A Trap Vertical in the Forest


How often have you tried your luck with a trap vertical antenna?  They are often praised for their ability to work the bands in spite of restricted spaces and HOAs.  But, have you ever tried to use one that’s planted firmly in a forest of dense foliage … amid the tall pines and oaks?

Lately, I decided on a whim to try the forest vertical, ignoring for the most part the admonitions that came back to me when I’d floated the idea.  I used a 4BTV with a couple dozen radials, ground mounted in a wooded lot of about a third of an acre, which contained at one point 126 trees.  I’ve since removed a number of them, but many still remain.  I found a space where the minimum disctance in all directions was about a quarter wavelength on 20 meters.  Could the signal make the trip through  the greenery to the outside world?

The first weekend I snagged about a dozen countries from the North Carolina QTH, including Chile, Argentina, Finland, Sweden, the Cayman Islands, and French Guyiana.  These are easy picks for most any Yagi, or even a dipole in good conditions, but the conditions were really pretty terrible.  The MUF hovered just about even with the top end of twenty meters.  Maximum usable frequency is not necessarily easily used frequency HiHi.

Figure: The radial base of stainless steel is a must IMO

Try not to look at the twist-off tie-ins put onto the base right before the rain!  Other than that, I thought the base both looks good and works better than the suggested tie-offs to the ubolts and nuts to secure the radials.  The plate adds only 20 bux – and makes the radials a breeze.

All in all, I’d say that it’s possible to work the bands with a vertical in the woods, if one allows oneself a little leeway on expectations.  My signal reports are a little lower than with the dipoles, but due to the radiation angle the contacts are more DX-ish.  So, it’s a trade off that I’ll make, while I’ll keep the horizontal dipoles and loops for the less DX-ish stuff.

I put down 24 radials to start, and will likely add a few more as time permits./

Figure: Six pound sledge does do a number on the iron pipe support

Analog Radios more Resistant to Electrical Storms?

Over the years I’ve had a number of radios, both digital and analog. In that time I’ve had a number of damaged radios that were impacted due to (I assume) electrical storms in the vicinity of the QTH of the damaged gear.  I have always used lightening arresters and so forth, and proper grounding, but there is a certain amount of energy that gets into the shack from nearby storms that are not producing any direct hits, but still do manage to produce a lot of ambient energy.

I’ve noticed that the old analog radios seem to stand up to the storm, so to speak, better than the digital ones (now this is anecdotal information that only involves four radios, so it could be insufficient for the making of any conclusions).

In the first case I had two radios hooked up to the antenna and rig switching network, with one being an analog (oldie from the seventies) radio, and one being a newer digital radio.  The digital radio suffered a failure, while the analog radio (the oldie) did not.  The second case was similar, with another older analog radio hooked up at the same time as a second digital radio.  The result was also similar, as the analog radio sailed right through and the digital one suffered a failure.

If you think about it, the old analog transistors would seem to be hardier things than a fet or a logic chip.  The MOS technology builds a capacitor into every device, which may not handle a lot of voltage. Often, they do not.  Sure, some of the big MOSFET power transistors can take higher voltages, but many of the others are very low voltage devices.  Any old NPN analog transistor will likely have a collector-base breakdown of over a hundred volts, and often have a collector-emitter breakdown limit of near that amount.  So, they just seem to be the hardier devices.

I suppose that one could go back to the old tube type radios for even more hardening, but that’s too rustic for me.  I’ll stick with the old analog dogs, that are old but not antique!  I guess I just have a hankering for the old things, and this is just another rationalization for me to collect more of them.