The Gutter Beam             

Going full circle with antenna projects.   



Over 35 years have gone by, but I still have very fond and clear memories of my earliest experiences with CB radio, and how ignorance in RF theory, combined with woefully inadequate funds, forced many of us to construct some truly off-the-wall antenna setups as we sought to slowly and painfully climb our way up the ladder into the "big leagues" of CB radio operation.  I remember all too well, the time when I finally acquired my very first 23 channel, 5 watt CB radio in 1974, and of the homebrewed 1/4 wave whip which I had fabricated using soldered together car radio antennas, scavenged from the local car wash, and mounted to the back soffit of my house.  It was a crude antenna and, as one might suspect,  it didn't put out a very big signal compared to those who had "real" commercially made base station antennas.  I was lucky if I could talk 5 miles away with any reliability.  Those early times were a bit tough and painfully humbling. Many years have since gone by and, during that time, increasing cash flow allowed me to steadily improve my antenna standing.  My first jump was to a 2nd hand 1/2 wave ground plane. Then I bought a new 5/8th wave ground plane, and eventually I made it all the way to a 3 element Avanti Astro Beam on a 40' tower.  I was at the pinnacle of my antenna prowess by the early 1980's and at that point, I was "getting out" about as well as I could considering my relatively low elevation compared to my immediate surroundings.  For that formative 25 year period following my initial homebrewed antennas, I always had a decently made commercial antenna, so I didn't think all that much about homemade CB antennas much after those first attempts.  I didn't think that a homebrewed antenna would perform well enough to be competitive in a CB application to be considered.  But all that changed in 1999, when I moved to a new home and began the task of putting together a usable radio station again.  It was not a simple matter of just re-installing my previous setup however as there were some interesting new challenges.  My new development builder's deed restrictions stated, among other things, that I could not have a radio transmitter antenna which extended above the roof line and could be seen from the front of the house. That pretty much put the kibosh to any plans to put up my tower or any other full sized CB base antenna designed to be roof mounted.  But during the coming winter, I temporarily threw up my Avanti Sigma 4 on a 6 foot pole and located it in the unfinished "wooded" area camouflaged among the brush and saplings of my new yet-to-be-graded back yard.  That seemed to work to some degree as I was able to talk back to the old town gang (barely), now some 25+ miles away.  But come spring, the yard crew came in and graded and seeded my yard and I had to take the antenna down.  So now I was faced with a problem to solve. I could not put up the Sigma anywhere else but on the ground, and once the yard was cleared, it became a fairly conspicuous eyesore.  It couldn't be mounted to the house, without violating my deed restrictions.  I had thought about utilizing one of the fairly tall trees behind my house to hoist the antenna into, but the work building and grading the house and yard damaged their roots and they soon died, which then necessitated their removal.  My only other practical short-term option was to stick a 102" mobile antenna to the aluminum rain gutter on the second floor roof of my house. A 9' whip would not extend much above the roof line, and it was also at least 20' above the ground so I figured it might work acceptably.  I had some initial reservations about going this route, remembering just how badly my original "whip" antenna had faired 30 some years prior.   But to my surprise, it seemed that this setup actually worked fairly well judging from the receive side since, unlike my 1st homebrewed 1/4 wave whip antenna in 1974,  I had no problem hearing stations 20 to 30 miles away.  I could talk reasonably well too, at least compared to what I had been used to at my old location.  This all was possible because I was now at 400' ASL compared to my old location which was at a measly 160' ASL.  So it was with a twisted sense of irony, that I now find myself, some 30 years later, running a homebrewed antenna system very similar to what I had when I first started out, but this time working considerably better.  As they say, height is might.  But talk about Deja-Vu.....

This antenna system was sufficient for the first few years at my new home.  I wasn't all that active on CB as of yet, as I was still trying to get a feel for the locals in this area.  Plus, the 11 year sunspot cycle was still winding down, so there was a lot of DX noise and heterodyning to deal with.  Every once in a while I'd catch someone in there and say hello.  So there was no real incentive to better my signal.  But lately that's all changed. There's been a general resurgence in activity and a few of us have started becoming interested in operating vintage 1960's and 70's radios.  So even though my kludged up antenna system worked surprisingly well for what it was, the distance between my location and the majority of the group is about 8 - 10 miles.  At that distance, my signal is not all that strong, especially compared to the closer locals.   Consequently, I'm usually the first one taken out by a jammer or when the local noise jumps up or DX conditions start running.  Plus, after a few years of listening and getting to know who the locals were, I came to realize that very few people in this area run stock legal power.  Most are running some sort of amplifier, which probably accounts for a significant portion of my seemingly good receive performance.  I'm not used to being the guy with the weakest signal, so I started thinking about what I could do to improve my situation.  Not wanting to be too obtrusive with my antenna system, at least until I could find out for sure if the deed restrictions have expired now that the builder has finished my development and moved on, I wanted to see if I could make some improvement to what I already had.  As luck would have it (And it's strange that I would ever have good luck), my rain gutter pointed in the direction I needed to talk to. It also faced the direction 180 degrees behind, where a rival group of people talked, and created a lot of co-channel interference.  With this in mind, I started thinking about making some sort of makeshift beam.  A beam would be an ideal solution. It would increase my signal (and receive) in the direction I wanted to talk, while dropping down the interference in the other direction.  During my initial planning, I recalled another flash from the past when my good friend Mitch was experimenting with his own homebrewed antennas and had made a bi-directional beam utilizing 2 dipoles which he could alternately feed via a switch box. That contraption worked fairly well so I thought I could come up with a similar result.  Since I didn't have a full dipole, (the rain gutter provided my counterpoise) I wondered just how well a beam would work with just the "top side" being utilized.  But I was willing to experiment a little to find out (after all, isn't that what makes it fun?).  So I made a reflector element from spare aluminum which used to be part of an old antenna in a previous life, combined with a section of push-up pole from a tent I had.  I set the length of the element to 114", which was equivalent to what the plans I had for a 4 element beam reflector top section called for.  I spaced it 63 1/2 inches from the driven element also according to the beam plans.  The total time it took me to install this "super-kludge" was less than 1/2 hour.  But when it was all said and done, I did notice a definite improvement in signals coming from the east as well as a corresponding decrease in the signals coming from the west.  My signal to most of the group jumped up by about 6 db which is not too bad all things considered.  The jump in receive signal from the people in town was even more drastic with some jumping up over 10db.  The back rejection was a little disappointing though as I could only drop them down about 10-12 db.  I'm pretty sure that if I adjusted the element spacing and reflector length, I could improve on this, but it would require a lot of tuning with a constant available signal.  Not something I want to deal with just yet, but might be interesting later on.

The whole experience brought back memories of those early pioneering days of radio, when little changes were made and signals were eagerly checked to see how much, if any, improvement was made. It felt good to be experimenting again, although the engineer in me tells me I should probably have tried to model this thing on EZNEC or some other antenna modeling software first.  But I didn't have that tool 30 years ago, so I'm no worse off now.  But if I decide to make any further improvements,  I may cheat and try modeling it first before I put it physically together   I also have to realize that the inverse square law is working against me, and no matter what antenna I eventually put up, I'm still 10 miles out and I'll never be able to compete with people 1 or 2 miles away, unless I elect to run some serious power, in the neighborhood of 700+ watts, which is not something I want to do.  Stay tuned for updates.

Update 2007: The Gutter Beam is history. I never tweaked it any further. Instead, I managed to put a real 3 element beam up on the roof of my garage, which performs far better than the homebrew beam (and I can turn it!). I removed the reflector element from the gutter beam, but kept the original 102" whip up to use as a secondary receive antenna.