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SSB Broadcast
- Thread starter K6JHU
- Start date
Plenty of shortwave receivers of all generations have SSB capability, often via a Beat Frequency Oscillator (BFO) in vintage units, originally used for CW Morse Code. Pretty much necessary for listening on the ham bands.
The station you heard is WJHR in Milton, Florida, near Pensacola.
Back in the 1980s there was a lot of chatter about shortwave broadcasters adopting SSB to replace AM modulation. Never happened; a major issue is having to be precisely tuned for the audio to reproduce correctly. If slightly mistuned, spoken word is still intelligible, but music quickly falls apart.
The station you heard is WJHR in Milton, Florida, near Pensacola.
Back in the 1980s there was a lot of chatter about shortwave broadcasters adopting SSB to replace AM modulation. Never happened; a major issue is having to be precisely tuned for the audio to reproduce correctly. If slightly mistuned, spoken word is still intelligible, but music quickly falls apart.
You think music sounds bad in AM, try listening to it in single sideband, even precisely tuned!Plenty of shortwave receivers of all generations have SSB capability, often via a Beat Frequency Oscillator (BFO) in vintage units, originally used for CW Morse Code. Pretty much necessary for listening on the ham bands.
The station you heard is WJHR in Milton, Florida, near Pensacola.
Back in the 1980s there was a lot of chatter about shortwave broadcasters adopting SSB to replace AM modulation. Never happened; a major issue is having to be precisely tuned for the audio to reproduce correctly. If slightly mistuned, spoken word is still intelligible, but music quickly falls apart.
For good reason. There's nothing preventing hams from initiating contacts (or nets) 3 kHz up or down from one already taking place. A wider bandwidth would be useless under those circumstances.There's also the issue of received bandwidth of modern ham/shortwave equipment. While AM filters can be as wide as 6 kHz, with narrower bandwidths included in some cases, SSB is usually restricted to 2.7 kHz at best.
Power levels for SSB are expressed differently than AM since there is no carrier, as the power output greatly varies with the audio waveform. Usually there are references to ”average power” and “peak envelope power (PEP) which is the power level on audio peaks.At best WJHR is running 10 kw.. probably far less.
My Dad was a ham operator, and used SSB on the 6 meter band (50-54 MHz). His transmitter (a Heathkit SB-110A) had 100 watts average power output with 180 watts PEP.
The 2025 World Radio TV Handbook lists WJHR with 250 watts and 1kw PEP.
Presumably that would've been SSB with carrier, like Kahn Power-Side, to maintain compatibility with conventional AM receivers and avoid the robotic sound that carrier-less SSB has unless the receiver is tuned in perfectly.Back in the 1980s there was a lot of chatter about shortwave broadcasters adopting SSB to replace AM modulation. Never happened; a major issue is having to be precisely tuned for the audio to reproduce correctly. If slightly mistuned, spoken word is still intelligible, but music quickly falls apart.
There used to be an ssb broadcast band right above the Amateur 15M band. So above 21.450 Mhz, if it still exists. I dunno.
The chatter in the 1980s was about pure SSB for broadcasting. But what you are thinking of is generally called “AM compatible single-sideband” or CSSB, which somewhat reduced the carrier and only used one sideband.Presumably that would've been SSB with carrier, like Kahn Power-Side, to maintain compatibility with conventional AM receivers and avoid the robotic sound that carrier-less SSB has unless the receiver is tuned in perfectly.
Radio Netherlands used CSSB on one of its frequencies beamed to North America from Bonaire in the 1990s. Spoken word audio sounded fine, but music could be a little rough at times. As you “tuned through” the signal it was not symmetrical as normal AM would be. A few other broadcasters tried CSSB as well. Canadian time signal station CHU is a current example.
The 13 meter international broadcast band (21450 to 21850 kHz) was never specifically a “SSB broadcast band”. A few broadcasters still use that range, but activity is way down from what it used to be.There used to be an ssb broadcast band right above the Amateur 15M band. So above 21.450 Mhz, if it still exists. I dunno.
There was (still is?) even an 11-meter band just below the CB range. Both it and 13 meters were used by broadcasters only during solar cycle peak years.The 13 meter international broadcast band (21450 to 21850 kHz) was never specifically a “SSB broadcast band”. A few broadcasters still use that range, but activity is way down from what it used to be.
The 11 meter international broadcast band still exists. Originally 25600 to 26100 kHz, the band was trimmed more recently to start at 25670.There was (still is?) even an 11-meter band just below the CB range. Both it and 13 meters were used by broadcasters only during solar cycle peak years.
There was never a lot of activity on 11 meters during shortwave’s heyday, though VOA, BBC, Radio Netherlands, Radio RSA (South Africa) and Radio Norway could be heard there, among a few other occasional users. Today it is rarely employed, though the BBC has used 25700 and 25900 for broadcasts to Africa in recent seasons.
13 meters was/is used throughout the solar cycle, though peak sunspot numbers increased the activity on the band. Usage way down these days with the demise in overall SW broadcasting.
Most of the users of the 11 meter broadcast band now are studio-transmitter links in the US. Sometimes they can be heard, when conditions are right.The 11 meter international broadcast band still exists. Originally 25600 to 26100 kHz, the band was trimmed more recently to start at 25670.
There was never a lot of activity on 11 meters during shortwave’s heyday, though VOA, BBC, Radio Netherlands, Radio RSA (South Africa) and Radio Norway could be heard there, among a few other occasional users. Today it is rarely employed, though the BBC has used 25700 and 25900 for broadcasts to Africa in recent seasons.
13 meters has a few years left of use. Once this solar cycle bottoms out, that'll likely be it for this band. By the time the next cycle peaks in the mid 2030s, there'll probably be half (at best) of the SW stations that exist today.13 meters was/is used throughout the solar cycle, though peak sunspot numbers increased the activity on the band. Usage way down these days with the demise in overall SW broadcasting.
Which has been "hardly ever" for much of this year. A never-ending series of coronal mass ejections has killed reception from 15 meters up for months now. Very disappointing for hams and SWLs who anticipate these sunspot peaks for years. This morning, even 20 and 40 were rubbish.Most of the users of the 11 meter broadcast band now are studio-transmitter links in the US. Sometimes they can be heard, when conditions are right.
There's also the issue of received bandwidth of modern ham/shortwave equipment. While AM filters can be as wide as 6 kHz, with narrower bandwidths included in some cases, SSB is usually restricted to 2.7 kHz at best.
When Voice of America was using the ISB feeder transmitters, the two sidebands had almost 6 Khz audio bandwidth each. We were running program audio on those ISB transmitters.
You think music sounds bad in AM, try listening to it in single sideband, even precisely tuned!
If the receiver is set up properly, the music will sound as good as regular AM.
When the Voice of America was using the RCA SSB R3 receivers, the normal set up was to use either one sideband or the other, if the received signal was AM. If the received signal was from one of the ISB transmitters, obviously, the proper sideband was used. Very little audio quality difference.
I remember those transmissions…weren’t they from the Greenville “C” site that was used solely for program routing and feeders, as opposed to the standard AM modulation at the “A” and “B” sites? Audio was quite good, though as they were ISB you had to have a receiver that could separately tune each sideband. Otherwise you’d hear a mix of two different programs!When Voice of America was using the ISB feeder transmitters, the two sidebands had almost 6 Khz audio bandwidth each. We were running program audio on those ISB transmitters.
True, but you need a receiver that is rock stable and precisely tunable. If the tuning is slightly off, the pitch of spoken word content will change while still being intelligible. However the harmonic relationships in music will be completely thrown off, resulting in a dissonant mess.If the receiver is set up properly, the music will sound as good as regular AM.
And this recent solar cycle being crappy compared to previous ones doesn't help it much. Declining eUV, less stations on the air, less hams using their spectrum unless it's FT8, combined with the CME's wiping out what's left, has made SWLing more of an adventure than a listening experience.Which has been "hardly ever" for much of this year. A never-ending series of coronal mass ejections has killed reception from 15 meters up for months now. Very disappointing for hams and SWLs who anticipate these sunspot peaks for years. This morning, even 20 and 40 were rubbish.
Tuning around short wave by the west Wales coast the other week, the strongest thing on the dial was the religious programming from WBCQ on 9330, which at the time was presumably beaming straight at us as it was S9+20 and in English.And this recent solar cycle being crappy compared to previous ones doesn't help it much. Declining eUV, less stations on the air, less hams using their spectrum unless it's FT8, combined with the CME's wiping out what's left, has made SWLing more of an adventure than a listening experience.
I've noticed the same thing as you on the ham bands - you tune around, e.g. 17m and think "there's nobody on, this band is closed" until you hit the FT8 frequency and hear the S9+ warbling. The band is wide open, there's just nobody on it apart from computers wailing at each other.