I never did get the Spectrum Communications Off-Air Frequency Standard kit working. Now it is looking as though it would be a waste of time anyway as the BBC will be closing down the Radio 4 long wave transmitter that is used as a frequency standard.
An article published yesterday in the Guardian Online explains that the Radio 4 long wave transmitter uses valves (tubes) that are no longer obtainable. The BBC has the only ones still in existence. The transmitter uses a pair and they can last as little as one year. When the last valve blows, Radio 4 on long wave will become a thing of the past.
Building a new long wave transmitter using up to date technology would cost millions which the BBC can no longer afford due to the need to cut costs as a result of the government's decision to freeze the licence fee.
There are many other ways to receive the Radio 4 programming if the long wave transmitter closes down. But none of them involve a powerful 500kW transmitter whose frequency is maintained accurately enough to be used as a frequency standard.