Is the HF Band a Noise Wasteland?

CB uses the top end of HF. It is near useless during daylight hours for days at a time when the ionosphere is highly charged and signals from hundreds of miles away blot out the person a few miles away that you actually want to talk to. The unreliabilty makes it undesirable for radio communications of any importance.

The radio hams and CB are on HF because back when the bands where allocated UHF was expensive and impractical due the limitations of the available technolody. No, nobdy thought "put the junk here", they made frequency allocations based on practicality.

These days money seems to be the main driving factor. In Europe short range license-exempt digital-modulation walkie talkies are being allowed. I'v read they have about a 7dB advantage over FM. There is no technical reason to not allow full duplex operation or automatic frequency selection to minise clashing with other users. The cynic in me says that the billions the mobile phone companys paid for licenses has somthing to do with it.

Bob

Bob

Dont forget Shortwave broadcasts, and Land and Marine commercial SSB comms, military nets, time and weather signals...lots!

why would you want to wait for the sun spots to go away? it's better with them..

It always was. Stuff below 50 MHz gets reflected by the ionosphere, so at HF frequencies the whole world is in one noisy tin can. Natural atmospheric noise, lightning and such, is trapped too. That's why it's not worth designing an HF receiver with an especially good noise figure.

John

I'm not familiar with sun spot effects on HF radio. I just thought. Sunspots>ionized particles>solar wind>trapped in earth mag field>charged particles in atmosphere>noise in HF band Plus some nice colours in the sky..

Are you saying that during sun spots it's more uhhh...say 'excusable'... to make EMI (radiated smps EMI) in the HF band?

D from BC British Columbia Canada.

Thank god for noise blanker circuits....

Speaking of spectrum wastelands.... the petition to reallocate TV Channel-6 to the FM band is back on the horizon. This time to include TV-5 as well. (USA)

It would add substantially to the FM broadcast band, which is congested in most urban areas. And very few TV stations have elected 5/6 as their terrestrial DTV channel. Perhaps the time has finally come?

-mpm

Do we need 15 more soft rock stations, or three more places to hear Prarie Home Companion?

John

If you must live with small antennas you have to. One reason my EMC kit has a LNA.

And we all by new car radios? Nah.

Could use a few more country stations with the old stuff. And I want Wolfman Jack back!

The band is used by more than that. Yes we amateurs use from the 160m band up to the 2m band and then into the cm range. CB operators are strictly 11m which runs form 26.965MHz to 27.405MHz while the amateur

Yes, we amateurs do use the internet, but we also use the radio.

Simple, the E layer of the atmosphere gets all charged up from that particle bombardment. That makes it reflect radio signals in the HF bands. You get increased distance.

Now temperature inversions will duct VHF signals to distant locations.

Get your amateur radio license. You might learn a thing or two.

No but we could use more community based stations and non Clear Channel stations.

Ahhh... So in that case.. I should have wrote: "Who wants to wait for lots of sunspots?"

Amateur radio...psshhht :P 'Can you hear me .zzshhhht..Can you hear me...zsshhhtt..what?.zsszzhhhst..Repeat that ,,,,zssshhhts' Bad enough I get that sort of frustration from my cellphone.

D from BC British Columbia Canada.

Then one fine day there is a major power outage, the cell tower backups runs dry and everyone in the area finds zero bars on their cell phone. That is where point to point communication can save the day, and has many times.

Real amateurs use CW. That tends to get through static, plus we also use phonetics on the voice bands for those difficult to hear contacts.

I will agree that cell phones sounds like sideband radio to me.

Exactly. There have been numerous instances where amateur radio has stepped in to save the day.

Even now in the 21st century if your power goes out for more than 4 to 8 hours you'll lose most cell service. Another 20 or so hours from that phone service goes.

More than that? I'm thinkn if the HF band is not used for emergencies, it can be buzzed with radiated smps noise.

D from BC British Columbia Canada.

I think if anyone is serious about communication during a disaster, they would have a satellite phone (ex:Iridium Motorola 9505) and a solar charging system. Unfortunately that's >>$1000.00

D from BC British Columbia Canada.

You old fart@!

Sure that might happen but you need to coordinate police and fire too.