7 ms·

> What’s the actual point for the license in the first place? The electromagnetic spectrum is a limited resource; an amateur radio license is a license to do c

by kwk1 6y ago

> What’s the actual point for the license in the first place? The electromagnetic spectrum is a limited resource; an amateur radio license is a license to do certain kinds of experiments in the spectrum. The kind of activity that makes up these experiments when done by someone who doesn't know what they're doing has the potential to cause harm which is hugely disproportionate to the amount of effort it would take to do it. While it's possible to pinpoint individual offenders, if unlicensed activity was widespread then the ability to do so would be overwhelmed.

jacquesm 6y ago
In practice though lots of 'HAM's' use their license as an access ticket to a slightly more elitist version of CB radio. The number of people that actually move the needle by doing experiments is dwindling year by year.
- GekkePrutser 6y ago
  Not just more elitist, also a lot more capable of course. With 4W FM on 11m you're not going to make it across the world (unless in exceptional conditions). But I agree this was never the intention of the license.
  - jimktrains2 6y ago
    nitpick: CB is AM or SSB, not FM. Aside: 4W is for AM. You can do a little more (12W iirc) on SSB because it's spread more evenly across the bandwidth being used.
    - GekkePrutser 6y ago
      Ahh I suppose it is in the US. Here in EU it's FM actually. AM and SSB are forbidden. But I know some people import "President" rigs to use it anyway, as the band is hardly policed at all these days.
      - detaro 6y ago
        > AM and SSB are forbidden. Slightly depends on the specific country: in Germany some channels also allow AM and SSB.
      - kefyras 6y ago
        Are there European countries left which don't allow AM or SSB? I know UK was an outlier, but they allow it since 2014.
    - jacquesm 6y ago
      CB = Citizens band, it does not actually prescribe a modulation method unless you want to apply some geographical limitation. Nothing technical stops CB from being FM (in many places it is), and SSB is technically just another (improved) form of AM. The main technical restriction is simply that at the frequencies that CB typically operates at an FM modulation mode would use too much bandwidth. Enter the UHF version of CB which allows for FM modulation.
      - jimktrains2 6y ago
        "Nothing technical stops CB from being FM (in many places it is), and SSB is technically just another (improved) form of AM." No, FM is not allowed, see below. SSB is basically AM with a suppressed carrier. (i.e. In SSB, Frequency deviation is the demodulated frequency, whereas with FM frequency deviation is the demodulated amplitude.) (You're not wrong in calling it improved, I'm just expanding on how for anyone else reading.) FWIW, You're not allowed to broadcast music on CB, but that doesn't stop people either. § 95.971 CBRS emission types. Each CBRS transmitter type must be designed such that its capabilities are in compliance with the emission type rules in this section. (a) Permitted emission types. CBRS transmitter types may transmit only AM voice emission type A3E and SSB voice emission types J3E, R3E, or H3E. (b) SSB requirements. Each CBRS transmitter type that transmits emission type J3E, R3E, or H3E must be capable of transmitting only the upper sideband with suppressed, reduced or full carrier, respectively, but may additionally be capable of transmitting only the lower sideband, with suppressed, reduced or full carrier, respectively. A3E or A3EG -Ordinary amplitude modulation used for low frequency and medium frequency AM broadcasting J3E - SSB speech communication, used on HF bands by marine, aeronautical and amateur users R3E - SSB with reduced carrier (AME) speech communication, primarily used on HF bands by the military (a.k.a. compatible sideband) H3E - AM, single sideband, full carrier But yes, even narrow FM would be too wide at 10-15kHz. § 95.973 CBRS authorized bandwidth. Each CBRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the emission type under test. (a) AM. The authorized bandwidth for emission type A3E is 8 kHz. (b) SSB. The authorized bandwidth for emission types J3E, R3E, and H3E is 4 kHz. "Enter the UHF version of CB which allows for FM modulation." That could be interesting, but would be even more line-of-sight than CB is.

by kwk1 6y ago

jacquesm 6y ago

In practice though lots of 'HAM's' use their license as an access ticket to a slightly more elitist version of CB radio. The number of people that actually move the needle by doing experiments is dwindling year by year.

GekkePrutser 6y ago
Not just more elitist, also a lot more capable of course. With 4W FM on 11m you're not going to make it across the world (unless in exceptional conditions). But I agree this was never the intention of the license.
- jimktrains2 6y ago
  nitpick: CB is AM or SSB, not FM. Aside: 4W is for AM. You can do a little more (12W iirc) on SSB because it's spread more evenly across the bandwidth being used.
  - GekkePrutser 6y ago
    Ahh I suppose it is in the US. Here in EU it's FM actually. AM and SSB are forbidden. But I know some people import "President" rigs to use it anyway, as the band is hardly policed at all these days.
    - detaro 6y ago
      > AM and SSB are forbidden. Slightly depends on the specific country: in Germany some channels also allow AM and SSB.
    - kefyras 6y ago
      Are there European countries left which don't allow AM or SSB? I know UK was an outlier, but they allow it since 2014.
  - jacquesm 6y ago
    CB = Citizens band, it does not actually prescribe a modulation method unless you want to apply some geographical limitation. Nothing technical stops CB from being FM (in many places it is), and SSB is technically just another (improved) form of AM. The main technical restriction is simply that at the frequencies that CB typically operates at an FM modulation mode would use too much bandwidth. Enter the UHF version of CB which allows for FM modulation.
    - jimktrains2 6y ago
      "Nothing technical stops CB from being FM (in many places it is), and SSB is technically just another (improved) form of AM." No, FM is not allowed, see below. SSB is basically AM with a suppressed carrier. (i.e. In SSB, Frequency deviation is the demodulated frequency, whereas with FM frequency deviation is the demodulated amplitude.) (You're not wrong in calling it improved, I'm just expanding on how for anyone else reading.) FWIW, You're not allowed to broadcast music on CB, but that doesn't stop people either. § 95.971 CBRS emission types. Each CBRS transmitter type must be designed such that its capabilities are in compliance with the emission type rules in this section. (a) Permitted emission types. CBRS transmitter types may transmit only AM voice emission type A3E and SSB voice emission types J3E, R3E, or H3E. (b) SSB requirements. Each CBRS transmitter type that transmits emission type J3E, R3E, or H3E must be capable of transmitting only the upper sideband with suppressed, reduced or full carrier, respectively, but may additionally be capable of transmitting only the lower sideband, with suppressed, reduced or full carrier, respectively. A3E or A3EG -Ordinary amplitude modulation used for low frequency and medium frequency AM broadcasting J3E - SSB speech communication, used on HF bands by marine, aeronautical and amateur users R3E - SSB with reduced carrier (AME) speech communication, primarily used on HF bands by the military (a.k.a. compatible sideband) H3E - AM, single sideband, full carrier But yes, even narrow FM would be too wide at 10-15kHz. § 95.973 CBRS authorized bandwidth. Each CBRS transmitter type must be designed such that the occupied bandwidth does not exceed the authorized bandwidth for the emission type under test. (a) AM. The authorized bandwidth for emission type A3E is 8 kHz. (b) SSB. The authorized bandwidth for emission types J3E, R3E, and H3E is 4 kHz. "Enter the UHF version of CB which allows for FM modulation." That could be interesting, but would be even more line-of-sight than CB is.