zondag 7 juni 2015

CQ WW WPX CW contest 2015 with an indoor 15" Cylinder dipole

15" Indoor Cylinder dipole PA1B
I had great fun in 56 QSO's in CW with S&P, with 20 DXCC countries with an indoor 15" cylinder dipole. The antenna consist of two 500 ml energy drink cans and a coil of 80 mm with 8 turns.
By making QSO's in a major contest, I could discover the properties of this very short antenna.
On Saturday I worked with the antenna in  the shack, with the antenna 4 meters above the ground. On Sunday morning I placed the antenna in the attic, on a height on 7 meters above the ground.

On Saturday I started on 14 MHz. Between QSO #3 and #4 we went to a fair. After working 6 stations all on 14 MHz, I went to 21 MHz.
The 15 meter band was open, so I made all QSO's on this band from 12 UTC until 19 UTC. From time to time I went back to 14 MHz, but with NO success.  After 19 UTC I could make just one QSO on 20 mtrs. After this QSO an other 16 QSO's were made on 15 m. After 19 UTC the signal were stronger so I could reduce my power. Then I  could make QRPp QSO's with 720 mW, 360 mW and even one with 72 mW. When the S-meter goes up my power goes down.

On Sunday morning I had time until 10 UTC. The first QSO was made with the island of Man on 7 MHz. To work on 7 MHz I tune the SWR for 1:1. After breakfast I divided to move the antenna to the attic, just to test whether I could make more QSO's on 14 MHz.The test is not conclusive because I made the same number of QSO's at the same time as on Saturday.
Between 10 and 18 UTC we visited two birthdays. after 18 UTC I made a few QSO's.

Does it work?
The antenna definitely works.
Because I had limited time on Sunday afternoon, I can not tell whether the antenna works better on the attic on 14 MHz. But I can tell you that it works.
When did you make QRP QSO's with 20 DXCC counties on a indoor antenna?

CQ WPX CW 2015 with an indoor 15" Cylinder dipole PA1B
Worked DXCC's in the CQ WPX CW 2015 with an indoor 15" Cylinder dipole PA1B

7 opmerkingen:

  1. Zeker niet slecht Bert. QRP en dan ook nog met frisdrank blikjes. Wie had dit gedacht. Leuke analyse. 73, Bas

    1. Hallo Bas en Tjeerd, ik ben geinspireerd door Mike, VE3WDM en John, N8ZYA met hun binnenshuis antennes. De antenne werkt net zo goed als ik verwacht had. 73, Bert

  2. Hi Bert, thanks for your comments on my blog and congrats on the "can" antenna.
    Prop has been strange lately - my friend Mikel EA2CW reported 20m being very quiet even with 100W during the contest. I worked Nicaragua & Puerto Rico on 17m & 30m last Friday night - 11z - with 5W. 20m has been open until quite late to EU. 30m has been open too for DX.

    73 Angel

    1. Hello Angel, I am very happy to read the propagation observations on 14 MHz on your Blog.
      I suspect that it is a matter of propagation that I could not make any QSO's on 14 MHz on Saturday afternoon.
      I am very happy that the Cylinder dipole can be used as a multi-band antenna. 73, Bert

  3. Hello Bert, wery interesting this "magic antenna" i guess it is important how the coil is placed. Just nu håller vi på med renovering av klubbens (SK5DB) hela antennsystem, but i will try this antenna when i get some time for it. (Men jag kommer att pröva den här antennen så for jag får tid.) 8-) Tack för dina komments på min sida. Även på hemsidan sm5mek.se går det att kommentera i "blog". 72 de Jenny SM5MEK

    1. Hello Jenny, thank you for your nice comment. The cylinder dipole works very good. Themagic of the cylinder dipole is in its cylinders. Consider the cylinders as a very, very THICK wire. The capacity of the cylinder can be as large as a few hundred pF. Short wires have a few pF's. The large capacity of the cans together with the coil resonates at HF. ;-) But the cylinder dipole can be used at a higher or lower frequency then the resonance frequency, when using a tuner, to get a good SWR. With two 500 ml cans the coil of 80 mm should have about 10 turn to get on 14 MHz. Just try. 73, Bert