RadCom - It's Been a While...

Now, this blog is primarily aimed at encouraging amateur radio on a pocket-money budget.

For example, if you look up the 'I-Am' end-loaded vertical antenna I wrote about here some time ago now, you will save yourself about £200 over the commercial version and have significantly lower losses in the feed system. More importantly, you will learn more about antennas, and even be a little less frightened to experiment with non-established designs; there's little to get wrong, if you follow the basics.

So, it's disappointing, to say the least, to find RadCom, as so many other hobby magazines, reviewing equipment within its pages that doesn't so much save money as encourage you to spend more of it.

Turn to the Christmas 2014 edition, page 32.  Here's a review of the 'Whizz Whip' - a simple telescopic whip antenna currently primarily aimed (given its direct male coupling) at the smaller Yaesu mobile transceivers.

Now, there are people who can use most types of equipment, and the 'Whizz Whip' is probably useful in some circumstances.

What I wonder about is whether any situation makes the 'Whizz Whip' a good antenna choice, given that it costs - wait for it - 5p short of £100!  As the review diplomatically asserts, a whip like this needs a counterpoise to reduce RF feedback from the I3 current, and help make the situation more stable altogether.  It doesn't come with one!

Which kind of brings any sensible operator to ask: why not just use a simple homebrew inverted-L, vertical dipole or something like that?  Total cost for one of those can be pennies, maybe a couple of quid if you buy a new SO239 connector (not that you in fact need one of those!)

RadCom repeats the sin, rather, when it moves, at page 61, to review what's ambitiously called a "quarter size" G5RV.  At least this only costs £24.99, giving the maker a pretty low margin all in all.

But, come on!  Why would you buy an antenna like this?  Can't you cut some wire and solder?

Let's imagine you have little space, which is the justification, it seems for the review.  You can build your own twin-fed dipole for maybe £15 if you bought all the stuff, a lot less if you have an established junk box.  You don't have to give it a name - it's not really a G5RV at all, more a doublet.

What really annoyed me about the '1/4 size G5RV' review was its use with 30m - that's 100 feet - of Mini-8 coax.  Whaaaaat?  30 metres?  If you mounted the antenna at 10m, and your garden is meant to be small (the justification for the antenna and review), that gives you 20m of coax to eat up somewhere on the ground, remembering that the height is covered by the twin line!!

I think a realistic assessment ought to have been made with no more than 15-20m of coax.  Of course, the SWR figures would be somewhat worse under that condition, due to coax losses being reduced.  Even then, it's a question as to why you wouldn't simply build a shortish doublet fed only with twin to a 4:1 current balun and a tiny section of coax to make it to the ATU - far lower losses even at very high SWR - and cheaper. At 5m a side (2m longer than the commercial unit), you could work 20m and up efficiently.

Quite why RadCom is reviewing a quadcopter (p68-69) is anyone's guess.  But that guess might be related to the advertising income, given that it featured prominently - read expensively - on the back of last month's RadCom.

And then we come to some stuff about propagation beliefs being wrong.  I tossed the magazine aside when I read that one-way propagation might be down to higher noise at one station over another.  Tsch!..