Photo Archive

40m Quarter Wave Vertical, Cornwall

40m vertical

Quarter Wave Vertical 9.6m in length

I’ve tried many verticals and never had good results APART from this one.

This is a 9.6m long fishing pole and the length of radiator is the same. I fixed 16 x 10m long radials to an insulator that I had lying around. I would have preferred this to have been aluminium but I already had three of these. Most of these bits were salvaged from the three-element vertical array with raised verticals that James and I made back in 2009. Each bolt was bonded together with some copper wire that is out of shot, underneath the insulator and the radials were politely scattered in an approximate radial system on the ground. SWR is 1.0:1 according to my electronic controller on the Acom 2000.

The results have been amazing but I do realise that I had two things on my side; location by the sea and almost no electrical noise. Bliss.

As I write this, I’ve worked 48 DX entities over about 7 hours operating time on 40m. Quite incredible. I’m a convert.

Nested Quarter Wave Vertical Antenna 20m and 10m

20m 10m verticalWith my recent success at building fan dipoles that are more “nested” than “fan”, I saw no reason why I couldn’t put up more than one element on my 20m band vertical to achieve a match on 10m. I ran up a 2.4m length of D10 comms wire up the side of the pole, around 2 inches away from the 20m quarter wave element. After trimming a few centimeters here and there, it tuned it at 1.3:1 SWR and all was well.

To make sure everything really was good, I applied a QRO carrier and watched in amazement as the SWR hovered for a few seconds before moving up and down and finally going off the scale with the Acom shutting down with an alarm (what a great amp that is!).

It took a while to track this down but it turns out the D10 military comms wire had melted at the guying point about half way up the 10m vertical element. I had tensioned it around one of the bolts on the steel three-way guy point to stop it flapping around and it decided to try melt the insulation and finally and weld itself onto it before blowing itself apart. The joys of QRO.

Under the hood, “Fan Dipoles”

10m and 15m nested dipole

10m and 15m nested dipole

Last year, with the assistance of Stu, M0NYP, I built a fan dipole out of D10 military telecoms wire for 80m, 40m and 20m for club field days. There was a fair amount of gap between each element, probably about 5 to 7 degrees becasue that’s what I thought you should do. For those people who came to either the Avoncroft Mills on the Air day, or the SSB Field Day, will recall the antenna. However, we lacked 15m and 10m though which I found a disappointment.

To become “all band”, I considered adding more elements to the Field Day antenna but experience has taught me that multi-band wire dipoles have a tendency to get tangled in the field. Adding more elements would probably just mean more tangles = less fun. In a Field Day situation, that’s a frustrating day out.

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2009 TDOTA

In 2009, rather than inviting the Girl Guides along, we put on a special event station instead and ran lots of stations, putting many people in the log. It’s amazing how many stations still haven’t worked the UK on 20m. Tim M0URX tells me that we still get QSL cards with hand written notes explaining how we are their first G (M) station. Superb.

2008 CQWW

James and I entered CQWW as a Multi Single event. We did a lot of learning that weekend and came back the next couple of years aiming for a top 10 in EU, quite successfully.

Kenwood RC-2000 Remote Control system for TS-2000

Kenwood RC-2000I’m pleased to report that after soldering hundred of connectors last Friday afternoon, the remote head for my marine-style TS-2000 installation worked perfectly, even though we had extended the head by 70 feet (21 meters).

How did we do this: The remote head requires extensions for a) 8 pin Microphone b) 2 core loud speaker and c) 4 core data. I had heard of a number of people complaining about RF feedback and other such “funnies” so I reduced the problems by over-specifying on the coax run (Ecoflex 10) and going completely over the top for the 8-pin mic and data cables.

The 8-pin microphone connector was a heavy-duty 8mm screened 25m reel from Farnell components at £90, expensive – but I felt worth it. The data was shoved down a neoprene style 4-core professional OFC microphone cable, as was the loud speaker.

The reason for the OFC microphone cable was an alert I had from a user on one of my Yahoo Groups suggesting that unless I used top-quality cable, the high frequencies might roll off on TX. Not being able to change the installation once the boat was built, I had no option but to buy the best cable I could find. As it happens, the audio is currently routed through the 8-core Mic lead, however I do have the option of running the mic audio through a spare pair from the professional microphone cable.

Tests demonstrated that nobody was wise to our remote head. No interference was discovered whether on our outgoing signal, nor on our data lines or speaker and control lines. Not one ferrite clip was used. Remarkable.

A first class effort. Thanks to james (M3YOM) for doing the soldering!

DX Weekend January 2008

Tim M0URX and I spent a cold evening in the Scout Hut experimenting with an elevated radial system on a full size quarter-wave for 40m, running a few hundred stations through the night.

2007 SSB Field Day M0XXT

I turned Dorridge Scout Group into a fully fledged club sation with the call M0XXT and put a number of young people through the Foundation Course. Aiden features in this photo archive, callsign M6TTT.