The problems centre on inefficient methods used by engineers to make appointments and visit homes in the Wallington area, which is predominantly suburban residential houses.
The results of the pilot are to be used as a blueprint for the full roll- out of the retuning effort in September, just four months before the station is due to go on air in January 1997.
According to the terms of its licence, Channel 5 must demonstrate to the ITC that at least 90 per cent of homes in its broadcast areas can receive Channel 5 without any interference from their video recorders, many of which use an adjacent frequency to transmit pictures to the TV.
The Channel 5 Broadcasting consortium, led by Greg Dyke, of the media group Pearson, and MAI's Lord Hollick, finally beat Virgin, BSkyB and Canadian-backed top bidder UKTV to win the franchise after an acrimonious judicial review in January.
Ian Ritchie, C5B's chief executive, dismissed suggestions this weekend that the pilot was off target. "The pilot retuning programme in Wallington is progressing satisfactorily and is on schedule, thanks to the hard work of all concerned. It is confirming much of our preliminary thinking," he said.
But according to other sources within Pearson, the 22 engineers who started retuning video recorders in 10,000 homes in Wallington in early June were forced to re-examine their procedures after only one week in the field.
It became apparent that the time taken to complete the retuning process, including failed appointments, was longer - and therefore more expensive - than budgeted in the original plan.
Retuning the estimated 10 million TV sets to broadcast Channel 5 on its assigned UHF frequency has dominated all efforts to get the station off the ground.
The original fifth terrestrial channel project, mooted in 1990, was initially put on hold over fears about funding after only one group, led by Thames TV, stepped forward. All other bidders withdrew because revenue projections did not make the huge cost of retuning worthwhile.
During the latest battle with Channel 5 Broadcasting, the losers sought to highlight the conservative cost projections in its bid; the pilot difficulties mean old chickens may be coming home to roost.
The Pearson/MAI estimate for retuning was pounds 50m, or pounds 5.20 per home. The BSkyB/Granada bid, by contrast, estimated the cost at pounds 130m, or pounds 13.50 a home.
The timing of the exercise has also been questioned. C5B has said it will employ 6,000 engineers to conduct the retuning between September and December this year. Working seven days a week, including Christmas Day, each engineer will have to record 13 successful retunings per eight- hour day, or one every 35 minutes.
However if the Government clears Channel 5 to use an additional UHF frequency in certain broadcast areas, it will have 2 million more homes to retune. At this level, engineers will have to conduct a retuning every 29 minutes.Reuse content