Will any 2804-X mainspring fit into a 2804-2 movement?

[Watchnoob2]

I will replace the mainspring in a 2804-2 movement. Do I need a 2804-2 mainspring or will any 2804-X mainspring work?

Bonus question: If possible to answer - what kinds of differences are normal between movements with the same base number? (like 2804, 2804-1, 2804-2 and so on).

Thanks in advance.

[JohnR725]

If you look at the links below your 2804-2 is part of the 2801 family. Which includes both manual wind and automatic. The automatic of course will require a mainspring for an automatic watch. Then for the 2804-2 I have a list of all the watches which use the same mainspring. Basically it looks like all of the non-automatic watches use the same mainspring.

70/169
 MAINSPRING, 1.25X.125X16-3/4
 GR 3149

 ETA 2801      28,800 BPH STOP DEVICE DSS.
 ETA 2801-1      28,800 BPH-DSS-STOP DEVICE-W/OR W/OUT SEC
 ETA 2801-2      28,800 BPH-DSS-OR W/O SEC-STOP DEVICE-
 ETA 2802      21,600 BPH DSS CALENDAR W/CORRECTOR
 ETA 2804      28,800 BPH DSS CALENDAR W/CORRECTOR
 ETA 2804-1      28,800 BPH-DSS-CAL-W/CORR-WOR W/O SEC
 ETA 2804-2      28,800 BPH-DSS OR W/O SEC.-CALD.
 ETA 2805      28,800 BPH DSS CALENDAR W/CORRECTOR
 ETA 2806      36,000 BPH DSS CALENDAR W/CORRECTOR
 ETA 2807      36,000 BPH-DSS-CALENDAR
 ETA 2810      28,800 BPH DSS CALENDAR DAY DATE W/CORRECTOR
 ETA 2811      28,800 BPH-DSS-CALENDAR DAY-DATE W/CORRECTOR
 ETA 2812      36,000 BPH DSS CALENDAR DAY-DATE W/CORRECTOR
 ETA 2813      36,000 BPH-DSS-CALENDAR-DAY-DATE W/CORRECTOR
 ETA 2816      28800 BPH-DSS-CALD DAY/DATE W/CORR STOP
 ETA 2816-1      28800 BPH-DSS-CALD-(DAY-DATE) W/CORR.
 ETA 2817      36000 BPH-DSS-CALD DAY DATE W/CORR STOP
 ETA 2819      36,000 BPH
 ETE 12824      28,800 BPH DSS AUTO CALD
 TIS 3051      28,800 BPH STOP DEVICE DSS.
 TIS 3052      BPH 17JL DSS CALD W/CORR

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_2804

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&ETA_2804_2

 

[Watchnoob2]

Thanks a bunch!