Posted by austinallegro 17 hours ago
(Not sure how 1750m LowFER would be handled; maybe just keep it on as an unlicensed exception?)
It appears that the west has decided to leave those air bands to foreign influences. Those propaganda stations also do not appear to care much wether a band is deemed an amateur band in your country or not.
I would sincerely hope so too. Moreover, if or when the BBC closes its longwave service it'll bring serious pressure on the few remaining countries to close their LW services.
With the abandonment of the LW Service the Band will be up for grabs and there will be pressure on WRC/ITU to reallocate the spectrum. My guess is that's likely happening already but these days I'm not close enough to the ground to know. So I'd strongly urge Amateurs everywhere to start campaigning before it's too late.
I'm an ex-amateur but I still strongly believe in the movement and its objectives, and I think that if or when—more likely when—the LW service officially closes (by WRC-set deadline) then the Amateurs should be ready to immediately step in.
No doubt there will be pressure from others (possibility stockbrokers wanting to take advantage of the ionosphere beating fibre in transmission speed around the globe for their ultrafast stock trading), so I'd expect there to be a real bun-fight for this valuable LF spectrum.
Personally, if or when reallocated I'd like this Band to go to scientific research and this is where amateurs could step in to help, here they'd share the Band with scientific researchers. One such example which I've raised on HN before is earthquake prediction. It's already known that in many instances that before earthquakes ocurr the crystalline rock structure is under such pressure that it can generate piezoelectric fields and these can affect the height of ionosphere and in turn the distance it reflects RF transmissions will change. This effect is most noticeable at very low frequencies and can be detected.
A network of stations would be needed around the world to monitor these frequencies constantly and the Amateur Service could provide this.
There are other options too. Even though I'm no longer involved in Amateur Radio I'm concernd with its flagging numbers (I suppose once a member of the Amateur fraternity always a member). As an alternative to the BBC's closure, I even see ways for the Amateur Service to make money, perhaps Amateurs could not only mod the BBC's transmitters but do so a at vastly reduced cost then actually run the stations at reduced cost (see my other post to this story). The BBC could justify this unorthodox approach on both maintenance and running costs and that the LW Service is now less important given the low number of listeners (maintaining the uptime percentage would be less important, etc.).
BTW, I expressed my concern about the Amateur Service's flagging numbers on HN only yesterday: https://news.ycombinator.com/item?id=41949118
Marconi T or L antennas with capacitance hats and loading coils are well within amateur practice on 630m[1] and 2200m, and common from 40m/7MHz on down.
Not very efficient still; an ERP of 1W, as demanded by the 2200m band, can still take a lot of power on a less-than-ideal antenna. Similar story for 630m. (160m and up is usually not so bad, just that even a good Marconi on longwave is still too big for most people.)
But the current LowFER[3] regs limit the transmitter to 1W final stage input power, and a COMBINED feedline and antenna length of 15m. At least allowing amateurs to operate more here would allow more than just extremely low SNR modes like WSPR to be used at any real distance.
[1]https://www.hamsignal.com/blog/dog-days-and-the-marconi-t-an...
and https://vk6ysf.com/t_antenna_arrangment.htm
[2]https://en.wikipedia.org/wiki/2200-meter_band#International_...
Now there are none stations that I can listen at night, and I miss it
What a pathetic argument! When you read crap like this you know you're being told sop—an attempt to bamboozle the public with technicalities that don't really exist. Any commonly available high powered RF tetrode from an FM or TV station would do the job albeit with some (mostly mechanical) modifications to the transmitters. Also, it's a common practice to refurbish high power transmitting valves, there are companies that specialize in doing it.
I say that as someone who has been involved with high power broadcasting transmitters, in fact I was involved in building several FM broadcast transmitters from the ground up.
At only 198kHz—which is somewhere between one 1/500th and 1/1500th its normal operating frequency—any high power VHF transmitting tetrode would be just loafing along.
No doubt the way commerce works getting a one-off specialist job to do the conversion would be expensive (I wish I could do it, I'd quote half the price and still make a handsome profit).
If the BBC is so strapped for cash perhaps it could ask the Amateur Radio fraternity to mod the TXes for free as a public service. Then after the mods the service could recommence on half power to save costs.
Also, there are good strategic reasons why this transmitting infrastructure should be kept operational on these low longwave frequencies which I haven't got time to address here.
Suffice to say, I think this proposed closure is more a hatchet job by accountants than from any long-term strategic thinking by governments.
Damn shame governments only seem to listen to nanny goat advisors these days.
Bureaucrats want a quite life, and when threatened with their actual names and positions being published in the press for being obstructive over nothing then they'll cave in. Remember, troublemakers in the public sector aren't usually rewarded with promotions.
:-)
Once-off Broadcast Transmitters need only demonstrate that they meet the relevant standards.
Many of the existing LF and MF BC transmitters were effectively custom built to meet the requirements of their transmit license (for example, the radiation pattern of the antenna were often unique for each station).
I was rather surprised to see an LW band on a regular clock-radio when I visited the UK, though that was 25 years ago.
https://www.nps.gov/pore/planyourvisit/kph_treetunnel.htm
KFS still has a transmitter antenna farm in Palo Alto off 101 with a receiver antenna farm in Half Moon Bay.
https://www.radiomarine.org/historic-coast-stations/kfs-san-...
https://coastview.org/2024/01/28/kfs-high-frequency-receiver...
The WWVB time signal is technically inside the longwave band, at 60kHz.
> During the time following a perceived attack, a series of progressive checks are made by submarine crews leading up to the captain opening the letter. These include trying to listen for radio transmissions from various levels of Royal Navy and Ministry of Defense command using multiple methods, and most famous of all, listening for new radio broadcasts by BBC Radio channel four, and specifically new episodes of BBC Today. […]
* https://www.twz.com/7300/letters-of-last-resort-are-post-apo...
Also:
I'm not privy to the accuracy of that but it makes sense given the low frequency. In my earlier post to this story, that comes under the umbrella of what I said about that there were strategic reasons for not shutting down the LW Service and governments having nanny goats for advisors.
As well as tbese low frequencies being better to communicate with submarines—although frequencies ten times lower (~18kHz) are much better—they travel long distances and can be very reliable over their given service areas (the ionosphere being more predictable at these low frequencies).
Other reasons are that LW would provide more reliable communications during emergencies such as a mass communication outage with say the internet and other comms services being out. This could happen during nuclear war with EMP destroying much of the electronic infrastructure, similarly a repeat of the 1859 Carrington Event would deviate most existing communications infrastructure. It's dead easy to radiation-harden a LF transmitter if it used only valves (it's halfway there now as its RF output stage already uses valves).
[2] https://blackdiamondfm.com/programmes/wee-scone-variety-show
However "Longwave and Mediumwave Broadcast" unambiguously refers to that service.
It doesn't: There's a lot of non-AM/non-voice stuff on longwave, most notably various digital time beacons (WWVB in the US, DCF77 in Western Europe etc.)
I have noticed that regular medium-wave AM seems to have decent propagation (though maybe not many thousands of miles) and also improves at night.