2.4514 Mc, 2.4674 Mc, and 2.4834 Mc

[Nigel Holmes 03 9626 1914 fax 03 9626 1917]

Hello Jeff,

Where did those frequencies come from? - I'm not sure that they are
allocated to maritime mobile except for limited use in ITU region 1 with
2262.5-2498 kHz available for intership SSB telephony (RR 4188).

2300-2495 kHz is allocated to domestic broadcasting in the tropics in all
three ITU regions (RR406-411). In regions 1 and 3 "tropics" is
approximately the area between 30 deg. N and 35 deg. S. In region 3 it is
between the Tropics of Cancer and Capricorn.

(Australian broadcsating examples are VL8A Alice Springs on 2310 kHz,
VL8T Tennant Creek on 2325 kHz and VL8K Katherine on 2485 all between
0830-2130 UT with 50kW carrier into dipoles. Modulation is held to a
maximum of 75% to give protection against selective fading effects. These
could be good markers for low band propagation as the high angle of
radiation is more typical of what most amateurs can do on 160m compared
with the low angle radiators used by 520-1600 kHz broadcasters.)

Fixed and mobile services also operate in 2300-2495 kHz, but the
broadcasting service has priority over these within the defined tropical
regions (RR2671) and outside these regions non-broadcast stations may
operate on a non-interference basis (RR346), which is the same regulation
that allows amateurs to work in 7100-7300 kHz. These days "fixed
services" is usually a euphemism for military stations.

The general spectrum allocations to maritime mobile around 2 MHz are
2045-2160 kHz in Region 1, 2065-2107 kHz in Regions 2 & 3, 2170-2173.5
(1, 2&3), 2190.5-2194 (1,2&3). 2194-2300 kHz (1,2&3) is available but
shared with other fixed and mobile users. 2173.5-2190.5 is the guard band
for 2182

USCG has a good web site describing the various marine channel
allocations in USA. For 2 MHz look at

http://navcen.uscg.mil/marcomms/rtchan2.htm

Hope this helps.

73 Nigel  VK3ZNQ