COTHEN = Customs Over-The-Horizon Enforcement Network.
The original COTHEN was one of the first autoscanning HF networks, using a SELSCAN mode made by Rockwell/Collins. Modulation was based on FED-STD-1045, and used 8FSK with a voice-channel bandwidth. This was replaced by ALE (MIL-STD-188-141).
Recently, use of COTHEN has greatly expanded, especially by the US Coast Guard. It's the busiest US Federal net on HF.
The original net uses these frequencies: 5732, 7527, 8912, 10242, 11494, 13907, 15867, 18594, 20890, 23214, and 25350 kHz, all USB ALE and voice. Stations sound, and also establish link before follow-on voice comms. ALE and voice calls nearly always differ.
More recently other freqs have been added. Mark Cleary has heard 4614.5, 5250, 5909.5, 11222, 13312, and 14582. I can confirm use of these here. Other frequencies are used by COTHEN players, but so far they are not in the same scan.
Identifications come from lists maintained by Mark Cleary and Larry Van Horn/ Tiare Publications.
003 - - - - USCG HC-130J, CG 2003
500 - - - - USCG HC-130H, CG 1500
501 - - - - USCG HC-130H, CG 1501
713 - - - - USCG HC-130, CG 1713
714 - - - - USCG HC-130, CG 1714
716 - - - - USCG HC-130, CG 1716
717 - - - - USCG HC-130, CG 1717
718 - - - - USCG HC-130, CG 1718
720 - - - - USCG HC-130, CG 1720
A23 - - - - CBP/ICE UH-60, Omaha 423
A39 - - - - CBP/ICE AB139 #N139HS
A65 - - - - CBP/ICE UH-60A
A70 - - - - CBP/ICE UH-60A, Omaha 670
A82 - - - - CBP/ICE UH-60A
CBE - - - - USCG Cutter Tahoma (WMEC-908)
CNT - - - - Central Regional Comm Node
CPDST - - Unknown
D01 - - - - CBP/ICE Q400 #N801MR, Omaha 1MR
D05 - - - - CBP/ICE Q400 #N805MR
D07 - - - - CBP/ICE Q400 #N807MR
D08 - - - - CBP/ICE
D14 - - - - CBP/ICE P-3A, Omaha 314
D23 - - - - CBP/ICE P-3B Slick, Omaha 23SK
D31 - - - - CBP/ICE P-3B Slick, Omaha 31SK
D46 - - - - CBP/ICE P-3B #N146CS
D48 - - - - CBP/ICE P-3B #N148CS
D49 - - - - CBP/ICE P-3B #N149CS
D95 - - - - CBP/ICE P-3A, Omaha295
DENPRI - Remote TX, near Denver, CO
EST - - - - Eastern Regional Comm Node
F29 - - - - USCG Falcon Jet, CG 2129
F31 - - - - USCG Falcon Jet, CG 2131
F41 - - - - USCG Falcon Jet, CG 2141, Foxtrot 41
HKW - - USCG Cutter Confidence (WMEC-619)
I00 - - - - CBP/ICE Cessna 550 #N1200N
I08 - - - - CBP/ICE Cessna 550 #N5408G, Omaha 08G
I1L - - - - CBP/ICE Cessna 550 #N6001L, Omaha 01L
I21 - - - - CBP/ICE Cessna 550 #N26621, Omaha 621
I31 - - - - CBP/ICE Cessna 550 #N2531K
I37 - - - - CBP/ICE Cessna 550 #N6637G
I43 - - - - CBP/ICE Beech #N43SA, Omaha 3SA
I4J - - - - CBP/ICE Cessna 550 #N5314J
I52 - - - - CBP/ICE Cessna 550 #N752CC, Omaha 2CC
I63 - - - - CBP/ICE Cessna 550 #N26663Y
I86 - - - - CBP/ICE Cessna 550 #N586RE
IKL - - - - USCG Cutter Tampa (WMEC-619)
J01 - - - - USCG MH-60J, Juliet 01
J03 - - - - USCG MH-60J, Juliet 03
J06 - - - - USCG MH-60J, Juliet 06
J08 - - - - USCG MH-60J, Juliet 08
J09 - - - - USCG MH-60J, Juliet 09
J10 - - - - USCG MH-60J, Juliet 10
J16 - - - - USCG MH-60J, Juliet 16
J19 - - - - USCG MH-60J, Juliet 19
J21 - - - - USCG MH-60J, CG 6021
J24 - - - - USCG MH-60J, CG 6024
J25 - - - - USCG MH-60J, Juliet 25
J27 - - - - USCG MH-60J, CG 6027
J29 - - - - USCG MH-60J, CG 6029
J31 - - - - USCG MH-60J, CG 6031
J32 - - - - USCG MH-60J, CG 6032
J40 - - - - USCG MH-60J, CG 6040
J41 - - - - USCG MH-60J, CG 6041, Juliet41
J42 - - - - USCG MH-60J, CG 6042
J43 - - - - USCG MH-60J, CG 6043
K02 - - - - USCG MH-65C, CG 6502
K11 - - - - USCG MH-65C, CG 6511
K20 - - - - USCG MH-65C, CG 6520
K36 - - - - USCG MH-65C, CG 6536
K40 - - - - USCG MH-65C, CG 6540
K57 - - - - USCG MH-65C, CG 6557
K59 - - - - USCG MH-65C, CG 6559
K60 - - - - USCG MH-65C, CG 6560
K66 - - - - USCG MH-65C, CG 6566
K72 - - - - USCG MH-65C, CG 6572
K75 - - - - USCG MH-65C, CG 6575
K84 - - - - USCG MH-65C, CG 6584
L08 - - - - USCG MH-65C, CG 6608
LNT - - - - USCG CAMSLANT Chesapeake, VA
LPB - - - - Unknown
N01 - - - - USCG HC-114A, CG 2301
N03 - - - - USCG HC-114A, CG 2303
N05 - - - - USCG HC-114A, CG 2305
N06 - - - - USCG HC-114A, CG 2306
N07 - - - - USCG HC-114A, CG 2307
OMNI - - Unknown omnidirectional rmt
OPB - - - - DEA OPBAT, Bahamas
P26 - - - - Unknown COTHEN Rmt
PAC - - - - USCG CAMSPAC Pt. Reyes
PR1PRI - Primary Remote Tx, PR
RDC - - - - USCG Cutter Campbell (WMEC-909)
T42 - - - - CBP/ICE Piper #N9142B, Omaha 42B
T6P - - - - CBP/ICE Beech #N7166P, Omaha 66P
T85 - - - - CBP/ICE Piper #N9085U, Omaha 85U
T91 - - - - CBP/ICE Piper #N9091J, Omaha 91J
T9F - - - - CBP/ICE Beech #N76509F, Omaha 09F
TSC - - - - CBP/ICE Technical Service Center, FL
UHC - - - - USCG Cutter Decisive (WMEC-629)
VAI - - - - Unknown
VM1 - - - - ICE
YWL - - - - USCGC Thetis (WMEC-910)
VY1 - - - - ICE
WST - - - - West Regional Comm Node
Z14 - - - - USCG Sector St. Petersburg, FL
Z15 - - - - USCG
Z28 - - - - USCG
Z29 - - - - USCG Sector San Diego, CA
