End fed met lineair loading

Eindgevoede draad
Toen mijn inverted V in mei 2015 zodanig beschadigd was door de wind, ben ik eerst overgestapt op de Cilinder dippool, waarmee ik van 2015 t.e.m. 2016 gewerkt heb. Maar begin 2017 wilde ik weer een antenne buiten ophangen.
Net voor de PACC (2017) heb ik daarom gekozen voor een End fed.

Ik had op vakantie veel ervaring opgedaan met de endfed, die gevoed wordt via een 300 ohm lintlijn met een lengte van 4,80 meter. De endfed in in combinatie met mijn licht gewicht vakantie tuner heeft mijn veel leuke vakantie QSO's opgeleverd.
Zie: https://a29.veron.nl/hams/pa1b/qrp-holiday-transmatch/

Draad
Ik had een lang stuk draad van meer dan 20 meter, dat ik niet door wilde doorknippen. Dus heb ik dat gewoon in zijn geheel opgehangen. Om in de achtertuin te passen moest ik de draad terugvouwen. Omdat ik 12 meter over had heb ik besloten om twee keer 6 meter terug te vouwen. Hi.

Linear loading
Lineair loading is een fraaie term om het gedeeltelijk terug vouwen van een (lange) draad aan te geven. Ik heb de term ergens opgevangen, bij iemand die op deze manier zijn verticale antenne verkortte, zonder gebruik te maken van een spoel ergens in de draad. Door het gedeeltelijk terugvouwen van de draad, kan ik een grotere lengte kwijt in mijn tuin van beperkte omvang.

Staande golf
Op een “zendende” draad staat een staande golf. Op het eindpunt is de stroom nul. En verder van het eind wordt de stroom in de draad groter. De stroom in het teruggevouwen deel loopt tegengesteld aan de stroom in de draad, waarlangs hij teruggevouwen is. Over de lengte het teruggevouwen deel heffen de magnetische velden elkaar gedeeltelijk op, waardoor het teruggevouwen deel vrijwel niet straalt. Het HF vermogen wordt door de rest van de antenne uitgestraald.

300 Ohm lintlijn
In huis wordt de draad gevoed via een 300 ohm lintlijn. Dit kun je ook weer opvatten als lineair loading. Het lint brengt het HF signaal buiten de shack zonder zelf veel te stalen. De stroom in de beide aders van het lint lopen tegengesteld, waardoor de lintlijn vrijwel niet straalt.
Het lint werkt als een impedantie transformator. De tweede draad van de lintlijn werkt als een counter poise. (Tegenwicht) Het antenne systeem heeft daardoor geen aardesysteem nodig.
Als ik op 7 MHz werk schakel ik nog een extra stuk lintlijn van twee meter lengte tussen tuner en het lint naar de zolder. Hierdoor is de antenne dan wel (of beter) aan te passen.

Windkracht 12
Mijn inverted V die ik eerst gebruikte was windgevoelig. Die moest ik meestal één maal per jaar in zijn geheel naar binnen halen, om het lint of de draden te vernieuwen. De eind gevoede draad hangt al een jaar of vier, waarin ik heel af en toe het touwtje tussen de antenne en het schuur dak moet vervangen, omdat het vergaan is.  

Windkracht 12 is wat overdreven, maar deze end fed is veel minder windgevoelig dan mijn inverted V. Hi.

CQ WW WPX CW contest 2017

Last year I used the cylinder dipole with two Monster cans for 21 MHz.
I am very pleased with the excellent write up on the PA1B cylinder dipole
in the results of the 2016 CQWW WPX CQ contest of last year.
See My Blog post on the article.

This year I used an end fed antenna for 14 MHz, that is sloping down to the east.
In total I made 91 QSO's. I did not use a fixed power.
When the signals go up, I reduce my power.
The power that I used, varied from 3.6 watts down to 3.6 milliwatt.
All QSO's were made with the lowest possible power with search and pounce. S&P.

I started on Saturday on 14 MHz and when I stopped there were 40 QSO's in the Log.
On Sunday  morning I first made 11 QSO's on 7 MHz.
Then I went to 14 MHz to make about 40 more QSO's.

CQ WW WPX CW 2017 - Number of QSO's per power category - PA1B

QRPp   < 1 W
As a milliwatt enthusiast the emphasis of my activities lays on the use of QRPp. On 14 MHz I made 39 QSO's with a power of 360 mW and 22 QSO's with 800 mW. When the signals go up, I reduce further below 100 mW. The table shows 18 QSO's with less than 100 mW, with 2 QSO's with a power of 3.6 milliwatt.

Very low power QSO's on 14 MHz
On Saturday I started after 16:00 UTC. In the first QSO I probably was too eager to use low power, that I am not sure whether the QSO is valid. After 18:00 UTC till 20:00 UTC the signals peaked, with  6 QSO's with 36 mW and two QSO's with 3.6 milliwatt.

S-Meter reading
An important indicator for the power that I can use, is the S-meter. The signals in the  two QSO's with 3.6 milliwatt were ear splitting. To get an indication of the signal strength,  I switched in the attenuator of 20 dB. The S-meter still gave a value of S⁺. This means that the signal strength is  S⁺ plus 20 dB. Hi.

UBA DX CW 2017

I was looking forward to participate in the UBA DX CW contest with QRPp. This is a very nice contest with a lot of activity. I found out that my End fed antenna is working fine. This time I also made a few QSO's on 7 MHz. I discovered that I had to use a longer twin lead on 7 MHz than I use on 14 MHz. I made most QSO's on 14 MHz using QRPp. Click to see my End Fed with a twin lead feeder.

I came back home late, so I made 1 QSO on 14 MHz and 3 QSO's on 7 MHz on Saturday.
On Sunday I made 23 QSO's with 360 mW and 7 QSO with 800 mW to 3.6 Watt.

UBA DX CW contest 2017 - PA1B
Numbers in red are more than 1000 Miles per Watt

I am very pleased that I could make that many more than 1000 Miles/Watt QSO's.
I ran the FT-817 without the attenuator.
The lowest power of my FT-817 is 360 mW, after a serious mismatch.
But as you can see, this low power is still working fine most of the time. Hi.

20 m UBA DX CW contest 2017 - PA1B
Numbers in red are more than 1000 Miles per Watt

All QSO's were made with Search & Pounce (S&P).
I only increase my power when I am sure that my low power signal is not heard.

40m UBA DX CW contest 2017 - PA1B

Using low power, is absolutely not that difficult and is great fun.

ARRL int DX CW 2017

I was hoping to make QRPp QSO's in the ARRL international DX CW contest 2017. I did not make many QSO's, because I had very limited time on both days. But I did enjoy the contest very much.
A week ago I made an End fed antenna to work in the PACC. The antenna is sloping down to the east, so I was curious how the End fed would do to the west. I am not disappointed.

Saturday
Because I was away for most of the day, I started late on Saturday on 14 MHz.
In the first 3 QSO's I had to use 3.6 W and 1.8 W. After that I could reduce to 800 mW.
When the band closed on Saturday evening, I had made 11 QSO's all with Search and Pounce (S&P). The signal of K1ZZ was very strong, so I reduced to 360 mW before answering his CQ.
The response was immediately correct.

Sunday

When I started on Sunday I could hear European stations. On 14 MHz I could only hear stations that I had worked before on Saturday, so I went to 21 MHz. On this band I could work 6 stations all with just 800 mW, as you can see in the table below. I could work with W3LPL with 360 mW. His response was also immediately correct. hi.

ARRL int DX CW contest 2017 PA1B
Numbers in red are "more than 1000 miles per watt QSO's"

599 001      001?

Working with QRP and QRPp is great fun.
In the ARRL DX CW contest the DX stations like myself give their power in the report.
When I reduce to less than 1 watt, I will give the report 599 001.
This report can create some confusion. When I use 3.6 W I will give 599 004.
I will give 599 001, when I use a power of 800 mW, but also with 360 mW.

One operator was quiet for one full second after receiving my 599 001, before he realized that my power was about 1 W.  Hi.

Excellent ears

When I met K5ZD and N1TA, their  signals were not that strong and the QRM was increasing. I was really surprised that they could hear my 800 mW at all. But we could complete the QSO with no trouble at all. FB. Probably they had less QRM than that I had.

End fed

I am very pleased with my End fed. It works fine to the east and to the west.

PACC 2017

In the PACC 2017 I made 51 QSO's. In most QSO's I used 800 mW by giving CQ or by using S&P.  The 20 m was good for most of the QSO's.

Friday before the PACC I made an End fed antenna with about 20 meters of wire. Just as my holiday antenna's the wire is feeded via a twin lead that acts as counter pose and impedance transformer. I applied linear loading to make the wire fit in my garden. This antenna is a great success.

Inside Europe I could make QSO's with QRPp running with just 800 mW. With 800 mW all QSO's over a distance of more than 800 miles (1280 km) are good for more than  1000 miles per watt. After the contest I counted 38 QSO's with more than 1000 miles per watt in my log.

The power of 800 mW was not enough in every QSO. I had to increase my power to 3.6 W, to work K6ND and P3YA and a few other stations.

The antenna is a great success.  I could run with QRPp with a power of 800 mW.

As a milliwatt enthusiast I often use the lowest possible power from QSO to QSO in other contests. Then I use Search and Pounce. (S&P) But when I give CQ, it is more difficult to copy the call than when I use Search and Pounce. Most of the time I must hear the call twice to copy the call. 

I enjoyed meeting operators that were patient. FB.

Auxiliary antenna for the PACC

At first I did not think about contesting at all, because my inverted V is damaged. In the summer I had great fun with my cylinder dipole with Monster cans on 15 m with a power of 3 watts.

PACC
When I was on the Veron club meeting, I heard that the avid contesters were preparing for our annual contest from the Netherlands, the PACC. So I also got inspired to participate.
But with what kind of antenna?

Antenna?
I did not want to use the indoor cylinder dipole with Monster cans. Because of it's low height of 4 meter above ground level, a power of 3 or 4 W would be needed. And with winter propagation, it is not even sure, whether the 15 m band will be  open.
But most of all I wanted to participate with QRPp on 20 m.

End fed wire
So I begun thinking about an outdoor antenna. With more height I can use less power. To limit the activities on the roof, I came up with an end fed. I had a wire that was too long. But I decided to put it up and see. So on Friday afternoon before the PACC I ended up with this end fed.

End fed with twin lead feeder. PA1B

To get the power into the wire, without radiation in the shack, I use 300 ohm twin lead. The  twin lead also acts as an impedance transformer. I always use a tuner with my antennas. So whatever the impedance at the end of the wire may be, as long I can adjust the SWR to 1:1 it's fine with me. The twin lead has to be long enough to tune. A twin lead of 4 meters works fine on 14 MHz.

I use this type of feeding by twin lead for all my end fed holiday antenna's since 2001.

First place in the YO DX HF contest 2013 for CS8/PA1B

Today I received a beautiful Award of the YO DX HF contest.
Last year I partcipated while on holiday on the beautiful island of Saõ Miguel on the Azores.

During the contest I used an end fed wire on the roof of the hotel.
In the contest I used my FT-817 with 2.5 watts or less and a homemade light weight keyer.

The envelop from Romenia arrived in the rain.
When my wife entered the room with the wet envelop, she said:
"I hope all is OK".
I immediately recognized the envelop of the YO DX contest.
Despite the rain the Award is in good condition, because it is plasticized.

My thank goes to Ovidiu YO2DFA, the contest manager of the
YO DX HF contest.

CS8/PA1B   First place in YO DX HF - Azores - Single OP - 14 MHz - Mix 

CS8/PA1B First day of operation

Light weight keyer in the foreground  

It's great to take a station with you on holiday.
But when I am on holiday, I am on holiday and not on a DX expedition.
In general I make a few QSO's each day and a modest number of QSO's in a contest in the weekend.

On holiday I made a total of 72 QSO. On the first day I made 11 QSO's. On other days  I made a few QSO's each day. On the last days 47 QSO's were made in the YODX HF contest.


First day as CS8/PA1B
The first day of operation I made 6 QSO's in the RDA contest.
After I returned home after the holiday, I discovered that, because of the low power and the distance to UA2 and UA3, all QSO's in the RDA contest a made with more than 1000 Miles per Watt. hi
The first day it is always exciting, because I am curious which countries and continents can be reached.
After making some QSO in the RDA contest I made some QSO's outside of the contest. See table at the right.

Most of the time I work with Search and Pounce.

The signal of PT7FLA was very strong, so I used just 360 mW.

2 Way QRP QSO with N5EEI
I never hunt for other QRP stations, so when I gave CQ with 2.7 watts,  I was amazed to meet another QRP station.
Dave N5EEI reported that he worked with 5 watts into a dipole 10m up. 

I was lucky to use just 1.8 watts in most QSO's on the first days, since most of the QSO's resulted in a more than 1000 Miles per Watt QSO.

Antenna
The antenna was placed  just before the RDA contest.
I placed the antenna on the roof, together with João of the technical service to get access to the roof.
The antenna wire with a lenght of of 20 meters, ran from the balcony up to the roof and then to a point a few meters above the roof. The antenna did a great job.

The antenna at CS8/PA1B

After we booked our holiday to hotel Royal Garden in Porto Delgada on the island Saõ Miguel, I hesitated wheter I should take the portable station with me.
But I am glad, that I did bring along my FT-817 on the 12V - 4Ah battery.

Activity
In the months before the holiday, I figured out that the YODX HF contest fall into our holiday. This is a very fine contest in which everyone works everyone.
If I could use a 20 m long wire, as I did in 2011 on holiday on Terceira, (click to read the article)
I would have great fun in the YO DX contest.
So I decided to take the FT-817 with me.
But at that time I was not sure, whether it would be a success.

The problems:
My FT-817 has a maximum power of 2.7 watts.
On holiday I operate from a 12V-4Ah battery, so the power will be even lower.
The extra weight of the heavy FT-817 and the battery.
Further I did not know, whether I could put up an antenna.
But most of all, if I could only use an antenna in the central garden, it was possible
that all signals from the antenna could be blocked completely.
The XYL does'nt want to be visible while helping lowering a wire from the balcony.

Antenna
At first I tried to make a end-fed sloper from the balcony into the garden, but in the proces of
lowering the wire, the wire got stuck and my wife refused to help any further. End of part one.
When I mentioned, a few days later, that the roof would be the best place for an antenna, my
wife said: "ask the reception".
The lady of the reception (Graça) was very supportive.
I showed her the licence with the authorization to use a portable station from a hotel.
She first contacted the manager and then the men of the technical service to get the access to the roof.
So later that day, the 20 meter wire was "flying above the roof". WOW.
Thanks to Joaõ, for us putting the antenna up together and to Miguel to remove the antenna.

Feeding the antenna
I don't like antennas with a difficult earth system.
So on holiday I use a end fed antenna which is fed like a Zepp via a 300 oms ribbon.
For more info see the article on my site: The QRP holiday transmatch.  (Click)
The 300 ohm ribbon from the room to the wire has a lenght of 4.8 meters.
The ribbon transforms the high impedance of the feeding point of the wire into
a lower impedance at the transmatch, which is connected to the transmitter.

Starting on the 17th of August until the 25th of August a total of 72 QSO's was made.
So the antenna was working very well.