[SCCC] AM to SSB transition

[Tree]

Great to hear about the history that predates when I got on the air.
Another contributor to the transition was the relatively inexpensive Swan
350 - which probably was introduced in 1964 or 1965.

Tree N6TR

On Mon, Dec 17, 2018 at 10:28 AM W6PH via SCCC <sccc at contesting.com> wrote:

> Wayne said it all.  I am 1955 vintage and this is exactly as I remember it.
> Collins was the forefront for SSB.  The Strategic Air Command needed
> reliable communication in the polar regions for control of its bombers.
> SSB solved the problems with AM distortion in the auroral regions.
>
> SSB was developed in the late 40's for use by hams.  There are many
> articles in QST showing how to mathematically eliminate the carrier and
> eliminate one sideband.  It was called the phasing method and several
> manufacturers came out with these transmitters.  Collins took a different
> approach and used a balanced modulator and mechanical filter to produce the
> single sideband suppressed carrier signal.  It was produced on a single
> frequency and a heterodyne scheme was used to vary the frequency.  Using
> the heterodyne principle led to the transceiver which used the same VFO to
> vary both the transmit and receive frequency.  The KWM-1 was the first
> widely available transceiver and could be used either as a home station or
> a mobile station.
> Heath Company and EF Johnson came out with what they called sideband
> adapters which were made to convert a normal AM-CW transmitter to SSB using
> the phasing method.  I converted my DX-100 for implementation of the SB-10
> but never bought the SB-10.  Instead the SB-400 came out and was a better
> choice to get on SSB.  The Heathkit SB series was the poor man's Collins
> S-Line clone.
> There was also a short period of interest in double sideband suppressed
> carrier or DSB.  Instead of producing the signal at a low level and
> amplifying, it was produced using balanced modulator techniques in the
> final tubes.  The control grids of the final tubes were directly driven and
> the output was operated push-pull.  The screen grids were driven with an
> audio signal in a push=pull arrangement.  However, the interest was very
> limited as it was one sideband too many!
> Due to the availability of SSB gear at reasonable prices and the
> advantages of SSB, it became very popular very quickly.  Wayne is
> absolutely correct in his time lines.
>
> 73, Kurt W6PH
> In a message dated 12/16/2018 7:59:05 PM Pacific Standard Time,
> sccc at contesting.com writes:
>
> Dennis, I'd really like to see some discussion of the AM-to-SSB transition
> here on the SCCC list.  It would be fun to read what others remember from
> those days.  Here are some of my recollections.
> As a young ham in the 1950s I operated several contests on AM before SSB
> became the mainstream voice mode on the HF bands.  The high point for me
> was 1959 Phone Sweepstakes.  I finished second in the L.A. section, running
> a Heathkit DX-100 transmitter and Hallicrafters SX-101 receiver to a
> 2-element cubical quad for 10 and 15 meters (up 25 feet at the center--not
> very high even by 1959 standards).  The guy who beat me (W6LNW) was #2
> nationally and he had much bigger antennas than I did.  Size mattered, as
> it still does.
> QST published a list of the equipment used by all of the section leaders
> in those days.  In 1959 almost all of the winners were running AM
> transmitters like Viking Valiants, DX-100s or the earlier Viking I and
> Viking II rigs.  I don't think there was much SSB activity in Phone
> Sweepstakes until a few years later.  I went off to college and didn't
> operate SS for several years after 1959.
> By 1965, however, everything had changed.  Almost all of the section
> leaders were running SSB rigs and operating the contest mainly on SSB.  At
> the same time, overall voice activity dramatically increased.  In 1959
> Sweepstakes, CW logs outnumbered phone logs by a 3:1 ratio.  By 1965, the
> ratio of CW logs to phone logs was only 5:4.  There were more phone logs
> than CW logs in SS for the first time in 1970, according to the tallies of
> Ellen White, W1YYM (now W1YL), who wrote most of the SS articles for QST in
> that era.
> Clearly, the transition to SSB led to a major increase in overall voice
> activity in Sweepstakes.  However, it didn't lead to the kind of increase
> in overall scores that you might expect.  In 1959, the top phone scores
> were over 200K (on AM), not that much lower that the top phone scores now,
> 60 years later.  However, that's really comparing apples to oranges because
> there was a power multiplier then.  Also, the maximum operating period on
> each mode was longer than it is today.  And to be honest, I don't think
> anyone worried much about "rubber clocking" until the 1970s.  Most of us
> didn't operate anywhere near the maximum time allowed.
> I don't remember the best receivers of the 1950s being that bad.  They had
> good sensitivity and selectivity on the HF bands, even 10 meters.  What was
> different was the HETERODYNES on the bands.  With all those AM carriers,
> during SS the phone bands were a sea of squeals and whistles.  Receivers
> had notch filters, but you couldn't eliminate all of the squeals.  (Null
> one out and another one would pop up.)
> Voice operating didn't seem all that different back then--except for the
> awful QRM.
>  With my DX-100 (about 100 watts of high-level plate modulated AM), I
> could hold a frequency and run all day on 10 or 15.  S&P was a pain,
> though.  Without a transceive mode you had to zero-beat every station that
> you called.  I very much preferred running--and I hated it when 15 dropped
> out to the east.  I couldn't ever hold a frequency and run on 40 meters.
> W6LNW, the guy who beat me in '59 phone SS, could hold a frequency and run
> all night on 40.  I spent some envious times listening to him.  Size
> mattered.  Um, did I say that before?
> Just some random memories of phone contesting in 1959...
> 73, Wayne, N6NB (K6YNB back then)
>
>
>
> --------------------------------------------On Sun, 12/16/18, Dennis
> Younker NE6I <NE6I at cox.net> wrote:
> Subject: Re: [SCCC] Looking For Write Ups, Comments, Observations AM to
> SSBTo: sccc at contesting.comDate: Sunday, December 16, 2018, 4:02 PM
> Some really good stuff has beensent along to me for the upcoming
> article.Does anyone have any old photos of that timeperiod? Station photos
> from the1950s and60s would be a great add to the article! As well,
> yourcontestexperience during that time framewould be interesting. What was
> it like tooperate a contest where both AM and SSBco-existed on the bands?
> Receiverswere soless capable back then that I can only imagine
> howchallenging itwas for a few years there.
> As before, please reply onlyto me so that I can capture your comments
> andphotos for the article. Thanks!
> --Dennis NE6I
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