Among the feverish pre-Christmas sales of mobile phones, a newcomer, Dancall Telecom A/S, subsidiary of UK personal computer maker Amstrad Plc, is doing well in the UK, France and Czech Republic. Czech dealers, for example, say Dancall is number one on the Czech market, accounting for approximately 70% of GSM Groupe Speciale Mobile sales. UK dealers, meanwhile, say it is gaining ground, being number two on the Orange network, after Nokia Oy. Amstrad apparently purchased a bankrupt Danish company called Dancall Radio in Copenhagen. Sources say that the 100% Danish-manufactured phones have a good price/performance ratio, even if they are not sold at exceptionally low rates.