eSSB - Extended Single Sideband

eSSB - Extended Single Sideband Audio
eSSB History


What Is eSSB?

eSSB Links
eSSB History

Old History

While the term “eSSB” is a relatively new term used to describe the extended nature of higher fidelity single sideband (coined January of 2003 by NU9N), the experimentation with high fidelity single sideband is not so new. Amateur radio operators have been experimenting with good single sideband audio, in one way or another, ever since single sideband was developed.

However, fairly recent changes in technology, with the introduction of “Digital Signal Processing” (DSP) and better I.F. filter schemes, have made high-fidelity SSB much more widely available. Therefore, it is the last few generations of amateur radio technology and the operators who have taken advantage of it, that will be covered here regarding eSSB history.

Recent History and the First Phase (1990~1999)

In the early 1990's, a group of amateur radio operators, who were tired of the poor audio quality (generally associated with single sideband), decided to improve the intelligibility and quality of SSB to a more natural sounding mode and paying particular attention to very low distortion of the audio envelope produced.

During this early period, W2ONV and WA2JVM were modifying D-104’s and microphone wind socks, trying to achieve a "Broadcast Quality" sound, using the SSB mode. A friend of WA2JVM (now W2JVM), Michael EA3OT, was also pursuing a better sound.

EA3OT called a friend of his, G0BBD, Eddy Beneau. It was Eddy, a retired A & R (artists & repertoire) man for RCA records, now retired in London, who told EA3OT about his use of a car 8-band audio equalizer that he was using on his 950SD, to improve his sound. Eddy told Michael to find an EQ from a stereo system, car audio, or whatever, and hook it up to the transceiver's microphone input. Michael remembered that his son, at the time, was forming a kids rock band, so he borrowed a Roland Boss Graphic EQ, resulting in the infancy of high quality SSB.

No one at first could obtain the sound of G0BBD because he was using a Kenwood TS-950SD, giving him a natural 0 to 3500 Hz audio range. Immediately, the SSB audio research group, that were all using the Yaesu FT-1000 (100 to 2800 Hz), were exchanging their rigs for the wider audio produced by the Kenwood products.

Harold, reporting to a now forming audio group on 20 meters, told about EA3OT startling to explore a better sounding SSB and the equipment that he was using. Immediately the world of audio processors, "Black Boxes" from the recording/music industry, was opened to the world of amateur radio and was achieving some very interesting and good sounding audio results. SSB audio would never be the same!

The initial group, operating in the 20 meter band on a frequency of 14.205 MHz., consisting of W2ONV as the moderator, G0BBD, EA3OT, W2JVM, KC4PE, and K2GX met daily, discussing new equipment, new applications, and now the use of professional microphones. They employed the use of external audio equalizers to shape the audio characteristics of their transmitters. More importantly, they were all using the new Kenwood TS-950SDX (with DSP built-in) which by default provided a transmitted audio bandwidth of about 3.8kHz. With a little EQing of the external audio feed, 4kHz to 4.5kHz of audio could be easily accomplished.

It should be noted that the single most driving force behind the initial SSB audio experimentation was Bill Salerno, W2ONV. He was often referred to as "The Godfather of SSB Audio", and for good reason. Bill's relentless enthusiasm for good audio, combined with his diplomatic and infectious way of speaking about audio, made for an irresistible combination for those listening. Bill was the most elegant and charismatic advocate for SSB audio experimentation and everyone knew it! He had a style about him, that made everyone who listened to him, want to be a part of this exciting mode of operating. May he rest in peace.

It should also be noted that Bill Winkis, KC4PE, also had a major influence on driving the SSB audio experimentation to the next level, by way of his background and business in home theater installations and in his interesting way of providing information to his colleagues and newcomers. KC4PE was also the first to provide a website dedicated to SSB audio processing. It was the only source available at the time for implementing external audio processing for amateur radio ssb.

Word spread rapidly! Commercial short wave SSB broadcasters were contacting the group seeking information and equipment choices in order to improve their commercial broadcast sound. Stations in Australia bought and ordered just about everything the SSB audio groups were using, to try and improve their broadcasts.

To facilitate and better document what results were being achieved, these operators started using a more complex audio chain, including the use of mixers and Mini-Disc recording equipment in order to record and playback each other with some reasonable, but not perfect results.

By 1995, the group of SSB audio enthusiasts had grown to about a dozen operators and moved operations to 14.188 MHz due to some DX conflicts on 14.205 MHz. The Kenwood TS-950SDX and Kenwood TS-870S had become the preferred transceivers for SSB audio experimentation because of their wider bandwidth capabilities. They were perfect for experimentation.

In 1996, the SSB audio group moved again to 14.177 MHz and then shortly thereafter to 14.178 MHz.

By 1998, some of the notable operators pushing the quality envelope were VE6CQ, WA6OT, KA0KA, W9NHQ, W6WM, and KK7TV. There were others of course, but these operators were making the most impact with their contributions.

By the late 1990's, SSB audio experimentation started gaining an even wider audience and became the default subject on 14.178, the home base of these experiments. On any given morning, there would be at least 50 or more stations participating, using ICOM's, Yaesu's, Ten-Tec's and anything else that showed any promise to support the new sound of quality SSB audio via external audio processing.

The Second Phase (2000~2001)

In March, 2000, NU9N, John, arrived on the scene with a modified Kenwood TS-940S and an interest in what was happening on 14.178. It wasn't long before he acquired a new Kenwood TS-950SDX and jumped in head first into the audio game. John realized fairly quickly, that the conventional mini-disc recordings that were being played back on the air, with no EQ compensation for transmitter response, were somewhat flawed and was in desperate need of reform.

Taking advantage of his computer sound card, he developed a near perfect procedure for accurate re-transmission of recorded on-air recordings using a software program called "Cool-Edit". The new computer recording scheme used was 16 bit, 44,100 sampling rate using the “Windows PCM Wave” format (CD quality). With the use of FFT filtering for flattening of the re-transmitted playback audio, combined with the flat receiver capabilities of the Kenwood TS-950SDX, the resulting playback quality was now good enough for stations to accurately hear themselves played-back.

Because of the inherent RFI and hum problems associated with combining external audio processing equipment, stereo equipment, and computers in an RF environment, NU9N developed a website of his own. The goal was to help ease the difficulties in setting up a high quality station for newcomers with these problems, offering even more information and providing a good source of educational and “How To” audio information on the web. The first mention of "Extended Single Sideband" (eSSB) was posted and defined on his web site in January of 2003.

By this time, those who were using the Kenwood TS-950SDX with external audio processing (equalization and compression), were easily accomplishing 4.5 ~ 5 kHz of audio frequency response. The interest in SSB audio experimentation flourished and started enjoying an unprecedented gain in popularity. Even though there was some initial resistance to the new sounds of high quality SSB audio, the experimentation continued. The race for better SSB audio became almost a competition for who could engineer the best audio from their station.

The Third Phase (2002)

In 2002, almost simultaneously, two operators, W5GI and W3HD independently stumbled on the older Kenwood TS-850 and Kenwood DSP-100 combination, discovering that this rig would easily allow a 6 kHz transmit band pass by way of DSP-100 rear-panel dip switch combinations. A new benchmark of high-fidelity SSB audio was discovered!

It wasn't long after this that a few brilliant operators (W9AC and W5JAY) figured out how to feed line-level audio directly to the DSP-100 as well as modifying the Kenwood 850 receiver for a flat 6 kHz receive band pass, making this transceiver the ultimate in SSB fidelity. Nothing had ever come close to what could be accomplished with this particular combination and would set a new standard of SSB fidelity for the next several years!

When the modifications had been perfected, several operators jumped on the Kenwood TS-850/DSP-100 bandwagon and began enjoying this new level of fidelity. The key participants were W3HD, W9AC, W5JAY, VE6CQ, NU9N, KA0KA, K2WS, and W3OZ.

Because of the inherent fidelity that the 850/DSP-100 combination provided, new skills in wider bandwidth processing had to be developed. Despite popular opinion, processing for wider bandwidths is no easier than for narrow bandwidths because balancing a wider range of frequencies adds more challenges and possibilities on how someone listening narrow will perceive this extended audio. For this reason, some important processing decisions had to be made by the eSSB operator as to who their target audience would be. Those listening narrow could never appreciate the full scope of the 6k transmitters. Conversely, if the 6k operators chose to EQ for the narrower listening audience, then the audio was compromised with those capable of listening in 6k. This was a problem and important bandwidth and EQing decisions had to be made to either accommodate narrow listeners or wide listeners, but not both at the same time without a severe compromise! As a result, this was the cause of some of the early conflicts in audio processing philosophy.

The Resistance Phase (2003~2007)

On the 20 meter band (primarily on 14.178 MHz), where most of the eSSB experimentation was being initially conducted, there were a few narrow-minded operators who believed that the extended bandwidth occupied by the higher quality audio was unnecessary—even wrong, and started an anti-eSSB campaign to make the new mode illegal.

During April and May of 2003, a few petitions were filed with the FCC by these disgruntled operators in an attempt to ban such experimentation. The attempts failed. The FCC made the decision in all cases, that the fundamental philosophy of amateur radio was not being violated and continue to this day to support such experimentation and operation. (See the FCC decision here...)

In May of 2005, the ARRL filed its own petition. Their petition was another attempt to regulate amateur radio bandwidth by limiting SSB occupied RF bandwidth to no more than 3kHz and AM RF bandwidth to 6kHz. The FCC rejected this proposal also.

In November of 2005, the ARRL tried it again, and it failed again.

In November of 2007, the ARRL managed to slip in some interesting new language in IARU Region 2 mandates. Even though the ARRL did not get their way with the FCC, they are still attempting to push their agenda forward through the IARU Region 2 back door so to speak. They will ague, I'm sure, at some point in the future, that the policies set forth in the IARU Region 2, should be adopted into FCC Part 97 law regarding U.S. operating regulations.

The Splinter Phase (2003)

Whenever and wherever there are pressures against a group of individuals who share a common cause, conflicts will arise within the group that causes divisions. The law of "Divide and Conquer" is in play here.

When the pressures against the eSSB establishment started to arise, and the petitions against certain individuals and activities in the eSSB camp were filed, accusations and conflicts started to arise within the eSSB community itself. What was at one time a strong allegiance of eSSB operators, diminished by friction into several splinter groups. The splinter eSSB groups still shared that same overall philosophy, but differed in its application and scope.

As a result, the 20 meter group on 14.178 MHz exploded in several directions and the main group of eSSB operators (about 50 in number) splintered to different portions of 20 meters, 15 meters, 40 meters, 80 meters, and 160 meters.

Several smaller eSSB groups formed, and are still forming. Even though there is no one large group of eSSB operators anywhere, the smaller groups have been increasing exponentially. One notable eSSB'er is Art Bell, W6OBB, who actively promoted eSSB on a few occasions during his evening nation-wide AM radio broadcast "Coast To Coast" program.

It should be noted that when the SSB audio experimentation splintered into several smaller groups, the term "eSSB" was somewhat redefined by those using the narrower bandwidth of less than 3kHz which was not in keeping with the original passion or experimentation. They were often referring to eSSB as being "Enhanced SSB" or even "Expanded SSB", neither of which were characteristic of the "Extended" nature of the original experimentation. While "Enhanced SSB" certainly sounds better than standard SSB, the term eSSB was never intended to mean anything other than high-fidelity SSB that was extended in bandwidth and audio (beyond 3k) to achieve the desired quality that ONLY a wider bandwidth can accomplish. Some may think that this is just a matter of semantics, but it is much more... "Extended SSB" is certainly an "enhanced" form of SSB, but "Enhanced SSB" is not necessarily "Extended SSB" beyond 3kHz, and so therein distinguishes the major difference.

Overall, the number of operators interested in Extended SSB is at an all time high. Virtually everywhere you listen, you will hear improved SSB audio, as opposed to just 10 years ago. eSSB has become an acceptable alternative for most reasonable operators and is accepted even by those who do not participate in the experimentation. Of course there will always be some resistance to anything relatively new, but this is just human nature and will always be with us in any activity. Splintered or not, eSSB is here to stay!

The "Voodoo" Phase (2005~Present)

The term "Voodoo Audio" was first used in 2000 by KK7TV (Randy) whenever he was referring to audio techniques that were derived from non-scientific and uneducated ways of processing audio. The term "Voodoo Audio" was an inside joke for several years referring to neophyte operators that didn't understand or follow accepted processing techniques.

WZ5Q (Mike) and NU9N (John) were having a light debate one evening regarding low-frequency harmonic processing (i.e. Behringer EX3200, BBE Sonic Maximizer, Aphex Aural Exciter, etc..), tube equipment vs. solid state, and analog vs. digitally based equipment, to achieve richer low-frequency harmonics. WZ5Q was making an argument in favor of these methods, proclaiming that the sonic characteristics would be beneficial and noticeable. NU9N was making the argument that all of these things would not produce any real benefits or noticeable differences on the air, referring to them as "Voodoo".

They both got a good laugh out of the discussion and remain friends to this day. But WZ5Q started referring to his station as being "Voodoo" speaking tongue in cheek, and the term has caught on as the trademark for the low frequency harmonic advocates.

Another huge contribution that was presented by Mike, WZ5Q in the mid 2000's, was his modifications to the Kenwood TS-950SDX after he discovered how to unlock wider bandwidth capabilities of the 950SDX via a previously hidden secret menu. Mike took the time to refine the 950SDX by improving just about every audio circuit in the 950SDX. He spared no expense at making the newly modified Kenwood TS-950SDX the finest eSSB rig available anywhere on the planet! In fact, it could be argued that the WZ5Q "Voodoo" modified Kenwood TS-950SDX is still the ultimate eSSB standard in audio quality. For a number of years, Mike modified these 950's for a very discriminating niche group of eSSB enthusiasts who demanded the very best in audio fidelity. If you ever run across anyone using one of these "Voodoo" modified Kenwood TS-950SDX rigs, you will know it because they sound like nothing else available on the market!!!

"Voodoo Audio" does seem to have some merit and may not really be Voodoo after all. It is well known and documented, by true hi-fi audiophiles, that tube and analog technology has some favorable sonic advantages over solid state and digital devices, where soothing even-harmonic resonance is involved. Those involved in the "Voodoo" movement also experiment with rolling their own Op Amp's, using vintage tubes, and performing other sonic modifications such as hi-fi input/output mods, power supply mods that deliver a purer, more consistent voltage to the circuits and so on.

"Voodoo audio" is alive and well and can be found at the"Voodoo Labs" website:

The Latest Phase (2007~Present)

With newer generations of amateur radio equipment being developed (Flex, Anan, etc..), eSSB is possible with most of these newer generation transceivers. Amateur radio manufacturers have built-in accommodations for those interested in higher quality SSB and eSSB audio.

Digital Signal Processing (DSP) has opened up a whole new frontier and possibilities for higher quality SSB audio than what was generally possible a few years ago. Software defined radios are the new kids on the block and have great potential for a wide arena of operating possibilities.

There have been some very exciting experimentation going on using the Flex SDR 5000 and SDR 6000 by Alan, K2WS, and Dave, W9AD and some others leading the way with the Anan 8000 rigs. These two individuals have contributed greatly to the on-air usage and experimentations of this new generation of software defined radio. In fact, there are many SDR operators out there continuing the audio experimentations.

It's becoming rare these days to find an operator that has NOT employed some sort of audio processing in their station. It's becoming more recognized that the improved fidelity of eSSB has signal-to-noise advantages over the old traditional forms of narrower SSB. And, with the decline of new amateur radio operators to populate the bands, the wider bandwidth necessary for high quality SSB is not as much of an issue as it was 10 or 20 years ago.

Where Is Everyone Now?

eSSB operators are alive and well and active on the amateur bands. There are several established eSSB groups and operators. The list below is not complete, but should cover most of the eSSB operations and experimentation.

20 Meters

80 Meters

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