vrijdag 30 november 2018

CQWWDX SoSb-A 160m

My first single band contest on 160m.  Expectations were not easy to define and not too high. 
Until now, I only worked 50 DXCC, most of them with an inverted L antenna and with high qrm.
Goal : if possible 500 Q with at least 50 DXCC (and hope on some new ones) and without technical problems.

Using the windom antenna I hoped to perform better on receiving but I was a bit afraid of the high angle of the antenna, which is only 15m above ground.
Preparations as usual, last minute.  I measured the antenna on Wednesday and the resonance point was at 1740 Khz.  100Khz to low, so the antenna was too long.  I calculated the length and fold back the both endings, keeping the windom 1/3 versus 2/3 factor in mind.
Now the dip was on 1790 Khz, not what I calculated, but I had not the time to do more fixing.  I forgot to torsion the wire.  Just fold it back with some tape.  I found out that the swr was swinging between 1.4 and 2 on 1835 Khz.
I decided to start the contest with the OMpower ampli, because this one can suffer more reflected power.  Goal was to use 1000 W, if possible 1300 W.
After a few seconds, the first failure occurred, too much reflected power.  I found no other solution than to continue with 500W.   At 4h UTC I stopped after 200 Q’s, all S&P, because I needed some sleep to perform well on my streetrunning competition on Saterday afternoon.
On Saterday morning, the weather was very rainy.  I measured my swr and this time resonance occurred on 2200 Khz !!! 
I suspect ground increased capacity as the root cause of this move.  Back into the garden, undo the folding on both sides and measure again.   SWR stayed too high on the contest frequencies.
Plan B : place my good old manual MFJ tuner in between antenna and ampli and run with the Acom1000.  I achieved 750W without sparks.  This was a good choice.  I could make my 500Q  within a few hours, and achieved 64 countries.  On Sunday morning I stopped the contest, to have some family time.

Conclusions : 
-          There is no benefit on 160m using FT8 200W for new countries.  With 750 W in CW I can make QSO with the Carribean area, strictly needed for DXCC.

-          The evolution in assisted mode is very much expanded by adding skimming features into the cluster.  I suspect some USA stations could “hear” me thanks to this information.

-          On receiving side, my antenna performed very well.  Much less noise compared to the vertical

-          Weakest point was Asia and Middle East.  On 80m, working Carribean means also working JA and YB.  On 160m this was not the case.

-          The windom antenna @15m performs very well and is stable on all bands, except for 160m.  Here the ground behavior has a huge impact on the resonance point.

dinsdag 31 juli 2018

New 160m windom antenna on the air

No more yagis, not even a dipole, but a 160m windom antenna is now my main (and only) antenna.

With a total distance of 82m, the longest leg is 57m, this is a monster.  
Everything seems out of proportion when taking a picture of this antenna. 
The height of the longest leg is at least 15m with a sloping ending in the far end of the garden.

Thanks to the ON5ZO construction I'm able to put it so high on a (relatively) simple way. 

More important for me, this construction can be storm and lightning protected within a few minutes.
Because I can only be active during weekends in wintertime, I can put it up on Friday and lay it down on Sunday without too much effort.

160 m windom antenna - 25 m going to the roof of the home - 57 m from the tower to the far end of the garden with in between the on5zo construction to keep it high and divide the forces of the wire.

In order to divide the forces I use a vertical wire to fix the antenna to the 15m high intermediate construction (made for a 80m vertical).  This exists of the old KT34XA alu boom and a 5 m spiderbeam on top of it.  From the construction the antenna wire goes down and is connected to the end of the garden with a second wire.

The connecting part is on the tower where I use the existing basic part of the Optibeam 30m dipole.  Both wires coming from the 4:1 balun are first connected to this tube (protected by to fiber tubes to avoid electrical connection).   This prevents that when raising the tower, a wire tough the alu part and give problems.

It was also a method to quickly switch back to the Optibeam in case of problems with the wire antenna.

Measurements are more than satisfying.
In all CW parts, SWR on 80m/40m/20m/10m is lower than 1,5:1, mostly 1,2:1.  Only on 160m I measure 2,2:1 (resonance occurs at 1740 Khz).

SWR on 30m/15m is slightly higher as expected.
SWR on FT8 frequencies are also around 1,5:1 (160m 3:1).

A first test on 40m in the afternoon gives super results with BV, many YB's, and reception reports in VK

To be continued...

zondag 29 juli 2018

How is ON4CCP's 1 Watt project doing ?

Fine !

243 QSO's made with the 30m dipole and the G5RV. 
A total of 314.000 km worked.

It's a hard job, only 1 Watt isn't really much power to use in this solar cycle dip.
Most of the time other stations come to call CQ on my frequency.

Sometimes there is a suprise, like the 9A who came back on 50Mhz (using the harmonics on 30m dipole).  Or the K-station on 18 Mhz, more than 6500 km away.

Looking forward what would and could be possible on 10 meter with a 5 element yagi and a solar maximum.

woensdag 25 juli 2018

First FT8 awards arrived

2018 will be a fantastic year in my ham carreer. 

With >3000 QSO until now, 90% in digital mode and all done with a single element or wire antenna, it's a new world that has been opened.

Last days I made some hundreds of QSO on 18 Mhz with the G5RV.  With a height of at least 12m on every part of the legs and an angle of 180° between, the antenna delivers optimal results.
The predicted 4 lobes on this frequency are detectable in the log.  Ie. USA, SA, JA and Middle East. 
Almost no Carribean stations worked.

Everything is now ready to change this wire by the new 160m Windom antenna.  
Just waiting on a day with a temperature  <30°C.

The first FT8 awards arrived via mail (using Ultimate AAC combined with the FT8DMC club.  All handling is automatic based on a standard ADIF log).

Worked All Continents on 80m, Worked All Japan on 30m and 500 grids worldwide.

Total cost : 0 €, delivery time : 12 hours thanks to a great job of award manager A92AA. 
DXCC has a problem if this nice way of working by others continues that way.

maandag 11 juni 2018

New project : ON4CCP on the air with.... 1 Watt

After a very successful fieldday -- some need >1 week to send a log to the UBA, so we don't know at this moment if we  won the contest-- , it's time for new business.

I activated my FT817 QRP station on FT8, with only 1 Watt of outgoing power.

Goal is to make 1000 QSO with ON4CCP.
Everybody will receive a qsl, logs also available on Eqsl and LOTW.

It's almost incredible that such a small signals travel allover the world.

With my optibeam 1-30m dipole, I was even heard in VK.

Next time I hope to make a full 2 way contact with VK.

After only one weekend, I was able to make 105 QSO's, good for a total distance of 105.000 km.

I never used such a low power level.

Some QSO's were even made on 6 meter (using the 5th harmonic resonance point on my 10Mhz antenna).

Not everything runs like wanted. 
This weekend a problem occured on my Acom1000. 
I suspect a issue with the relay inside the ampli.  A "hot switching error", even with 7W of drive appears on the display.   To be investigated the next weeks.

I also read some comments on FT8 : link

Oh boy, what a high level of literature...

No changes , no evolution allowed; let's climb into our trees in the jungle, together with Adam & Eve.   With such an attitude, Darwin should have been workless.

Strange that those pessimistic guys use internet to complain...

woensdag 23 mei 2018

DX analysis of FT8 contacts

It's one of my interests to analyse why and how contacts can made possible on a specified band.

This weekend I worked a YC6 at 19h UTC.  It was before sunset on my side and before sunrise in Indonesia.  So this contact is a surprise for me.  We exchanged -16dBm and -15dBm.

At 22h UTC I worked another YB.  This time we were both in the twilight zone.  In accordance with the expectations on 80m.  We exchanged -24dBm and -16dBm.

Same graph for the USA contacts.  Although the West coast was in also in the twilight zone around 3h UTC, nobody came back to my call.  I suspect the G5RV in this case.  To be continued