Having experimented with an attic dipole, I decided that a better antenna was in order so that I could use my SDR properly. To this end I purchased a 9:1 unun (unbalanced to unbalanced transformer) and ran a 10m (approx) length from about 2m inside the attic to outside and to the far end of the garden (about 8m further). The antenna works reasonably well, particularly on the bands above 14MHz. However being partially indoors, it does pick up a fair bit of noise. Which is when I decided it would be better served as the noise pickup for my main station, thereby leaving teh Wellbrook loop free for use on the SDR-IQ.
If our TV is off though, the noise level is generally acceptable and it is certainly better than the attic dipole. Of course the main antenna is quieter, as the feedpoint is as far from the house as possible.It is important to have as much choice as possible when it comes to antennas - even a ‘make do’ antenna (like my attic dipole) can produce surprises, and just sometimes you might be able to hear something on a second antenna that is not audible on your main antenna (it could have a null in the direction of the station you are trying for or may not pick up an interfering signal as strongly for instance). Also, antennas quite often work on bands they are not designed for, just experiment, it’s fun and you learn an awful lot about what works and what doesn’t!
The VHF antenna has been replaced - I was using a 5 element vertical yagi, which was great, but limited to band 2 frequencies. I decided to purchase a triband vertical white stick. I used to have a dual bander which worked pretty well, so the natural progression was to get one that covered 50, 144 and 430MHz. I mounted this in the attic and removed the yagi, because of space and interactivity issues. Pleased to say the vertical works well on most frequencies and I am able to hear plenty of stations.
I recently updated my main computer from a laptop to a base unit so that it was capable of running the latest SDR sofware packages, that take advantage of increased RAM and CPU power. It is specced as follows: Quad Core i5 processor running at 3GHz with 16GB RAM, 1GB graphics card, SoundBlaster Audigy ZS2 soundcard, and a 1TB hard drive with 23” and 21.5” HD monitors.
So far it is proving to be a very fast and powerful PC and makes using the SDR a pleasure.