I thought the following might be interesting for the newcomers to the hobby, and help explain why many amateurs use more than one aerial. I took delivery of one of the low cost verticals this week, and made some comparisons with my trapped dipole. For interest’s sake, I also included my yagi, just to see if the cost and effort was justified .
We mounted the review X80 vertical, from the Snowdonia Radio Company, on Wednesday evening 15 March 2011. It’s on a metal stake next to the corner of my fish pond. We used an antenna analyser, and established the 80m SWR was 6 to 1, but all the other HF bands 40m to 10m were well under 2 to 1. There were no radials used, in line with the suppliers recommendation, but I think this type of vertical might indeed benefit from them…
As expected, the X80 performed better as I went from 80m to 10m, and the dipole was better in the reverse direction.
As signal strengths are difficult for me to determine accurately, I’ve recorded MP3 comparisons over the last three days on 80m through to 10m. I’ve deliberately selected signals right on the limit, to show the capabilities of the aerials, after all, there’s little point in comparing strength 9 signals on the doorstep. I’ve used 3 antennas in the comparison.
A trapped dipole, which is 108 feet long, trapped for 40m, and fed with balance 75 ohm twin feeder, at a height of 10 metres. It is connected to the rig via a 1 to 1 ballun. I have marked this with one ‘beep’ in the recordings.
The second antenna is the Snowdonia Radio Company X80. It is a 5.8 metre tall aluminium vertical with a 9 to 1 un-un at the base. It is fed with 20 metres of RG213 coax. I’ve marked the SRC X80 with two ‘beeps’ in the recordings.
The third antenna is a 3 element Steppir at 11 metres. It is a rotary dipole on 40m and 30m, and a 3 element yagi on 20m to 10m. It is fed with 30 metres of Westflex 103, and there is a 1 to 1 ballun at the feed point to the aerial. I’ve marked this with three ‘beeps’ in the recordings.
I used an ATU once, for the X80 recording on 80m. All other recordings
are without any tuning.
On 80m, you will hear SV2HJQ in Greece. Firstly my trapped dipole, then the X80, then back to my trapped dipole. The dipole gave strength 9, the X80
On 40m, you will hear VE2TC in Canada working some Spanish stations. I have changed the order of the antennas, so they progressively get better. Firstly, you hear the X80 with 2 beeps, then my trapped dipole with 1 beep, and then the Steppir with 3. I then repeat the X80, dipole, and Steppir sequence again.
On 30m, you will hear VP2V/G3PHO in the British Virgin Islands. Firstly, the trapped dipole, then the X80, then the Steppir.
On 20m you will hear HZ1ZH in Saudi Arabia. First the trapped dipole, then the X80, then the Steppir.
Also on 20m, you will hear zl1BD in New Zealand, first the dipole, then the X80, then the Steppir.
On 17m, you will hear KH2/WX8C in Guam. Firstly the dipole, then the X80, and then the Steppir
On 15 m, you will hear V521NAM in Namibia. First, the dipole (no copy), then the X80, finally the Steppir.
On 12m, you’ll hear ST2AR in Sudan. Firstly the trapped dipole, then the X80, and then the Steppir.
This station was worked using the X80 and 10 watts.
On 10m, you will hear LU2NI in Argentina. Firstly the dipole, then the X80, and then the Steppir.