Basic HF Comms Setup.....

Any thoughts on the Kenwood TH78A ? There's a guy at work that has one and offered it to me for $150. I'm pretty sure it's "hand-held" size, so hooking it up to the computer may not be an option (?) [I know that Bing/Google should be my friend here :^]

Also, I have another friend that is going to start studying for his Tech - I'm going to "re-study" it myself because I've never actually used it (yet).

 

What is recommended for a base unit, and what is the preferred band...as in meters...so many bands how does one know what to choose and what the most common one would be? It's not like CB, where you have 23-40-120 channels, but all are in one place...with radios ( that I knew of) you had to choose one based on the 10-whatever meter range....Now as I understand it, the newer radios have most if not all the frequencies and no longer a need for separate ones for different bands? Now what about the antennas? Just use a tuner to adjust for each band? It's well above and beyond me...I have the 10 meter radios and the CB's, but I'm not sure what the heck I'll need to have IF/when the time comes....HELP!???

 

just about all modern commercial ham rigs are multiband, 160m to 10m high frequency (shortwave), usually with 6m VHF, and sometimes with 2m (VHF) and 70cm (UHF) all in the same box.

You COULD have just one band (it would simplify your antenna), but the point of all this is, depending on the condition of the season, the sunspot cycle, the time of day, etc., and where you're trying to talk to, the band you want to use is going to be different.

There are single band (heck, even single FREQ) homebrew and kit radios. You could try something like that real cheap. It's not going to be a very high likelihood of success compared to a "real" radio with multi bands and 100w output.

I've got an old (1980, among the earliest solid state [no tubes] radios) Cubic Astro 102BXA that was made before we got the WARC bands so it doesn't work on those (60m, 30m, 17m, 12m). I paid $200 for it at a local hamfest. I got a used 36A power supply for it for about $100. This would be a good basic rig for a beginner. There are several Kenwood, Yaesu, etc. radios that are so similar in capabilities and price as to be interchangeable- each will have their fans, but any of them would work fine. They're not going to interface with a computer or have "menus", they have knobs and switches and buttons. It might be possible to interface a TNC or sound card interface for digital modes but that's not what these radios are best for.

If you want to do digital (and if you don't run across the older radios or have somebody to help you decide if it's a good choice) then it's better to get a more modern radio, for example the Icom IC-706 series. I got one of the last versions, the IC-706MkIIg, which contains ALL of the bands included in all the modern radios- 160m, 80m, (not 60m without modification, normal for the time this radio was popular), 40m, 30m, 17m, 15m, 12m, and 10m on HF; 6m and 2m on VHF; (not 1.25m, that's hardly ever included in multiband radios except a couple of handheld VHF/UHF rigs) 70cm on UHF. There are higher bands but again, they're hardly ever included in such radios. You pretty much need a dedicated radio for those, or some radios (I think the Kenwood TS-2000 does) will accept add on modules for some of them.

2m and higher are always going to be reliable only at line-of-sight. They can be used for special purposes like satellite, metor scatter, or moonbounce; and sometimes the atmosphere will open some mysterious path that will allow comms over the horizon to specific areas, but you can't plan on that. Chasing it for fun, sure, but if you need comms that's not predictable.

Now there's nothing in the laws that says just because you have a multiband radio that is capable of 100w output, that you must have antennas for all those, or that you must transmit full power. Put up a 20m dipole with coax and use it only on 20m, and you don't need a tuner yet. And it will allow some receive capability on all bands, the only trouble could be if you tried to transmit outside the band. A 20m dipole should be very easy to do, you need 468/14mHz= about 33ft of wire, split in the middle, connect each leg to the coax (one to the shield, one to the center conductor). Get it high enough nobody will accidentally touch it, and you're on the air, if not at the greatest efficiency.

You can add to this later for other bands. You can use a longer antenna on a shorter freq if you use a tuner. This will not work as well with coax, it's a lot better if you use ladder line or some other balanced line (two conductors separated by spacers, rather than one inside the other as coax is).

As mentioned, you can use a longer antenna on certain shorter bands without a tuner. I believe a 40m works on 15m in that fashion, but I'm not sure about that.

Since we're discussing a hobby here, you should be aware that you're not going to get everything you need to know in a forum post, it's going to take doing it to start getting a feel for this stuff. I think it's foolhardy to think you can download some stuff and buy "a radio" to stuff in the bottom of the closet, and think that 'someday' when there's no support and you need it in a hurry that you would be able to figure it out. I don't even see why anybody would WANT to try that, since the hobby is a fun one.

 

A little more money, but take a look at the Yaesu FT897. You can use it as a base with a power supply or portable with a car battery or even backpack with an internal battery. Use 2 meters for local stations, 40meters for 50-1000 miles and 20meters for the long haul. You can get the LDG tuner and a simple wire antenna could meet all your needs.

 

Wow, lots of info, now all I need to do is some serious homework!
The radios I currently have are the Rad Sahk's models, HTX-100's..
Only 25 watts, or 5 on CW. I chose them to use as I wanted to keep things as simple as I could, and they would work on my 11meter (cb) antennas....
Is that correct? I also have the larger style of "discone" scanner antennas that allow up to 2,000 watts input to them....
Now I'd prefer to get a newer type of radio that will allow me to listen to and Tx on other freq's....

 

an 80m vertical dipole? Why bother? If you've got room for that you're better off with a beam?

Wire dipoles are horizontal, unless otherwise specified, due to their length. Hanging a long dipole vertically is out of the reach of most hams.

And if it's not high enough to be a half wave then it's more omni than directional, so put it where the trees are and don't worry about the direction unless you have a problem.

 

any shortwave receiver will hear all these bands plus the commercial stuff in between. If you want to listen to hams you need a switch for sideband.

Just about all ham multiband transcievers have "general coverage" receivers that will hear even where they can't talk.

 

I have a vertical antenna and also a Carolina Windom which radiates on both polarities. As the radiator patterns are pretty much omnidirectional their compass orientation isn't important.

The physical length of an antenna is for us humans; the radio is interested in the antenna's electrical length. Using a variety of techniques; we can "trick" the radio for example an 80 meter Hamstick is 7' long.
Lakeview Company manufacturers of Mobile Antennas and Accessories By WD4BUM.The Ham Stick Folks.
Here the trick is coiled wire wrapped around a form. Another "trick" is called a trap.
Can you describe how a trap dipole works?

Traps and other methods electrically trick the radio into believing the antenna is 234/f or 468/f long. Sounds good except nothing is free and here the cost is reduced bandwidth. It may be as little as 40-100 kHz or even less. As the 80 Meter band is 3.5 to 4.0 MHz; 40-100 kHz isn't much.

That was a broad spectrum question; I hope I didn't muddle the answer too badly.

 

I don't even want to pretend to know what I'm talking about, but for some reason I'm thinking I remember somewhere reading that only certain harmonics work well... I vaguely remember odd harmonics being okay, while even (like half, as you would have trying to use a 40m antenna for 20m) would be the opposite of okay... am I daydreaming? The whole worry goes out the window of course if you're using balanced line and a tuner, I'm concerned about giving somebody the impression they can use coax and no tuner when that would not actually be okay... and again I'm pulling this out of the fluff, confirm any of it before you try to use it

 

Windoms, End fed Zepps and others operate on harmonics; depending on impedance a (4:1, 6:1, 9:1 etc) balun is required.

Windom Antenna Home Page, and Handbook

IMO, a good tuner and a great RF ground are required.That means I've always needed a good tuner and RF ground to get multi band antennas to work..

 

You're going to want multi-band capabilities, because the atmospheric conditions are going to dictate what band you're on (that is, if you want to take advantage of any sort of propagation when the bands open up). Even if you're just operating locally on an NVIS antenna, that's most likely going to be either 40 or 80 meters depending on the atmospheric conditions.

There are beacon stations on the different bands that you can tune into to see what bands are open at a given moment.

You might want to look into multi-band rigs for general purpose use.

It might be worth looking into soldering up a couple of Rockmite radios, which you can fit into mint tins and run off of AA batteries. You can use a long length of wire, suspended a couple of feet above the ground as an antenna. It wins all kinds of points for portability, but you're going to need to know Morse Code to use them.

Ham radios require a bit of knowledge to put to use. Don't just run out and buy one. If you try transmitting on one without knowing what you're doing, you can fry the finals in your radio (not to mention, without the license it's illegal unless it's a life-or-death situation). Yes, there is a learning curve. But it'll start to make a lot more sense why we have to have so many bands so far apart from one another.