Friday 18 December 2009

Loop update



I have had a bit more listening time with the Wellbrook loop now and here are my thoughts:

 *It is very effective on the lower frequencies. On top band (1.8mhz), signals that are inaudible on the random long wire are clear on the loop. Signals that were S1 on my inverted L (which to be fair is not designed for 1.8mhz) were S5-6 on the loop.

*On 80 metres the loop eliminates a lot of noise that is present when using the random wire. It is comparable to my inverted L which is amazing when you consider the size of the loop and the fact that it is currently in the loft.

*The loop is VERY directional on the lower bands, particularly Medium wave where rotating the loop can increase a signal by at least 8 S points on the meter! It is of course difficult to rotate the loop if you don't have a rotator. If you were a medium wave Dxer and using this loop I think a rotator would be pretty much essential.

On the higher bands the loop appears just as noisy as the random wire. Of course this is an unfair comparison since the wire is outside. I did try a wire receive only dipole in the loft at this QTH a while ago and abandoned it is at was so noisy, in comparison to that the loop is much better.

I really think the loop will come into its own when mounted outside. As an indoor antenna it is quite impressive but it does pickup noise as any indoor antenna will. It is quieter on the lower bands however and particularly impressive on 80 metres.
Tonight's picture shows the little amplifier box which sits between the receiver and the loop.

2 comments:

  1. Hello Kevin,

    Great to hear more news of the loop. Interesting that it outperforms your loft-mounted dipole by receiving much less noise. Sounds like if you were restricted to indoor antennas then a loop would be a good choice.

    Tropical Band Broadcast band DXing was an interest of mine but impossible on the indoor wire I had at the time. Looks like the Wellbrook loop might shine here......

    Good luck with outdoor testing! 73 Adam

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  2. Hi Adam,
    I am not sure the loop would be good for tropical band if it was indoors. I have been listening round 6 to 7 mhz today and it is a lot noisier than the wire. I know tropical band is a bit lower and I will give it a try on those bands. The loop seems to come into its own below 4Mhz but is very directional. I think the best way to look at the loop is that if you HAD to have an indoor antenna it is better than a wire. Personally I think this one will will perform a lot better outside.

    73 De Kevin

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