zondag 12 maart 2017

G4EFE WSPR with 5 mW on 40 m

Martin G4EFE is an enthusiast milliwatt WSPRer.
I curiously follow the WSPR adventures of Martin in which he uses very low power.
Here I show new analysis of the spots that Martin made with a power of 5 milliwatt on 40 m with a full-size 40 m square loop.

The table shows the number of spots over a three day period, from day to day and hour to hour.
From the used power of 5 mW (in all spots) and the SNR, I calculated the lowest possible power.
A spot with a SNR of -28 dB is a "solid copy" in WSPR. So when, for instance, the SNR is -18 dB, the signal is 10 dB stronger and could have been 10 dB lower and still give a solid copy, with a SNR of -28 dB.
The better the SNR, the stronger the signal and the
lower the calculated lowest possible power will be.

In the spots that were received by F6EHP, you can see the development of the propagation from hour  to hour. You can see that the signal peaks at 9 UTC at 3-2-2017. The strongest spot could be made with a power of 0.1 milliwatt. This is also the strongest spot in this table.

Martin uses his IC703 and an attenuator to make a power of 5 milliwatt. His antenna is a full-size 40 m square loop. As I saw on WSPRnet.

zaterdag 11 maart 2017

PA1B Cilinder dipool in de BQC Nieuwsbrief

De cilinder dipool is een interessante antenne, die zelfs binnenshuis gebruikt kan worden. Vooral met de cilinder dipoool met Monster blikken, die bij uitstek geschik is voor 21 MHz, heb ik al veel QSO's gemaakt. 
Ik heb vandaag enthousiaste reacties gehad van BQC leden, op het artikel over de cilinder dipool in Nieuwsbrief 161 van de BQC, tijdens het bezoek aan de Vlooienmarkt in Rosmalen.

In het artikel over de cilinder dipool met Monster blikken wordt verteld, dat de capaciteit tussen de blikjes overgeveer 6 pF is en deze capaciteit een essentiële rol speelt, bij de werking van de cilinder dipool.
Er wordt uitgelegd dat de cilinder dipool zich gedraagd als een parallelkring, de blikjes niet van blik zijn, maar van aluminium en welke voordelen dit biedt.
Verder wordt uitgelegd dat de cilinder dipool via een 300 ohm lintlijn gevoed wordt en daavoor een symmetrische tuner gebruikt wordt.
Veel leesplezier met de BQC Nieuwsbrief.

Cilinder dipool met Monster blikkken - PA1B

woensdag 8 maart 2017

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 not that difficult and is great fun.

woensdag 1 maart 2017

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.

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.

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.