If you have looked around this site, you may have noticed we have been more than a bit concerned about the future of shortwave. All our favourite stations are gone now, our only regular listen is the excellent World Of Radio and, dare we say this, we get the podcast rather than warm up the wireless.
Then the snows came. Might as well have a listen around. It's what we did back then when our knowledge of receiver design was knowing where to find the output valve. A 6V6G was the hottest in the set so you put your tea on the cabinet above it. It kept your tea warm.
Tea. We start our day with it, that time near dawn when the real long-distance stuff comes in on the grey-line. WWV ticks away on 5000, fluttery and distant, broadcasting time and frequency information from Fort Collins, Colorado. The time announcements seem hypnotic and reassuring. If we can hear them, the band is open. So what else is out there?
All India Radio on 5040 with a barrelling phase distortion that says it has come a long way so treat it like a guest. 5070 is the old standby WWCR from Nashville, starting to fade now as daylight comes in and the tea runs out.
Other folk are wondering what 5 Megs will do. We tune between 5258.5 and 5406.5 to make sure we take in the eleven sub-bands radio amateurs can now use. Bad weather and propagation conditions are the perfect mix for ham conversation. Add to that the welcome return of AM and we are back to 80m in the 1960s.
5403.5 is a good place to start. The band has the military as the primary user, so listen for scared hams when the lads call back and nervy CCF types wondering if the local ham is one of us.
Air Traffic Control is a good listen. Once clear of the airport, aircraft use 5616 and 5649 to see them safely across the sea. There are many ATC channels at 5MHz so listen around for mentions of secondary frequencies and tune in. All ATC frequencies are shared around the world, so listen for ATC DX. We wonder if pilots do.
Coffee. The snow has set in and the skies are dark. We keep a good old-fashioned filament bulb in the elderly Anglepoise lamp that lights these notes, the low-energy CFL bulbs are high on interference at 60m. So are the local TVs and internet hubs. Another reason for listening less?
On 5450, RAF Volmet says it's snowing too. This is good to know and rather important as this is a weather service for pilots. Here on the ground it's great for setting barometers, just listen for the QNH announcement. Up on 5505, Shannon Volmet serves the commercial sector. If you are near one of the listed airports, the one-word weather forecast is all you need.
Lunch. A rushed affair as for some reason the listening bug has got us again and we need to be by the radio. Back then, our war-surplus wireless had about twenty glowing valves in it, making a hot-plate of the set top. Lunch never went cold.
Peppered all over 60m are Number Stations. We don't think we are breaking anybody's cover if we say we heard them on 5301, 5630 and 5745 today as these Spy Stations pass on 5-figure groups to agents in the field. What they do with them we cannot say as the decode is issued once then destroyed. Going back to the Cold War, it remains a very secure way of passing information. More so than the internet.
When the weather is bad, we like to keep watch on 5680, the home of Kinloss Rescue. From here they coordinate Search And Rescue services to people who really should not be out on a day like this. We listen for POBs, the number of Persons On Board after an operation, then we know they are getting the help they need. They used to be SOBs, the number of Souls On Board but they must have recruited American pilots as SOB means something else over there. It must still ring true when called out to rescue a badly equipped climber.
More tea, even a biscuit or two. Above 5780, we head for the 49m Band. There is still the odd out-of-band broadcaster to hold your interest, alone and in the clear but as evening creeps in and the band comes alive, we notice the gaps. No more BBC World Service on 5975 but the odd relay can be heard when conditions are right. Don't get too excited, they are being closed too.
We miss Radio Canada International on 5995, the Netherlands on 5955 but that was then and this is now. We have spent a day on 5 Megahertz and did not notice the time pass. It's dark and time to pull the Big Switch.
A brandy to celebrate our radio day? The toast is Absent Friends...
One reason for seeking spectrum around 5 MHz is to provide an alternative to 3.5 MHz and 7 MHz for single-hop contacts especially during sunspot minima years.
|Lower Limit kHz||Upper Limit kHz||Notes on Current Usage|
|5258.5||5264.0||CW activity. 5258.5 kHz international use|
|5276.0||5284.0||USB dial frequency 5278.5 kHz international use|
|5288.5||5292.0||Experimental beacons on 5290 kHz|
|5298.0||5307.0||All modes, highest USB dial frequency 5304 kHz|
|5313.0||5323.0||All modes, highest USB dial frequency 5320 kHz|
|5333.0||5338.0||Highest USB dial frequency 5335 kHz|
|5354.0||5358.0||Highest USB dial frequency 5355 kHz|
|5362.0||5374.5||Digital modes activity. Highest USB dial frequency 5371.5 kHz. International use.|
|5378.0||5382.0||Highest USB dial frequency 5379 kHz|
|5395.0||5401.5||Highest USB dial frequency 5398.5 kHz|
|5403.5||5406.5||USB dial frequency 5403.5 kHz international use|
The entire signal must stay within the limits of the frequency segment. On USB, the transmitted signal will start from the dial frequency or suppressed carrier frequency and extend up to 3 kHz above the dial frequency. For example, an operator wishes to select an SSB frequency in the 5333 - 5338 kHz segment. The highest dial frequency that can be used is 5335 kHz as this will result in the signal occupying the range from 5335 kHz to 5338 kHz. 5333 kHz would also be an acceptable dial frequency as the transmitted spectrum would still be within in the segment limits, this time occupying the range 5333 kHz to 5336 kHz.
In another example, at 5403.5 kHz the segment is only 3kHz wide and extends from 5403.5 kHz to 5406.5 kHz, therefore the only frequency that can be used is setting the dial to exactly 5403.5 kHz. Anything higher or lower will result in the transmitted signal being out of band. The highest USB dial setting for each segment is shown in the table for reference.
Propagation on the 5 MHz band is very different to our other bands, offering excellent UK coverage during daylight hours with very simple antennas and low power. At night, the band can offer plenty of DX with activity from the US and further.