Screwdriver discoveries Part 3

Following on, I was advised that the original design of this antenna ran at 5v and received a bit of history about it. 

So, that's led to some additional purchases - namely a 5v regulator. 

The PWM module - this will run about as low as 3v. Hopefully this should do the trick to slow it down for fine tuning.

This is the module I'm planning to use to cut the 12v down to 5V.

Neither module is particularly expensive - available for about $10 each. I certainly don't have the parts floating around to replicate either, and I suspect trying to DIY either would cost me significantly more. 

Now that I'm fairly tied up waiting on Australia Post, I've moved on to the next parts of this puzzle: how to mount it, and the ground plane problem.

I can't mount this on my car - I don't have a tow bar, and it's a sedan rather than an SUV. I also don't fancy bonding all of the panels together to make sure that they're well earthed. 

This begged the question - how do a I hold up an antenna that's targetted being on a vehicle? Eventually, having thought of various rigs, the simple solution based on experience hit me - use a PA speaker tripod. They have nice, wide legs, they're heavy duty and they're designed to hold 50-60kg at height. Hopefully this will translate into being able to hold up a screwdriver reasonably well. 

I should be able to get it in nice and close to the car to make use of some reflection, even though I won't be connecting to the cars body. It's also usable if I want to get away from the car. 

This creates that ground plane problem. I don't have one if the car isn't it. I've spent the last day procrastinating about different ideas, ruling out things like thermal blankets as the mylar isn't electrically conductive, and wound up going back to an idea that I vaguely recall Peter Parker VK3YE putting in a video once - using a run of aluminium foil as a portable ground plane of sorts. 

I seemed to recall he used a roll of contact (clear adhesive used for covering kids school books for protection) to help give it some strength. Luckily I knew the location of a 5m roll of long ignored contact sitting in my step daughters wardrobe. Slowly but carefully I peeled back the backing, laying the foil down on top. At the start I took a piece of stripped wire, wrapped it in another piece of foil, laid it on top then held it down with contact, giving me a way of providing an electrical connection back to the radio. 

This wound up at around 4.5m long - the contact is wider than the foil, so the edging is folded over the top of additional support, and a few strips exist where I've cut the foil in sections and had to layer them.  It rolls up nicely around the cardboard tube from the contact role, and the wire wraps around the outside to keep it together. 

I don't expect miracles from this, but it's cheap, easy to make and rolls up quite nicely to make it portable. I'll just need to remember to throw in a few things to act as weights to keep it down on the ground.

I've also given the screwdriver a slight cosmetic makeover - the PVC tube was looking a bit ragged, so it's outside drying after a quick coat of paint. The whip - being aging copper sheath over a solid wire core are now covered in shrink wrap. I covered it in 10mm wrap and wound up running it over the gas stove to shrink it. My usual application of a lighter really wasn't up to the task of something quite so long, but the stove made short work of it. I just need to find something to cap the top off with.