HF antenna decisions

[xf8u39]

Guys,
I am looking to start out soon with an SDR dongle (for now) and start monitoring HF
Now, I thought about using a standard CB antenna mounted on my rooftop. I've done some digging on these antennas and they will quite happily receive HF from 3 to 30MHz

However, when it comes to transmitting it's a different story. I believe I will need some kind of ATU to avoid frying the dongle.

Question is: is a CB antenna the best option for RX and TX?
I have the space, but I don't really want to be fiddling around with very long wires in my garden hooked up to a tree etc.

Rds
Michael.

 

[Token]

Guys,
I am looking to start out soon with an SDR dongle (for now) and start monitoring HF
Now, I thought about using a standard CB antenna mounted on my rooftop. I've done some digging on these antennas and they will quite happily receive HF from 3 to 30MHz

And a coat hanger will also happily receive HF ... that does not mean it will do it well. The same with a CB antenna, it will kind of work to receive 3 - 30 MHz, but it is not going to do it well. You can absolutely use it, until you get frustrated by the poor performance.

However, when it comes to transmitting it's a different story. I believe I will need some kind of ATU to avoid frying the dongle.

Question is: is a CB antenna the best option for RX and TX?

What SDR dongle transmits? And if one does, does it do it at a high enough power level to worry about frying anything?

A CB antenna is the best option for RX and TX in the CB band, or slightly outside it, maybe 10 meters to 12 meters, with some work. Outside that range, you are probably going to have to find a different solution.

I have the space, but I don't really want to be fiddling around with very long wires in my garden hooked up to a tree etc.

Antenna efficiency (especially if talking both RX and TX), at a basic level, is dependent upon the relationship of the wavelength of the signal and the size of the antenna (there are a lot of other variables also, but that is a basic starting point). The HF range has some fairly long wavelengths, from 100 meters to 10 meters. A good antenna is going to be a bit bigger, and especially so if you want to do it for low cost. For the money, very little outperforms a basic, properly built and installed, wire dipole.

Oh, and realistically, no one antenna is going to cover 3 - 30 MHz well for both RX and TX. Sure, you can find one antenna to do it all, but does it do it well? There are a few options out there, but they are all compromises of some kind. A dummy load generally works at frequencies across a wide range, and makes the transmitter very happy.

Wire antennas are easy, they can be cheap, and they can work quite well at HF. It is just a fact, and many (most?) HF listeners get to a basic wire antenna at some point in their listening timeline, once they become dissatisfied by their built in antennas or first "do it cheap and do it small" attempts.

T!

 

[K6GBW]

If you are just receiving a simple wire antenna is a lot easier. Wire can be made to transmit in several ways. I guess the question really is what kind of space do you have? If you have a yard with a tree or something like that then a wire is going to give you more juice for the squeeze. I'd use a vertical antenna only if your interest is strickly the upper HF bands or if you have a restricted amount of space.