Well from my internet surfing I've managed to dig out the following information on the history of the Omega Seamaster f300 Hz. The f300 Hz movements were developed jointly by Omega and ESA under license from Bulova. They were used by a number of manufacturers in the 1970's. Omega suggested service intervals of 5-6 years, which shows these are a hardy movement that can still be found running strongly in many watches.
Tuning fork movements, although more accurate than mechanical movements, were quickly replaced by quartz movements that were cheaper to produce and seen as more accurate. The era of the tuning fork movement was therefore short lived and many will miss out on owning one of these outstanding timepieces.
A small battery powers the f300 Hz tuning fork movement in the Omega. A miniature transductor sets a resonator vibrating at 300 oscillations per second (300 Hz). These oscillations are maintained by an electronic circuit and divided into units of time.
As the wrist is turned the resonator is subject to differing strengths of gravitational pull. To cope with this Omega counter balance the resonator to nullify these effects. This and the use of electrical circuits ensure consistent time keeping and Omega claimed accuracy within 2 seconds per day, i.e. accuracy of 99.9977%. Pretty damn accurate in my opinion!
My watch dates from 1973, so is 35 years old. Over the last week it has gained around 14 seconds, i.e. 2 seconds per day. Exactly as specified by Omega and probably my most accurate piece at the moment.
The vibrating resonator causes the movement to gently hum, which has resulted in watches with these movements often being called hummers. The movement also provides for a sweep second hand rather than the ticking hand seen on quartz watches, and was one of the main attractions for me.
SCORE : 9/10
There were two types of case for the Seamaster f300 Hz; one for use with an integrated Omega bracelet, the other with hidden lugs that came on a strap. Both cases are made of stainless steel with a screw in back to give the watch its 120m water resistance rating.
Although, relatively old the case is of a good size, approximately 40mm excluding crown and around 45mm lug tip to lug tip. This makes it easily wearable in the current environment of large watches, without it being ridiculously oversized.
My watch has the integrated Omega bracelet and is reasonable condition for its age. It has a small ding by the crown and general scuffmarks that could easily be tidied up. Overall it sits comfortably on my wrist and I like the simple shape. I would prefer to have the option of other straps but the bracelet is good enough that this isn’t a big issue.
SCORE : 7/10 (reflecting the integrated bracelet and condition of mine)
The bracelet is fairly unusual starting at a wide 26mm to match the shape of the case and rapidly tapering down to a narrow 15mm. The measurements sound unusual and I am not usually a fan of tapering straps, but it seems to work well in this case and does not look out of place. In fact the taper on the bracelet is designed to follow the taper of the case from crown to lugs.
The bracelet clasp is a straightforward clip, with an omega logo on it. It clips in tightly and does not feel as if it would come loose easily, although I would prefer a push button clasp as I always feel they are more secure. Small adjustments can be made to the bracelet by varying the position of the bracelet end within the clasp. I have not yet looked into how you can remove or increase the links in the bracelet.
SCORE : 7/10 (integrated and no divers extension)
The Seamaster f300 Hz was produced with a number of different dials. There are at least 4 variations as noted in the DeskDivers article; two-tone silver, black, brushed silver and silver with a silver logo. I have the matte black dial, which has minute indices with bolder indices every 5 minutes and bold, long indices every 15 minutes except at 3 o’clock where the date window is.
The date window as stated is at 3 o’clock and is metal edged. The dial has a red backed Omega logo applied at 12 o’clock, which leaves plenty of room for the minimal writing that appears on the dial. The writing that does appear on the dial “Omega Electronic f300 Hz”, “Seamaster Chronometer” and “Swiss Made” is well proportioned and uses a nice sharp font.
I am not sure whether the original luminescence on the dial was from tritium or something else (tritium I believe). Whatever it was the luminescent power is well and truly exhausted on my watch and is one of the only things I would be tempted to change, although I knew the lume would be non-existent before I bought.
All in all a nice simple dial with a few touches to add a bit of class.
SCORE : 8/10
The hands are stick hands, similar in appearance to those on a GSAR, but without the thickness caused by the tritium tubes. The hands are simple and the tails are short. The second’s hand is a lovely red colour to match the applied Omega logo.
Some people may find the hands too narrow for the watch, given the current fashion of large, broad hands. I, however, think they match the dial and elegance of the watch well.
As with the dial I believe the hands original had tritium luminescence, and again this has well and truly worn off leaving no lume at all. The sight of the red seconds hand sweeping round the dial as the movement hums away more than makes up for this J
SCORE : 8/10
The bezel on these watches is rather unique, which leads to some interesting pros and cons. It is a 60 click bi-directional bezel that requires a firm pressure to turn. There is no play at all on the bezel on my watch; once it is turned and clicks it is solidly in place until turned further. The bezel itself is made of Bakelite poured into the stainless steel bezel shell, thus necessitating a completely new bezel if any damage occurs.
Bakelite was the worlds first synthetic plastic and is electrically nonconductive and has good heat-resistance. This makes for a fairly hardy bezel, although they are prone to scratching. Small scratches can be polished out with polywatch or similar, but more serious damage can allow water to penetrate.
As with the dial and hands I believe tritium was used to provide luminescence and again this is now worn out. The bezel on my watch is in pretty good condition, although it does have some discolouration around the 6 o’clock area. Given the age of the watch though, and the fact that the bezel is probably original as very few have been changed, it is very impressive.
SCORE : 8/10
I am very impressed with this watch. It provides the pick-up and go, as well as the accuracy, of quartz combined with the sweeping seconds of a mechanical. Add to this its own unique hum and the movement ticks a lot of boxes for me. The design of the case, dial, hands and bracelet are simple, elegant and timeless. This is a watch I would be happy to wear for many years.
*This review was originally written by mattgj01 on tz-uk. All credits go to him.