CH 27-70 Q

About the Patek Philippe CH 27-70 Q

The 2310 is the column-wheel hand-wound chronograph Lemania designed in 1942, and the Lemania piece explains how the same movement came to sit in a Patek and an Omega Speedmaster. Patek took the ébauche, reworked and finished it to its standard, and mounted a perpetual calendar with moon phase on top: 24 jewels, a 60-hour reserve, a slow beat of 18,000 vph, and a 30 mm diameter. The CHR 27-70 Q added a split-seconds mechanism for the ref 5004. It was the last Patek perpetual calendar chronograph on an outside base; the in-house CH 29-535 PS Q replaced it in the 5270 of 2011.

Every reference here is a Grand Complication: 22 in the 36 mm ref 3970 of 1986 to 2004 and 12 in the 40 mm ref 5970 of 2004 to 2011, in yellow, white and rose gold and platinum. Seven are limited editions, and the glossary defines the perpetual calendar.

The CHR 27-70 Q is the split-seconds version, and the CH 27-70 the same base without the calendar in the ref 5070.