DX’pedition: first test of deployable 200 metre longwire antenna by Oxford Shortwave Log

A view looking toward  Oxford Shortwave Log DX’pedition territory; a wood in rural Oxfordshire

Regular viewers of my youtube channel will know that I spend much of my shortwave listening time out in an Oxfordshire wood where QRM is negligable and Tropical Band stations can be heard with, at times, unprecidented signal-to-noise. Regular viewers will also be aware that I enjoy experimenting with different antenna set-ups, particularly pushing the boundaries with longwires coupled to portables. Having applied my rather modest practical skills, I constructed a 200 metre deployable 200 metre longwire antenna and finally got around to testing it, with my Elad FDM DUO and Sony ICF-2001D. There are a number of reception videos still to be uploaded to the Oxford Shortwave Log youtube channel, howvever, the immediate information and entertainment of SWLing Post readers, I have included two here. 🙂

The first is the more commonly heard Emisoras Pio XII from Boliva on 5952.5 kHz using the Sony and the second, the much more rarely reported Radio Chaski from Peru on 5979.9 kHz using the Elad. Both reception videos were very encouraging. In fact, I would go so far as to say they demonstrated excellent reception witihin the framework of their respective contexts. Emisoras Pio XII was almost booming with unprecidented signal strength and clarity, whilst Radio Chaski was heard with discernible audio. Neither station had been received as well at my QTH or the woods, previously.

Direct link to reception video of Emisoras Pio XII from Boliva on 5952.5 kHz

Direct link to reception video of Radio Chaski from Peru on 5979.9 kHz

I hope this gives other DXers ‘food for thought’ with regard to experimenting with antennas and perhaps more importantly, making significant improvements to SNR by removing themselves from the ubiquitous blanket of QRM generated by all of those devices at home that are intrinsic to modern life. Thanks for watching. 73.

Clint Gouveia is the author of this post and a regular contributor to the SWLing Post. Clint actively publishes videos of his shortwave radio excursions on his YouTube channel: Oxford Shortwave Log. Clint is based in Oxfordshire, England.

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10 thoughts on “DX’pedition: first test of deployable 200 metre longwire antenna by Oxford Shortwave Log

  1. DanH

    Nothing short of astounding. Hedgerows could provide a means of support. I’m pondering what long barbed wire fences found here in the western US could offer as “found” receiving antennas (hot electric fences excluded).

    Reply
    1. Clint Gouveia Post author

      I’ve read of metal fences being used as huge antennas. There’s a lot of what I call ‘voodo’ engineering with antennas and it’s possible to go to huge amounts of effort for effectively diminishing returns. There are a few rules of physics that apply of course, but ultimately it’s more fun to simply experiment. Good luck!

      Reply
  2. Tudor Vedeanu

    Baluns have little to no effect for receivers. The signal loss due to impedance mismatching is easily compensated by the gain of the receiver. However a balun is useful for one thing: it protects the input circuitry of the radio against static electricity.

    I used to use a 200m antenna a few years ago. It worked pretty well especially for long wave but it also captured a lot of atmospheric noise (I’m located near mountains) so on SW often the S/N ratio wasn’t too great.

    Reply
    1. Emily Taylor

      Yeah I tried grounds and baluns as well and not to much different except for longwave and the bottomhalf of mediumwave because the antenna was too short proportionally. Same goes for PA0RDT mini whip.

      Reply
    2. Clint Gouveia Post author

      I should have been more specific; mine and the original purpose of the Beverage design I am using is mainly for LW /MW DX where baluns can have more of a positive effect with impedance matching. Having said that, no apsect of the design is ‘critical’, including the termination resistance. You are absolutely right that they protect from static discharge. 73

      Reply
  3. Clint Gouveia

    This was just a quick test, so simply a coaxial feed in. I tried a nooelec 9:1 balun which made no difference to either receiver. I am currently building my own baluns, suitable for 75 and 50 ohm input in weather-proof enclosures. These will allow an earth from the antenna side and an earth to the lead-in coaxial shielding. The wire is deployed from a spool manually about 5 feet above ground. The final version will be supported by canes every 10 metres or so. 73.

    Reply
  4. Richard Langley

    Yes, could you please give us some information on how the antenna was deployed and also how it was connected to the receivers? Did you use a balun of any kind or a ground or was the antenna lead-in (coaxial or just the antenna wire itself) just connected to the centre of the receiver antenna jack? And what was the gauge of the antenna wire and was it insulated?

    Reply
    1. Clint Gouveia

      It was supported by foliage lol about 5 feet above the ground. No balun, earthing etc. yet, but I am currently working on that, to convert it into a more directional Beverage. Just goes to show what’s possible with a simple (very) long wire. 73

      Reply

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