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.

Saturday
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.

Sunday
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

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    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

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  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

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    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

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  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

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    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

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