Asymmetrical
'D' shaped Constellation
I am an enthusiat & collector, and not a trained horologist,
this service has come out of my hobby of collecting watches with the ESA tuning
fork movement. Having become frustrated by the lack of repairers prepared or
able to fix and service my collection, I decided to have a go myself.
This has been at times a very stressful and expensive learning curve.
Having successfully serviced and repaired my own watches and well as ones for
other owners over the years, I feel the time has now come to be able to offer
the benefit of my experience to a wider audience.
There are so many styles and models to chose from, and with
their characteristic hum and perfectly sweeping second hand these watches make
an interesting & accurate alternative to other vintage timepieces.
As an important part of 70’s Horological history, it is my opinion these
tuning fork watches are sure to increase in value in the future.
GP Eterna Sonic
Developed jointly by Omega and ESA under license from Bulova,
these tuning fork movements, designed by Max Hetzel were used by many of the
Swiss makers in the early to late 1970’s.
This was a Chronometer grade movement, with a -/+ of 2secs per day, although
it appears that only Omega's f300 and certain Certina Certronic models that were marketed as such. They are prone to some drift
caused by temperature change, but can be adjusted to compensate depending on
the local climate.
Relatively expensive to produce it was eventually killed off
by the influx of Quartz movements of the day, which were generally cheaper to manufactuer and considered more reliable.
Briefly resurrected by Technos in the early 90’s who produce a limited
run of 10,000 pieces with old stock and parts purchased from ESA. Probably the
reason why parts are so scarce today!
Perhaps the most commonly known watch to feature these movements
is the Omega f300, which was available in a vast array of styles and models,
featuring both Date only (cal 1250) and Day/date (cal 1260). A Chronograph version
was also produced, more on that later.
Some models are quite common and at current values are reasonably cheap to acquire,
there are some rarer variants, most notably the diver versions, Asymmetrical
‘D’ shaped Constellation and several models produced in both solid
9kt and 18kt gold.
To my current knowledge the following makers all produced models featuring the ESA tuning fork movement.
· Baume & Mercier – Tronosonic
(cal 19162, cal 19164)
· Bucherer Electronic ( unkown)
· Certina - Certronic/c-tronic (cal 29-151, cal 29-152)
· Derby - Derbysonic (Longines movements)
· Eterna - Eterna Sonic (cal 1550, Cal 1551)
· Imado - Tuning fork ( non branded)
· IWC - Electronic, sometimes known as Edison electronic
( cal .150, cal .160)
· Longines – Ultronic (cal 6312, cal 6332 )
· Rado - electrosonic I think (possibly in conjunction
with Certina)
· Technos – Tuning fork Mosaba. Limited run in
the early 90’s some 10 yrs after production of these movements had stopped.
· Tissot - Tissonic (cal 2010, cal 2020)
· Titus – Tuning fork (not branded)
· Zenith – Xltronic, also marketed as Allegro
and Movado (cal 50.0 and cal 50.5)
Most of these makers produced both Date only and Day/date versions.
All would make an interesting, reliable, and accurate alternative
to today’s offerings.
I am sure there are probably others and I will update the information if I learn
more.
Any help or info regarding any other manufactures or cal No’s etc would
be gratefully received.
Certina
C-tronic Chronolympic
There was also a Chronograph version produced, the ESA 9210.
This is essentially a 9162/4 movement with a Chronograph module made by Dubois
Depraz SA added. Only around 21,000 units of this movement were produced.
It is widely thought that Omega had around 11,900 for their Speedsonic range
of watches (cal 1255), which was the first electronic Chronograph Chronometer,
and also the first Omega Chronograph from the Speedmaster family with a Day/Date
feature.
Omega marketed at least 5 variants of this model, and with such a low production
run, makes them much rarer than some of the so-called limited editions Omega
have produced.
Other makers also produced Chronographs with this movement, certainly Longines,
Certina, Derby, and Baume & Mercier
These models are also very rare and as such highly sort after.
Longines Ultronic Chronograph Cal L749.2
Please e-mail your requirements to
KeithTilley@Omega-f300hz.co.uk
