Saturday 23 January 2010

Out in the cold!

The dry weather today finally allowed me to get my Wellbrook loop receive antenna up outside. I removed it from the loft this morning. It is now out in the cold, temporarily mounted in the Garden, on a length of plastic pipe. This is not going to be its permanent home,it is a little too visible where it is at the moment and the YL doesn't like it! I think I will end up putting it on the back fence but I will need to extend the coax cable feeding it. It will also need a piece of wood or plastic across the loop itself to strengthen it. At least for now though I can test it.
I was inpressed with the loop on the low frequencies, particularly 80 and 160 metres as well as Medium Wave, even when it was loft mounted. As good as the loop may be however it is not a "magic" antenna and it still picked up lots of noise in the loft, although I must say less than a wire antenna would have.
My first impression of using the loop now its outside was the way in which I could null out some of the local noise here. On some HF frequencies I am getting S9 of noise from an "internet over mains" system or Homeplug as I believe they are called. By carefully positioning the loop I can reduce this noise by 4 or 5 S points.This excercise did remind me that I must try and trace the source of this noise and consider reporting it to OFFCOM. It is only audible on my external antennas, a portable radio with a telescopic antenna doesn't receive it.I guess this means its not coming from a near neighbour, and may be a few hundred metres away.
The loop is certainly quieter now that its outside and as I get time to use it I will report more on its performance. I am looking forward to testing it on the amateur and Broadcast bands.
As an indoor antenna I would say that it is superior to a wire dipole in the loft for example but don't expect too much. I have seen reviews where it has been said of similar loops that they received fine with very little noise even when placed in the shack! That has not been my experience. I would say however if you are limited to an indoor antenna the Wellbrook loop will give reasonable performance and on some bands is comparable to an outdoor wire.
As I type this I am listening to a QSO on 160 metres between two G-stations, Both are stronger and clearer on the loop than they are on my Inverted L wire. Quite amazing when you consider the compact dimensions of the loop.

1 comment:

  1. That is pretty amazing. A few months ago I got a PA0RDT active antenna, with the hope that I could locate it where it would not pick up the local noise source. But I could not find anywhere within the boundaries of my property where I could not receive the noise. It does work nicely as a noise antenna for my MFJ noise canceling box, though!