Meteor Scatter Of VHF Signals 2

Meteor scatter, as we have seen, is an interesting and unusual propagation mode.

The obvious way to get started is to pick a frequency and listen until you hear a 'ping', as explained in the last post. However a little more thought will make the who process easier and more productive.

In case you need it, a link to the last post is below.

http://taperell.blogspot.com/2009/06/meteor-scatter-of-vhf-signals.html

Making a start
First, you need to decide what range of frequencies you want to listen to and then find a station that is between 750 and 1000km from your location.

This is far enough away not to be receivable by ground mode but not so far away that it won't reflect back to your location from the trail.

Band 1 - TV
You can choose the Band 1 television frequencies which are clustered just above and below the 50mHz (6 metre) amateur radio band.

A search for 'band 1 television' will give you several links to frequencies. After that you need a map to check out the location of the station and the distance from your home.

Remember that analogue TV is on the way out so make sure, as best you can, that the station you choose is still broadcasting.

Band 2 - FM
The 88 to 108MHz range is also extremely suitable (as are the OIRT frequencies mentioned in the last post) so look for a station in this band that you will be able to hear clearly at around the same distance.

A major problem is finding a station that will not be swamped by the other local FM stations and this will depend on your own location. I live in a big city which is in a fairly densely populated area so the only 'free' spaces on the FM dial are at the top and bottom of the band. However, if you live away from populated areas then you have more choice.

Amateur radio
The 6m band is best but you can also get meteor scatter on the 2m band and the 4m band.

One range of easy targets are the beacons that transmit around 50MHz (6m). There are several of these in most countries and a search for '6m beacons' will reveal some lists to refer to.

Meteor showers
Meteors can appear at any time since there is an abundance of microscopic matter adrift in space but to increase your chance of success you can wait for a shower to arrive.

Meteor showers are the remains of comets and the like that have previously broken up and which now exist in large clouds out in space.

The Earth encounters them regularly each year at the same time and, as it moves through them, so the incidence of meteor 'strikes' increase dramatically.

A search for 'meteor showers' on the internet will reveal precise details and dates along with the names of the showers.

To use the information, look for the range of dates when the display is expected and then, within that range, the periods when the display is at its maximum.

The days of maximum intensity should give you the best chance to hear the station you have selected.

Where to find out more
The whole subject of meteor scatter is quite a technical one but it is a branch of the hobby that is well supported and quite popular. Search for 'meteor scatter' on the internet and read some of the results found for more information.

There are also various books on sale that deal with VHF propagation that will often have a whole section on meteor scatter. For example, refer to the books sold by the Radio Society of Great Britain

However, probably the most fun introduction to the subject is to search on YouTube for 'meteor scatter' and then just sit back and watch.

We have dealt with the radio but next week we will look at the antenna and also talk about an interesting way to 'see' meteor pings.