|Background to the project|
Isle of Man has been served by two co-located repeaters for many years
(at least twenty to my recollection, and certainly more than that).
During that time technologies have changed and appeared which make it
possible to greatly enhance the effectiveness of our repeaters,
particularly with regard to coverage of the Island itself.
One often cited shortcoming of the Snaefell repeaters is the fact that, whilst the location offers superb coverage of the Irish Sea and surrounding lands, it often fails to provide adequate coverage of its immediate surroundings.
This leads to the situation where off-island stations enjoy excellent service, whilst on-island stations often struggle to be heard.
An additional drawback of Snaefell is ease of access. The only motorised access to the summit is either by means of the Manx Electric Railway, which is operated only during the summer season, or by "hitching a ride" with the Civil Aviation Authority's on-site engineers in their Diesel-powered rail car. Again, the CAA staff only visit the site on a few days in the week.
all other times, the only other access to the site is by walking - not
an enticing prospect when you're carrying tools and test equipment.
keeping Snaefell on the air is highly desirable, the group feels that
additional, supplementary, coverage is needed in order to maintain
communications if the site should be lost for whatever reason (Weather,
power failure, antenna fault etc). Furthermore, it is felt that
Snaefell alone does not provide adequate coverage of the island.
project was first floated at a meeting of interested parties in
December 2007. This discussion re-inforced the already well-known views
of many local amateurs that we needed to become less dependent upon
Snaefell as our primary repeater site, and that infill coverage of
major communities was required.
During the following year, various technical discussions were held with the Emerging Technology Co-Ordination Committee (ETCC) of the RSGB to determine whether we might be permitted to achieve our aim of providing greater coverage of the island by using multiple internet-linked repeaters.
As it turned-out, once the ball had started rolling it quickly gathered momentum. The ETCC were keen to encourage this project, especially as the design deliberately avoided extending the coverage of the repeater beyond the island's boundaries.
The question was asked, and was quickly rejected, as to whether we could do anything on 2 metres. One of the reasons for rejecting 2M was the absurdly high price of duplexers but, additionally, recent studies by the ETCC have determined that new proposals for this band will not be readily accepted.
Once it was agreed that 70cm was the way to go, the ETCC were exceptionally helpful in moving things along at breathtaking speed.
|The initial plan is as
The primary node for the project is located at the Carnane Radio Site (GB3IM-C), located south of Douglas. This node will house the main computer hardware and the primary internet link.
Snaefell will be reconfigured to be a secondary node, triggered by an uplink from Carnane.
A third node will be added in the North of the Island to provide infill coverage in areas tradionally poorly served by Snaefell because of terrain screening. The site is about 3 miles north of Ramsey and is designated GB3IM-R. This node will be internet linked to Carnane.
Carnane and Ramsey (GB3IM-C and GB3IM-R) will operate on wide-spaced channel RU66 (Output: 430.825MHz, Input: 438.425MHz). Snaefell will remain on RB5 (Output: 433.125MHz, Input: 434.725MHz)
|Manx Repeaters Home||Mail Us|