technology, amateur radio, scouting and me

New Antenna System – pt 1, Why?

We moved to the current QTH in 2009. We thought that we’d be here for about 10 years and then move on once I retired. As such, I didn’t take too much notice of the suitability of the QTH for amateur radio. Big mistake. The QTH is in a lovely location, but it’s hemmed in by other properties, it’s down near the River Great Ouse, and has a 20m high ridge running SW-NE behind it.

All of the above makes for a sub-optimal RF environment; mainly due to locally generated noise. On 40m and using my current antenna, I regularly get a noise level of S9+10dB.

We’ve now decided to stay here, so I need to make the best of what I have.

Current Antenna

Garden Plan

The plan of the property (dimensions in cm) shows my shack in the SW corner of a 13 x 8m back garden. There was a convenient concrete washing line post in the middle of the back fence, so up until now I’ve been using a long wire antenna made of Flexweave running in a wonky inverted-L from the shack, to the top of a fibreglass mast lashed to the washing-line post and thence to the back of the house. The Long-Wire is tuned with my trusty SG-230 SmartTuner; which I used at my previous QTH. There are also a set of tuned counterpoises that run around the fence.

It’s not a bad antenna, but it does pick up a lot of noise. It’s also been deteriorating over the last year or so. See later for why.

Options for improvement

As I see it, I have several avenues to pursue.

  1. Replace the current antenna with something better.
  2. If still no improvement, install a dedicated RX-only antenna (e.g. Magnetic Loop such as the Wellbrook https://www.wellbrook.uk.com/loopantennas/Loop_Antennas/ALA1530LN)
  3. As per option 2 but move the RX antenna to a quieter location and operate it remotely.
  4. Move the TX antenna (and K3S) to a quieter location and operate remotely.
  5. Move 🙂
  6. Give Up.

I’m going to start with Option 1.

Potential new antennas

I started off by exploring installation of a beam of some sort on a tower. This would have the advantage of directionality and reduced noise (if only from being higher). The challenge is the limited space. Even if I installed the tower in the middle of the garden, I’d only have 8m diameter to play with. I could get a Hexbeam or a Cobweb in without infringing on neighbouring properties, but nothing bigger.

Even without discussing this with the XYL, I discarded this notion, but did explore mounting a mast on the back of the house. Something like the Tennamast or something from MM0CUG https://www.mm0cug.co.uk/shop/steel-box-section-masts/. This could have worked, but after discussions with neighbours, I realised I would get objections and decided to explore other avenues first.

The alternative is to installed a better wire aerial, and that’s what I’ll cover in the next part.

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