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North West Frequency Plan

Why bother to have a plan ?

As you can see by the Cheshire events list things can get very busy even within a single county. Give that radio waves respect no boundaries then there is a requirement for a plan to ensure a fair allocation of frequencies between the various groups in the North West. The aim is that on average every group should be able to carry out RAYNET operations without interference from others.

The band plans as adopted from 1st October 2006 are :-
 

Mode is FM unless stated otherwise UHF 1/ 70cms VHF MID / 2m VHF LO / 4m Band 1 / 6m  HF /10m HF / General
Cheshire 433.725 145.200 70.3500 51.7500 Frequencies as per individual situation. Frequencies and modes as per individual situation
Cumbria 433.725 (Note1) 145.200 70.4000 51.7500 Frequencies as per individual situation Frequencies and modes as per individual situation
Greater Manchester 433.700 144.625 70.3500 51.6500 29.6800 SSB ( lsb ) 3.6300, 3.6245,1.9050 CW 3.5950 10.1150 
Isle of Man 433.700 144.6125 70.4000 51.6500 Frequencies as per individual situation Frequencies and modes as per individual situation
Lancashire 433.750 144.775 70.4000 51.7700 Frequencies as per individual situation Frequencies and modes as per individual situation
Merseyside 433.775 144.650 70.3500 51.7900 Frequencies as per individual situation Frequencies and modes as per individual situation
Common or reserve Channel. 432.775
In-band UHF 1.6Mhz split Base Tx freq.
145.225 70.3750 ( FM and AM ) No allocation
Frequencies as per individual situation As above - see also National Frequencies at  www.raynet-hf.net

Explanation of Bandplan notes

  1. Cumbria reserve 433.7000 MHz for link comms with the Isle of Man. Other link frequencies in this band as determined by site situations.
FM Standards

At the present time these can vary significantly, depending upon which band(s) you are using:
 

430 ( 70cms ) 5kHz Max Deviation 25kHz Channel Spacing
144 ( 2m ) 2.5kHz Max Deviation
12.5kHz Channel Spacing
70 (4m) 2.5kHz Max Deviation 12.5kHz Channel Spacing
50 ( 6m ) 1.5kHz Max Deviation 10kHz Channel Spacing 
29 ( 10m ) 1.5kHz Max Deviation 10kHz Channel Spacing

PLEASE NOTE - That when you move from 25kHz to 12.5kHz spacing on 2m due to the IARU changes, YOU MUST ALSO HALVE YOUR DEVIATION - otherwise users on the adjacent channels will suffer interference, because your 5kHz wide deviated signal spills over into their channel ! You should reallyu have been doing this from 1st Jan '98 anyway ! Users of Dual-Band sets may therefore find that they have the same standard on 70cm as well, with twice as many channels!

Data on VHF & UHF

When using data on VHF & UHF, it is generally suggested that the deviation is set to approximately two-thirds of the normal speech deviation on the band(s) in question. In practice one will often find that too much deviation causes the data to be corrupted, which will soon be evident in unsuccessful attempts at Packet connects.

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