These days, there's a ridiculous number of directions one can take in the hobby of amateur radio. But in the beginning, "amateur radio" meant someone banging out Morse Code on medium wave or shortwave.
Shortwave (HF) is the bread and butter of amateur radio. Before there were satellites, before transoceanic cables, people were using HF radios to communicate across the world. And they still do, since HF signals can get from their source to their destination without any equipment in between.
The main drawback is that the propagation of HF radio waves around the world is heavily dependent on atmospheric conditions. And this is where the challenge lies.
Since shortly after I got my license, I've been wanting to play with HF. I scored well enough that my license permits transmission on all the amateur bands. However, an HF rig isn't cheap. I'd need at least a few hundred dollars for a basic used rig, and with everything else that's going on right now, that just isn't in the cards.
Enter the community. My situation came up in passing during a discussion over our weekly lunch meeting, and a fellow operator was more than happy to loan me one of his old rigs that had been languishing in his basement for some years. The following week, I helped him lug a Kenwood TS-530S and an AT-230 antenna tuner from his pickup to mine.
The tuner is especially important to my situation, and I'll get to it in a moment, but first I want to yak about the radio itself. Kenwood built these radios throughout the 1980s (I can't find a date stamp on my particular unit so I don't know when exactly it was manufactured.) They're what's called a hybrid rig, meaning that most of the electronics are solid state, but it uses vacuum tubes rather than transistors for the final RF amplifier (the part that puts the power out to the antenna).
Vacuum tubes have been largely replaced by transistors, even in ham radio, because they don't consume as much power, are smaller, and last longer (tubes have a lifespan, much like light bulbs, and radios using tubes are designed so that the tubes can be easily replaced.) However, tubes still find their uses in large RF power amplifiers, microwave ovens, audiophile amplifiers, etc.
The Kenwood hybrids are sought after among the ham community. (As an example, I recently found an eBay listing for a TS-530S selling for $300CAD - and it's broken.) While they're a simple rig, lacking many of the features in modern digital radios, they make up for it by being easy to use, robust, and easy to repair. The radio's much larger and heavier than a modern radio of equivalent functionality, but large discrete components are easier to remove and replace if something goes wrong.
It's actually a perfect starter rig for a ham just getting into HF.
For starters, it doesn't feel like a toy. I had an opportunity to use an Elecraft KX3 recently, and it wasn't much bigger than my handheld. The Kenwood lets you know that it means business. It's twenty kilos of radio sitting on my desk.
The other thing that makes it perfect for a starting ham is that it's all manual. The most modern thing about this rig is the digital frequency readout. There's no automatic antenna tuner, and you have to tune the final amplifier stage whenever you switch frequency bands. Having to learn about all this stuff teaches you things about how radios are built, and how signals propagate through your antenna and through the air. Things that you won't learn on a modern rig like an Elecraft K3. Don't get me wrong; I'd love to have a K3 in my shack, but it's like giving a calculator to a fourth-grader before teaching them long division. There's always the risk that they'll take the easy way out, and miss an important learning opportunity.
And learning is the reason that I got into ham radio in the first place.
Of course, this radio isn't without its drawbacks. For me, the biggest one is the lack of portability. Between being physically large and heavy, and being power-hungry, this rig isn't going camping with me. My goal of contacting hams on the other side of the world while sitting next to a campfire by a lake in the bush will have to wait until I can afford a smaller rig like the Yaesu 817D or an Elecraft KX3. However, for now, that's more than made up for by the fact that I'm on the air, with nothing more than a piece of clothes line strung between my house and my shed.
And that's where the tuner comes in. A radio and its antenna each form two halves of a resonant circuit, and to maximize power transfer from one half to the other, each half must have the same impedance. Since the impedance of an antenna is a function of the length of the antenna and the frequency of the signal, (this is an oversimplification, but it works for my purposes,) antennas have to be constructed with the proper length and spacing in order to work. Any random length of wire usually won't do, because it will be too long or too short, and this will cause RF energy to be reflected back to the radio. This reflected RF energy gets turned into heat in the radio's final stage, which eventually burns it out.
The tuner makes up for a badly tuned antenna by adding additional resistance or reactance to the antenna side of the resonant circuit so that it appears to be perfectly matched to the radio. This allows the radio to push maximum power to the antenna without risking damage. The drawback is that, since the antenna isn't truly resonant, some amount of transmitted power is soaked up by the tuner. The further out of tune the antenna is, the more power is wasted.
The silver lining of this cloud is that a tuner allows an operator to use any random length of wire as an antenna. It's not as efficient as a tuned antenna, but it gets my signal out into the air without risking letting the magic smoke out of my borrowed tubes. Twenty bucks worth of clothes line and a couple screw-in anchors has me talking to folks a few hundred kilometers away.
The tuner is especially important to my situation, and I'll get to it in a moment, but first I want to yak about the radio itself. Kenwood built these radios throughout the 1980s (I can't find a date stamp on my particular unit so I don't know when exactly it was manufactured.) They're what's called a hybrid rig, meaning that most of the electronics are solid state, but it uses vacuum tubes rather than transistors for the final RF amplifier (the part that puts the power out to the antenna).
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| Kenwood hybrid final compartment. Photo courtesy of k4eaa.com |
The Kenwood hybrids are sought after among the ham community. (As an example, I recently found an eBay listing for a TS-530S selling for $300CAD - and it's broken.) While they're a simple rig, lacking many of the features in modern digital radios, they make up for it by being easy to use, robust, and easy to repair. The radio's much larger and heavier than a modern radio of equivalent functionality, but large discrete components are easier to remove and replace if something goes wrong.
It's actually a perfect starter rig for a ham just getting into HF.
For starters, it doesn't feel like a toy. I had an opportunity to use an Elecraft KX3 recently, and it wasn't much bigger than my handheld. The Kenwood lets you know that it means business. It's twenty kilos of radio sitting on my desk.
The other thing that makes it perfect for a starting ham is that it's all manual. The most modern thing about this rig is the digital frequency readout. There's no automatic antenna tuner, and you have to tune the final amplifier stage whenever you switch frequency bands. Having to learn about all this stuff teaches you things about how radios are built, and how signals propagate through your antenna and through the air. Things that you won't learn on a modern rig like an Elecraft K3. Don't get me wrong; I'd love to have a K3 in my shack, but it's like giving a calculator to a fourth-grader before teaching them long division. There's always the risk that they'll take the easy way out, and miss an important learning opportunity.
And learning is the reason that I got into ham radio in the first place.
Of course, this radio isn't without its drawbacks. For me, the biggest one is the lack of portability. Between being physically large and heavy, and being power-hungry, this rig isn't going camping with me. My goal of contacting hams on the other side of the world while sitting next to a campfire by a lake in the bush will have to wait until I can afford a smaller rig like the Yaesu 817D or an Elecraft KX3. However, for now, that's more than made up for by the fact that I'm on the air, with nothing more than a piece of clothes line strung between my house and my shed.
And that's where the tuner comes in. A radio and its antenna each form two halves of a resonant circuit, and to maximize power transfer from one half to the other, each half must have the same impedance. Since the impedance of an antenna is a function of the length of the antenna and the frequency of the signal, (this is an oversimplification, but it works for my purposes,) antennas have to be constructed with the proper length and spacing in order to work. Any random length of wire usually won't do, because it will be too long or too short, and this will cause RF energy to be reflected back to the radio. This reflected RF energy gets turned into heat in the radio's final stage, which eventually burns it out.
The tuner makes up for a badly tuned antenna by adding additional resistance or reactance to the antenna side of the resonant circuit so that it appears to be perfectly matched to the radio. This allows the radio to push maximum power to the antenna without risking damage. The drawback is that, since the antenna isn't truly resonant, some amount of transmitted power is soaked up by the tuner. The further out of tune the antenna is, the more power is wasted.
The silver lining of this cloud is that a tuner allows an operator to use any random length of wire as an antenna. It's not as efficient as a tuned antenna, but it gets my signal out into the air without risking letting the magic smoke out of my borrowed tubes. Twenty bucks worth of clothes line and a couple screw-in anchors has me talking to folks a few hundred kilometers away.
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