Or should that be ‘antennae’??? Whatever… Welcome to the 3rd in a series of ‘talks’ that I hope will introduce the new hams to the wonderful world of amateur radio. It sometimes catches me up to realize the significant responsibility we have been granted in getting our license. Given the radio spectrum we are allowed to play in and the desire (especially in the UHF and beyond bands 2Ghz, 5Ghz, etc.) for commercial, military, and medical use of those frequencies for device interconnection, we have a huge responsiblity to play nicely and respectfully with our radio neighbours.
So that aside, what I want to talk about in this session is probably the second most important part of your radio station — the ANTENNA. (I’ll leave you to figure out what the MOST important part is! :-)) My feeling is that when considering $$ investment in the hobby, you should spend the majority of your available funds on your antenna (or antennae!). I know we all want to have the latest and greatest technology/toy for our rig (transciever), but when you get down to the realities of the hobby, the greatest expenditure of time and effort will probably be on getting that ‘wire in the air’. And while radio technologies and features will come and go, your antenna system is really the final determination of how well you’ll be heard on the air. Unless you’re young, energetic and really enjoy climbing various structures/trees/etc. or playing with launching devices, you probably won’t be changing out or erecting new antennae every weekend. So, spend some extra time thinking about what types of communications you want to engage in, what frequencies you want to play on, and what kinds of antennae you need to make that possible. Spend the $$ and time now to get what you want and it will be a source of pleasure for a long time to come.
Of course, you also have to take into consideration the constraints of what’s actually POSSIBLE, given your circumstances. In my case, I love playing with HF (shortwave) for talking to hams all over the world and VHF/UHF for local & emergency communications. This requires two different types of antenna systems. Unfortunately the building scheme for my neighbourhood prohibits any ‘visible’ antennae except for small satellite dishes for TV reception, so although I would LOVE to put up a 75 foot tower with multiple beams, inverted V’s and VHF/UHF dipoles that would be the envy of the local police and fire companies, that’s just not possible. (Did I mention my wife also said ‘NO’ to towers in the backyard????). So, I have to be a little craftier when designing, building and installing my antenna farm.
In our last blog, we talked about the first rig (radio) most likely being a handheld transceiver, since this is one of the easiest ‘all-in-one’ solutions to get you started — even coming with an antenna!
Well, let’s take a look at its ‘interface to the ether….’. Typically, the antenna provided will be about 6 inches long and completely encased in some plastic/rubber material to make it somewhat water/splash proof. (In ham lingo, they are known as ‘rubber duckies’ — don’t ask me why….) If the handheld is multi-band (VHF/UHF) then the antenna will have been built as a compromise to work OK on all those frequencies. It won’t be great, but it will do the job without damaging the radio’s output transistors.
There is a maxim among hams that the more metal/wire you can get in the air and the higher you can get it, the better. Generally this is true. There are exceptions and limiting parameters, but that discussion is well beyond the scope of this blog. So how does this apply to your handheld? Simply put, if you get a longer antenna for the handheld, it will work better! There are numerous options available from either the radio’s manufacturer or 3rd parties — examples include longer flexible antennae, multi-segment whips
or even antennae with magnetic mounts you can attach to whatever metal parts you can find on your car or on a filing cabinet in your office! And if you really want to extend your range, you can buy a ‘base station’ type of antenna (the one I have is about 6ft long) and mount either on the side of your house or in your attic
For these latter ones, you’ll probably need to buy an adapter cable that converts the antenna connector on the top of the radio (usually an SMA male or female — no gender fluidity here) to the common SO239 used on bigger antennae.
I use this one to connect my DMR handheld to my base antenna in the attic and run the DMR talk group on Wed mornings. A mag mount or base station antenna will also serve you well if you decide to purchase a more powerful VHF/UHF transceiver for use in the the home or in the car.
For those of us that like to play on HF (shortwave) frequencies, things become a little more challenging in terms of getting enough ‘wire in the air’. To effectively broadcast signals at these frequencies, there has to be an effective ‘match’ between the antenna and the output of the transceiver. (Remember those discussions of Standing Wave Ratio from the Basic Qualification Course???) This means that the amount of wire/metal required is much larger/longer than at VHF/UHF frequencies. There are ways of fooling the transceiver into thinking it’s looking at a longer piece of wire but that does reduce the effectiveness of the antenna.
There are literally hundreds if not thousands, of different configurations for antennae. I’m not going to go into the pros and cons of them here — there are volumes of articles and books available on that subject. Your best bet is to talk to other hams in the area and see what works for them. HOWEVER, keep in mind the criteria I mentioned at the beginning of the blog:
- The antenna system is going to take the most time and effort to set up and get running. It is your primary long-term investment. Don’t skimp on the $$.
- Design and build an antenna system appropriate to your circumstances and capabilities. It’s great to have the space and neighbourhood for a tower and beam, but not all of us can have that. Some of us have to ‘hide’ our antennae out of respect for our neighbours, our spouses and our environment….
- The maxim of ‘more wire/higher is better’ applies, but again be cognizant of your capabilities. Also think of maintenance requirements in the future.
- Be aware that you will be limited by your location. Again, high on a hill with a view of the horizon is definitely desireable but very few of us bought our homes with a view to how the antenna farm would work….. And, there may be significant electrical/radio ‘noise’ in your neighbourhood. This is becoming more and more of a problem with the proliferation of solar panels, LED lights and cheap power supplies (Yup, they all broadcast!)
Here’s an example of a local ham with an acreage who was able to install a fairly elaborate tower and antenna system. He’s on a farm.
Personally I’m envious, but what can I do? I have limitations….
My setup is simpler and definitely more covert.
See the antenna farm???? Well, the attic contains the VHF/UHF base antenna and a 7-band HF fan dipole antenna, covering 40m to 6m bands. A fan dipole is basically multiple wire dipoles attached to a single central connect point.
The wires just run along the trusses/rafters in the attic. The other HF antenna (my main one) is a piece of wire attached to the side of a cedar tree in my backyard.
See it? Maybe just the base??? Well, here’s what it looks like electrically. There’s a single wire going up the tree and a network of ‘radials’ buried in the ground below it.
It’s not fabulous like the one above, and I certainly don’t ‘hear’ what hams around me can, but it works for me. I love the fact that I can have fun with my hobby and nobody knows I’m here….
And part of the fun of the hobby is working within your limitations — finding out what you can do with what you have available. I always get a kick out of making a contact with 100 watts and my simple antenna system while others are using 1.5Kw and 3-element beams on top of 70 foot towers!!! It’s just fun to see what you can do. And it definitely hones your communications skill set to compete with the ‘big boys’.
So that’s all for this session. My intent was to give you some ideas and encouragement. As always, the goal is to get you ‘on the air’ and welcome you into the community. We all LOVE helping each other out and exploring new ways to communicate. Please, Please take advantage…
73 Don VE7ATJ