More Lessons Learned

 

 

Joe Chester MW1MWD makes some changes to the antenna setup and contemplates a new transceiver.

 

 

Last month I talked about the Buddipole (BP) antenna system and about some lessons (reminders from the past) about antenna heights and radio propagation. What else have I learned? The first challenge is mechanical stability. There are no shortcuts here – it’s a safety issue, so just spend what it takes to be certain that what you put up is not going to come down if someone bumps it or trips over a tent peg. I took a short cut, with hilarious results. But no harm was done. Even if there is no wind, guy it down or attach it to something that ensures it won’t come down. I threaded some strong line through the holes in the Versatee in order to clip guy ropes to it.

The second thing I did was to replace the banana plugs on the choke-balun (part of the BP system) with ring terminals, secured by stainless nuts. This was done after several days of poor connections and with advice from the B.U.G people. I put out a request for help and had nine replies an hour later − thanks again lads! There is a warning from the B.U.G people not to tighten the nuts too much because it might pull the terminals off but this arrangement seems more secure to me. The antenna analyser is now happier. And this is the third thing I learned. When playing with antennas, get an antenna analyser – mine is the Sark100 from EA4FRB.

 

Installation Routine

The routine with the BP is to put it up in the air with the recommended settings, then check the SWR across the band. Adjust the length of the whips or move the coil settings until you get the results you want on the analyser. Then plug in the radio and start operating. Now please realise that this is 3m, sometimes 5m up in the air. This means having to take it down every time to adjust it and put it back up. So, when you get something that works, measure and write everything down. This way, when you get out portable, you have a starting point close to the right setting. A few tweaks are all you should need. Scott’s book (see last month) describes many recommendations for BP setups for all bands of interest and a really interesting comparison of dipoles and verticals (with radials). Budd, the inventor, favours an L shape up about 2.5m, especially when operating close to the sea, because this provides a better ground effect than ‘normal’ garden or pavement. Changing the angle between the two arms also changes the impedance, producing a better match to the 50Ω expected by the radio.

 

Learning Lessons

My guess is that you think I’m now an expert on the BP, or an idiot for doing all this work. My cynical friend M certainly thinks the latter! In the hot weather we had in the summer there is a limited amount I can do in any one day. But that’s not how I see it. Amateur radio is as much about figuring out what works as it is about collecting squares. For me, this is where most of the fun is. So, after the last outing, I will be testing my configuration in the garden a few times more before the RWWR-4 trip. I won’t, however, get obsessional about it – no one will notice if the SWR is a bit off or the radials are a bit short. Setting up an adequate portable antenna is not hard (unless you’re a hard-core contester or DX chaser). Making it hard kills the fun!

 

The Radio

The second major issue coming out of the RWWR project so far is the limitations, for me, of the Icom IC-706. Lovely radio, I’ve had two (I crazily sold the first one). I’ve owned the present one for over 20 years, even went maritime mobile with it! But, as I said previously, it’s a hungry beast – 2A on receive and 20A on transmit. Which means I can’t use the battery in the car – no point in getting stranded because the car won’t start. And running the car engine while parked up just to run the radio seems wrong in this day and age.

More importantly, the IC-706 needs 13.8V to run properly. In fact, this is not actually about the radio at all. I see M is grinning at me now! He could have mentioned this earlier, but that’s not his way. It’s all about that 12V car battery. All 50kg of it. The name of it is a give-away − 12V battery. This means that it’s unable to deliver the 13.8V that the IC-706 requires for full power operation. It also doesn’t hold much of a charge when 20A is pulled out of it while I’m transmitting. The voltage, marginal at 12V at the start, quickly drops to unacceptable (to the IC-706). And the weight of the thing, twice, out and then back in, every time I want to go portable. Of course, the answer has to be a Land Rover Defender, or equivalent, with a second ‘services’ battery permanently installed in a secure battery box and a battery-to-battery charger to charge it from the car alternator. And a battery conditioner to keep it delivering 13.8V. Sorry, are you getting exhausted? Well so am I.

In radio terms, my IC-7300 runs rings around the IC-706, especially in receive sensitivity. In a quiet spot, out portable, the background noise on the IC-706 is very high and I could clearly hear breakthrough from power line internet modem bursts while sitting on top of a cliff. This may defy logic but it’s what I heard. I’ve also got used to the panadapter display of the IC-7300 at home. So, as well as finding a better battery solution, I also think, almost regrettably, that it’s time to consider trading up the radio.

My Accountant, of course, has a view on this, as usual. “I’m buying a new radio” was not the best opening gambit at dinner one Friday night. This was closely followed by “I have to buy a new battery too”. To which the answer was “you already have a battery”. Yes indeed, but it doesn’t really work. Convincing her took some doing because she really doesn’t ‘get’ amateur radio as a hobby. I bored her silly at the Loughborough Radio Show some years ago and she’s never fully recovered. In my defence, I have to say that I don’t get cross stitching or Archers addiction, although many others do. I finally brought her round by promising to sell some stuff online, as well as trading in the IC-706 (someone will get a bargain!). We’ll see how this goes. But I’m looking forward to having a small, modern, low-powered battery-operated rig soon. And no more car battery lifting exercise.

 

Covering 2m

One of the issues all of this will create, once the IC-706 is gone, is about 2m SSB, or even FM in the car, which is presently covered by the IC-706. I’ve not got a solution yet. I spy a transverter that would go nicely with the IC-7300 at home for 2m SSB so I’ve put this on the list for approval by the Accountant. In practice, I drive the car, especially on longer trips. A mobile FM rig should be useful. But it’s not that easy because I’m not too happy (and neither is the Accountant) with me driving down the M4/M6 while chatting on the radio. This is an area to be explored (I’ve hidden a small sum in the agreed budget to cover this, if needed!), but I’ve enough going on at the moment to worry about 2m SSB.

So, can you guess what’s coming next in the continuing saga of the RWWR project?

 

 

This article was featured in the December 2018 issue of Practical Wireless