Nathan K Horns Current Tuning (Raised Letter since 2011)
K3H/K3L - D# F# A#
K3HA/K3LA - D# F# B
K3HL - C D# F#
K3LL-CA - C D# A#
K5H/K5L - D# F# A# C D#
K5HL/K5LL - C D# F# A# C
K5HLA Hybr - C D# F# G# C
K5HLB/LL Hybr - C D# F# A C
K5LA - D# F# G# B D#
K5LLA - C D# F# G# B
K5LLLA - C D# F# A B
K5CA-LS - C D# A A# C (C D# A in soft mode, all in emergency mode)
Musical notes of K bells:
#3L....D# (155 Hz)
#2L....G# (208 Hz)
(P0)...A (220 Hz)
#1L....C (261 Hz)
#1.....D# (311 Hz)
#2.....F# (370 Hz)
#3A....G# (415 Hz)
#3B....A (440 Hz)
#3.....A# (470 Hz)
#4A....B (494 Hz)
#4.....C (512 Hz)
#5.....D# (622 Hz)
#5H....E (660Hz) (African 5)
---------------------------------------------
Nathan K Horns Timeline - with thanks to Eric Miller for much of the information.
1950 - Nathan Manufacturing bought by Wegner Machinery Corp.
1977 - First diecast K5 horns instead of earlier sandcasting, screen printed 'Big Tag', Cork gaskets, Bored #2 bell, large bore and base restrictor #5, unmarked "A"s on the #3 & #4 Bells (to tell whether they are 'A' take the backcap off and see if inside the nozzles is machined out to shorten the throat), Wide font 3O1O9, upright 30115L on the manifold.
1978 - O-Ring grooves in bell foot instead of cork gaskets, stamped tag instead of printed. However cork gaskets were still mostly used. 2 bell doesn't get bored down to the correct note and the 5 bell loses the base restrictor.
1979 - Tagless manifolds appear. Manifold foot lettering changes from 'Airchime' to 'Air Chime'.
Early 1980s - Manifold part number - 30115L - appears upside down.
1983-1986 - Stamped A markings appear on the 3 & 4 bells of 'A' horns, then the change from large bore to small bore 5 bell.
1989 - Back cap part number changed from wide font 3O1O9 to the modern narrow font 30109.
1994 - Square cornered serial number tags introduced, at serial number c. 10K.
1997/98 - Change from square corner to round corner serial tags, Serial number 17,226 first round tag K3LA.
2001 - Confirmed 27K serial number, also in the early 2000's the bubble on back cap got smaller, Over the Road editions appear.
2003 - 2-piece sandcast 1L bell introduced into mainstream use, notably for the K5HL GEVO horn.
2006 - Late 40Ks or 50Ks serial change to raised letter models (Airchime on bell sides as well as number). Micro-Precision take-over from Wegner.
2007 - New 1-piece 1L bell diecast. Early 2007 55K serial number confirmed.
2008 - #4 bell bored as proper C note.
2010 - 67K and 73K serials confirmed. Boring of #2 bell starts again to create F# not 'almost G'.
2012 - 85K serial confirmed.
2014 - 100K serial confirmed.
2015 - Back caps changed to the NATHAN AIRCHIME curved letter type around 105K serial , big bubble and wide font 3O1O9 part number are back.
2017 - GE cast K5HL Bells appear.