CALIBER/browser
CORPUS EXPORT · 12269 calibers · 59387 family views · round round/2026-09-08Compiled from app/public/data/ · corpus 70c0140eba.
Family treeBulova 10BT (AS 1200) — Heritage family: 9 calibers, 8 sourced lineage links.Drag to explore.
100%drag to pan · hover a caliber to isolate its line · scroll the page normallyopen the full family view →
ébauche ofébauche ofébauche ofébauche ofébauche ofébauche ofébauche ofébauche ofAS 1200 — open caliber pageAS 1200—maker not sourc…1 exec · grade ?Bulova 10BC (AS 1200) — open caliber pageBulova 10BC (AS 120…1944maker not sourced1 exec · grade ?Bulova 10BCC (AS 1200) — open caliber pageBulova 10BCC (AS 120…1946maker not sourced1 exec · grade ?Bulova 10BS (AS 1200) — open caliber pageBulova 10BS (AS 120…1943maker not sourced1 exec · grade ?Bulova 10BT (AS 1200) — the caliber this page is aboutBulova 10BT (AS 120…1950maker not sourced1 exec · grade ?Bulova 10BTC (AS 1200) — open caliber pageBulova 10BTC (AS 120…1951maker not sourced1 exec · grade ?Bulova 10BU (AS 1200) — open caliber pageBulova 10BU (AS 120…1951maker not sourced1 exec · grade ?Bulova 10BUC (AS 1200) — open caliber pageBulova 10BUC (AS 120…1951maker not sourced1 exec · grade ?Bulova 10ZCC (AS 1200) — open caliber pageBulova 10ZCC (AS 1200)—maker not sourc…1 exec · grade ?
accepteddisputed
Sense of “family”Heritage · 9Everything (debug) · 9Parts cluster (Jules Borel sense) · 1Manufacturer-internal (Ranfft sense) · 1Based-on star (WatchBase sense) · 9Open the full family view →

movement

Bulova 10BT (AS 1200)

maker not sourcedintroduced 1950design:bulova-10btcompare specs · 2
bounding evidence — no range is drawn on the era axis
not after 1952
a dated example movement, 1952“1952: L2, BXW, Bulova Watch Co, Swiss, 15 Jewels”
not after 1952
a dated example movement, 1952“1952: L2, BXW, Bulova Watch Co, Swiss, 15 Jewels”

Identity

A caliber is three separate things and this reference keeps them apart: the construction, the names it is sold under, and the article a brand actually bought. A watch model points at an execution — never at a bare construction — which is why “same caliber” is almost never a complete answer.

IDesign — the construction
Bulova 10BT (AS 1200)
movement
IIDesignations — 0 names

No designation is recorded for this design yet.

IIIExecutions — 1 article

No source in this corpus states which grade any Bulova 10BT (AS 1200) was bought at. That unknown is stored as a real row rather than left blank, so it can be counted, filtered and excluded from any comparison that would otherwise assume parity.

unknownsynthetic
evidence: unknown

no source states which grade this article was bought at — this row exists so 'unknown' stays countable instead of becoming an assumption

exec:bulova-10bt/unknown

Specifications

PropertyValueScopeStatusSources
Jewels
build.jewel_count
7Ranfft data sheet, the 7-jewel member of its 7/15/17 rangestaged
Jewels
build.jewel_count
15Ranfft data sheet, the 15-jewel member of its 7/15/17 rangestaged
Jewels
build.jewel_count
17Ranfft data sheet, the 17-jewel member of its 7/15/17 rangestaged
Seconds display
disp.seconds_display
small—staged
Casing diameter
geom.casing_diameter_mm
23.7 mm—staged
Movement diameter
geom.diameter_mm
23.3 mm—staged
Movement height
geom.height_mm
3.5 mm—staged
Frequency
osc.frequency_vph
18000 vph—staged
Power reserve (typical)
power.reserve_typical_h
45 h—staged
Discontinued
prod.discontinued_year
1954—staged
Introduced
prod.intro_year
1950—staged
Winding mode
wind.mode
manual—staged

Where a property carries more than one value, the values have different scopes — an official spec sheet and observed hardware, say. Different scopes are not a disagreement, so both are accepted and both are shown with the scope they apply to.

Lineage

The same relationships as the tree at the top of this page, with their sources. An absence in a column means no source stated one.

Ancestors · 1

Where this construction came from. Read up the arrows.

Descendants · 0

What came from it — revisions, variants, clones, licensed copies.

None recorded. An absence here means no source stated one, not that none exists.

Related · 0

Stored in a different table from descent. A successor is not a child.

None recorded. An absence here means no source stated one, not that none exists.

Sources

  1. 1
    Internet Archive
    https://web.archive.org/web/20181106113753/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&Bulova_10BT
    archivetier 2retrieved 2018-11-0614 facts on this page
  2. 2
    Internet Archive
    https://web.archive.org/web/20181106113747/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&Bulova_10BS
    archivetier 2retrieved 2018-11-062 facts on this page
  3. 3
    Internet Archive
    https://web.archive.org/web/20230905233650/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bulova_10BC&
    archivetier 2retrieved 2023-09-051 fact on this page
  4. 4
    Internet Archive
    https://web.archive.org/web/20230905233806/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bulova_10BCC&
    archivetier 2retrieved 2023-09-051 fact on this page
  5. 5
    Internet Archive
    https://web.archive.org/web/20191021223310/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&Bulova_10BTC
    archivetier 2retrieved 2019-10-211 fact on this page
  6. 6
    Internet Archive
    https://web.archive.org/web/20191215182538/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bulova_10BU
    archivetier 2retrieved 2019-12-151 fact on this page
  7. 7
    Internet Archive
    https://web.archive.org/web/20230905235932/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bulova_10BUC&
    archivetier 2retrieved 2023-09-051 fact on this page
  8. 8
    Internet Archive
    https://web.archive.org/web/20191021022351/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&Bulova_10ZCC
    archivetier 2retrieved 2019-10-211 fact on this page