had the radials ready in the box, used for my 80m vertical.

As predicable, but not making happy, the resistance of the antenna gets down to about 15 Ohm.  SWR raising up to 3.5, too high to connect to a linear amplifier.

Step 3 : Add a coil between to hot side and ground.  

This is also known as the hairpin method.  I used a coil from my Butternut vertical.  It's also a bit trial and error, the result is not perfect at all, but it lowers the SWR to 3.  

The resistance stays low, creating possible (too) high currents.   It this point it must be possible to use the antenna with a tuner inside the shack.  Remark also the BALun used to avoid unwanted radiation on the coax.

But this is not the correct use.  There is a better solution

Step 4 : add a 1:2 UNUN

Final step : I contacted Hugo, ON7FU, a real specialist in transformers.  He was capable to make a UNUN within 1 day.  Fantastic job, I could use it during the CQ WW CW contest.

Replacing the Balun by the Unun, resistance goes up to 49,5 Ohm !!  :-)   SWR 1,07, no tuner needed, no EMC risk and high power available at the antenna.

The dip is on 1831 Khz, nearto 1840 Khz for FT8 and perfectly usuable for running in the CW contest.  

Most important (see my blog about the windom antenna on 160m, with changing SWR depending on the weather)  : This antenna stays tuned.  No changes in impedance due to rain or other influences.

But the proof of the pudding in is the eating...


New objective for the coming years : 160m DXCC

Magic Band DXCC goal achieved !  One year earlier as expected.

So time for my ultimate HF challenge : DXCC on Topband.

During the last years, I collected some hardware to play on topband, but all of this stayed the boxes.  

Since this weekend I'm migrated to only one band : 160m.   
Steppir and 30m vertical stay operational in case of a new ATNO DXCC, but are not connected to the shack.

On my first coaxial hardline I've an inverted L, the second hardline provides connection to a remote switch with the possibility to connect up to 4 receive antennas.

As always my 2 basic principles are implemented : 

1. Keep it as simple as possible.  No complex array solutions, beverages only if really needed.

2.  Follow the Pareto principle.  20% effort to achieve 80% result.  Therefore I don't want to work 300 countries,  I just want 100 countries, no WAZ, no WAS even not a WAC if too difficult.

At this time I've 63 confirmed countries on topband.