Range of HF

[Vaibhav Birit]

With 20m band, and 5W of power and a dipole antenna how much range can i expect
1. for CW
2. for Audio (AM or SSB)

Assuming average band conditions

 

[Nigel Goodwin]

With 20m band, and 5W of power and a dipole antenna how much range can i expect
1. for CW
2. for Audio (AM or SSB)

Assuming average band conditions

As I understand it you can go round the world on 20m, under the right conditions!.

But, like anything else, things vary greatly - and the exact time of day makes a HUGE difference.

Distance is best with CW, SSB comes next, with AM a long way back in third place - simply due to the amounts of power used to carry the information.

 

[atferrari]

Any place around world, in fact

As Nigel points out, it depends of time and conditions, but in 24 hours you should be able to contact very distant places all around the the horizont, so to speak.

In that band as in many other, it's normal practice to work with directional antennas what facilitates to discriminate stations from each other (it used to be a crowded place) and from noise. But you know that.

Given the domestic situation I've always used "long wire" antennas which becomes directional to a certain extent. The wire was, really long, not less than 30+ meters. The same in vessels.

When on board, the course of the vessel decided what would be my "choice" of the day. Installing 20-m directional antennas in vessels was close to a nonsense (cost and time during it would be actually used)

For experienced operators, CW has the added advantage that may be read even buried in noise still being meaningful when voice is already impossible to recognize. Being a narrower band emision helps even more.
And it's somewhat easier to filter to eliminate the interference from other emitters too close in frequency. But seeing the contents of your site, sure you know that much much better than me. :?

Agustín Tomás

Former LU2AKB/MM and LU5DQE/MM (that was nice!).

PD: Try a long wire - It's all fun and SIMPLE! :wink:

 

[stevez]

QRP is used to describe amateur radio operations at 5 watts or less. You might take a look at QRP amateur radio websites for more detail that supports what has already been stated - around the world is possible on 20M at times.

 

[Dean Huster]

I have a ham friend in Oklahoma who bought Radio Shack's little 10m transceiver when it was on sale and used it with a loaded vertical in his car. He routinely contacted folks in Singapore with that 15 watts, punching through past a nearby ham running a full keg. Weird stuff, but he was operating during the peak of the 11-year sunspot cycle, too.

When I informed the kids I was teaching that the 10m ham band is right alongside the 11m CB band and that the 15 watt ham could get around the world while CBers operating illegally with 1000 watts could get out of the state. They didn't understand until I told them that power wasn't the issue -- the number of operators was. There are so may on the CB band at one time that the noise floor is so high that even the powerful signals get drowned out.

Using a CB is like two people at a final four basketball game trying to have a conversation. If they're right next to each other, they can be heard. But if separated by ten people, there's no way. The ham on 10m is like being in that same basketball arena with only 20 people present. Conversation isn't a problem.

Dean

 

[guzzimac]

As stated, 5W will get you everywhere on 20m even at this low point in the sunspot cycle. The thing to concentrate on is the aerial. If you can't manage a beam, which is large and needs to be high up, then you can work wonders with wire aerials. I use a 1.5 wavelength dipole which has slightly more gain than a standard 1/2 wavelength dipole. For dx work it really needs to be a minimum of 0.6 wavelength above ground, otherwise the higher the better for a low take-off angle. Feed impedance is approx. 100ohms so a VSWR of 2:1 or thereabouts - no big deal.

Failing that, investigate verticals. They have a low take-off but do require either a good rf ground system or tuned radials which can be a pain.


Rob.
G4FAX