Home > Latest News > Moving out of Ch69 > Moving in to Ch38
Moving in to Ch38
It has been confirmed that Ch 38 will replace Ch 69 during 2012. Ch38 is the band 606 - 614 MHz and is currently shared with Radio Astronomy.
Radio Astronomy will vacate Ch 38 by 21 September 2011 resulting in Ch38 being made available for PMSE use over much of the country. Ch38 will be fully available once digital switchover is complete in 2012. Until then Ofcom has provided temporary access to channels 39 and 40 in the areas where Ch 38 is not available.
The diagram here shows how it sits in relation to other services:
Guard bands are included at each end of Ch38 to avoid interference with services in Ch37 and Ch39 to facilitate free-roaming use throughout the UK. Use within these guard bands would need to be coordinated with other services in Ch37 and Ch39 and there would be parts of the country where use could not be allowed.
The Ch38 licence will not specify frequencies, instead licensees have access to all frequencies within the range 606.50 - 613.50MHz shown below:
10 Channel plan
The 10 channel plan below will ensure that all frequencies can operate in the same location without harmful interaction. This plan is a suggestion only; users and manufacturers can devise their own plans that could involve any number of frequencies within the range.
| Channel 38 - 10 channel set ratings | |||||
|---|---|---|---|---|---|
| 2Tx IM(3) and 3Tx IM(3) | |||||
| 25k0 | 50k0 | 100k0 | Risk Index | ||
| 606.600 | 0 | 2 | 2 | 
1.50 |
|
| 607.500 | 0 | 3 | 5 |
2.75 |
|
| 608.150 | 0 | 4 | 2 |
2.50 |
|
| 609.150 | 0 | 3 | 4 |
2.50 |
|
| 609.950 | 0 | 3 | 6 |
3.00 |
|
| 610.550 | 0 | 4 | 4 |
3.00 |
|
| 611.250 | 0 | 2 | 4 |
2.00 |
|
| 612.300 | 0 | 4 | 3 |
2.75 |
|
| 613.150 | 0 | 3 | 1 |
1.75 |
|
| 613.500 | 0 | 0 | 2 |
0.50 |
|
| Score total | 22.25 | ||||
| Average |
2.225 |
||||
In developing the plan we ensured that each frequency is safely spaced apart. However interaction can sometimes occur between frequencies even when appropriate spacing is applied. This unwanted interference can occur when equipment is operated close together in the same vicinity. It is known as intermodulation or “mixing”.
In the real world these unwanted signals appear on or close to the frequencies being used. To help make sense of this we have devised a figure of merit that we have called the “Risk Index”. This is calculated according to the quantity of unwanted signals and their spacing from the frequencies we are trying to use. Closer spacings have a higher risk of causing interference so are given a higher weighting in the sum.
Things to note about Channel 38:
- High power RSL links or Mics/IEM/Data are not licensable within Ch 38.
- Coordinated licences are not available in Ch 38.
- Ch 38 will not be fully available throughout the UK until 2012 and so Ofcom has also included temporary access to channels 39 and 40 in those areas where it is not until the completion of DSO. Licensees are required to use our ‘Ch38 look-up tool’ to check exactly what can be used at their location prior to operation.
Book Online for immediate access to spectrum
Channel 38 look-up
Look-up which frequency range is available in your location.