CALIBER/browser
CORPUS EXPORT · 12269 calibers · 59387 family views · round round/2026-09-08Compiled from app/public/data/ · corpus 70c0140eba.
Family treeBulova 8AD (ETA 1220) — Heritage family: 4 calibers, 3 sourced lineage links.Drag to explore.
100%overlaydrag to pan · hover a caliber to isolate its line · scroll the page normallyopen the full family view →
ébauche ofébauche ofébauche ofBulova 8AD (ETA 1220) — the caliber this page is aboutBulova 8AD (ETA 122…1948maker not sourced1 exec · grade ?Bulova 8BA (ETA 1220) — open caliber pageBulova 8BA (ETA 122…1947maker not sourced1 exec · grade ?ETA 1220 — open caliber pageETA 12201947ETA SA Manufacture Horlogère…1 exec · grade ?Wyler E1220 (ETA 1220) — open caliber pageWyler E1220 (ETA 1220)—maker not sourc…1 exec · grade ?
accepteddisputed
Sense of “family”Heritage · 4Everything (debug) · 4Parts cluster (Jules Borel sense) · 1Manufacturer-internal (Ranfft sense) · 1Based-on star (WatchBase sense) · 4Open the full family view →

movement

Bulova 8AD (ETA 1220)

maker not sourcedintroduced 1948design:bulova-8adcompare specs · 2
bounding evidence — no range is drawn on the era axis
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 Jewels”
not after 1948
a dated example movement, 1948“1948: 48, BXW, Bulova Watch Co, Swiss, 17 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 8AD (ETA 1220)
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 8AD (ETA 1220) 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-8ad/unknown

Specifications

PropertyValueScopeStatusSources
Jewels
build.jewel_count
17Ranfft data sheet, the 17-jewel member of its 17/21 rangestaged
Jewels
build.jewel_count
21Ranfft data sheet, the 21-jewel member of its 17/21 rangestaged
Movement shape
build.shape
rectangular—staged
Seconds display
disp.seconds_display
small—staged
Casing diameter
geom.casing_diameter_mm
22.2 mm—staged
Movement diameter
geom.diameter_mm
21.7 mm—staged
Movement height
geom.height_mm
3.25 mm—staged
Frequency
osc.frequency_vph
18000 vph—staged
Power reserve (typical)
power.reserve_typical_h
43 h—staged
Discontinued
prod.discontinued_year
1951—staged
Introduced
prod.intro_year
1948—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/20230906044753/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Bulova_8AD&
    archivetier 2retrieved 2023-09-0614 facts on this page
  2. 2
    Internet Archive
    https://web.archive.org/web/20181106155538/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1228
    archivetier 2retrieved 2018-11-061 fact on this page
  3. 3
    Internet Archive
    https://web.archive.org/web/20181106155551/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1230
    archivetier 2retrieved 2018-11-061 fact on this page
  4. 4
    Internet Archive
    https://web.archive.org/web/20181106155630/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1232
    archivetier 2retrieved 2018-11-061 fact on this page
  5. 5
    Internet Archive
    https://web.archive.org/web/20181106155636/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1233
    archivetier 2retrieved 2018-11-061 fact on this page
  6. 6
    Internet Archive
    https://web.archive.org/web/20181106155558/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1231
    archivetier 2retrieved 2018-11-061 fact on this page
  7. 7
    Internet Archive
    https://web.archive.org/web/20181106155545/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1229
    archivetier 2retrieved 2018-11-061 fact on this page
  8. 8
    Internet Archive
    https://web.archive.org/web/20181106155532/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1227
    archivetier 2retrieved 2018-11-061 fact on this page
  9. 9
    Internet Archive
    https://web.archive.org/web/20181106155526/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&ETA_1223
    archivetier 2retrieved 2018-11-061 fact on this page
  10. 10
    Internet Archive
    https://web.archive.org/web/20181106115552/http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&a0&2uswk&Bulova_8BA
    archivetier 2retrieved 2018-11-062 facts on this page
  11. 11
    Internet Archive
    https://web.archive.org/web/20230902013028/http://ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&Wyler_E1220
    archivetier 2retrieved 2023-09-021 fact on this page