I have an electrical engine analyser originally from the US. The id plate states 120V, 7A, 60Hz. I was planning to use a site transformer, 240v to 110v, 3.3kva however will there be an issue with the 110v versus the specified 120v and also I'm assuming the transformer output will be 50Hz so will this be an issue also as the unit is specified as 60Hz ?. The unit has a CRT oscilloscope and analogue gauges therefore has to operate with accuracy to be of any use.