Shortwave Radio Bands?

Question

I am new to shortwave radios, and I'm curious as to how bands works. I believe I have the basic idea, but I'm wondering when I'm doing an automatic scan, does the the band change on its own as the frequencies change? For instance, if I start out on the 75m band, and the radio continues to scan, does it automatically kick it in into the 60m band when it reaches 4700 khz.? Also when I switch over to SSB it goes through all of the frequencies, from 2300 to 26150, so is it operating on an entirely different system? I'm beginning to understand, but it just hasn't quite clicked for me, I may be over thinking it.

Answer 1

Hi there



The automatic scan function on portable shortwave sets rarely work well.

This is due to the fact that background noise on HF (high frequencies) can vary greatly , and signal strength of stations too can vary greatly.



The idea for scanning or auto-tuning come from scanner designs.

It works well for that type of radio , but it blows for SW listening.



That is why proper communications receivers do not have scan functions.

So I advise you to forget about that useless feature and tune manually.



The 'm' band , or 'meter band' is simply another way to express frequency.

So as to maximise the use of the HF spectrum all licensed radio transmitters are restricted to operate in allocated portions of bands.



So when you hear a SW broadcaster say that he is in the 49 meter band , you can realise that at that time he is in the section allocated for International broadcasters called the 49 meter band.



In this example 49 meters could mean any frequency between 5900 – 6200 kHz.

The different allocated bands have different numbers , and therefore different frequency ranges.



Typically , frequencies that are in the lower portion of SW , say below 7Mhz are of limited range night time bands.

7MHz to 12Mhz is medium to long distances and may be open during both day and night times depending upon location.



Between 12MHz and 21MHz are daytime bands and these provide good long distance reception.

Above 21MHz you wont find much SW activity and the range drops down.



In the gaps between the international SW broadcast bands you will find Radio amateurs , ,but you will need to use SSB mode to resolve those signals.

Answer 2

Commercial stations on the shortwave bands such as the 16m through 49m bands all use AM, amplitude modulation. Amateur Radio transmissions in the WARC amateur bands 160m through 10m use SSB and CW. There are other out-of-band services (such as trans-oceanic aircraft communications) which use either AM or SSB.



How the receiver scans is a function of the the receiver internals and without knowing which receiver you have it's difficult to advise you, apart from being trite and telling you to read the instructions which you probably have. Anyways it's more fun to manual tune as an auto tune can easily miss weak but interesting signals.

Answer 3

when doing an automatic scan, you need to have the aerial out / or connected to a long wire out the window to pick up signals.

the radio doing its scan will stop on a strong station. and you will have to restart to get to the next station.

It is far better not to use the automatic scan and tune manually with the knob or buttons marked up & down, find out the frequency of a broadcaster by books or searching the internet.

there are lots of stations in the 13 and 15 metre bands, look there first. or enter 11. 300 mhz and tune up and down from there,

its like fishing in the sea, you never know what you will catch !