The noise issue is most likely to be a problem if you try using one of the "el cheapo" switching converters instead of a proper transformer. Personally, I would advise against using the transformer-less converters for anything, and certainly not for electronic equipment. Get a decent transformer of the correct size -- You'll pay a few bucks more but you won't have any problems.
Some more suggestions, from this side of the Atlantic:
http://www.newmarket-transformers.co.ukhttp://www.airlinktransformers.comNo, the iH5 radio section is designed only to receive AM/FM signals in the United States.
I assume that the digital tuning on this unit stops only on the assigned broadcast channels, as is common on many modern sets. The problem with this arrangement is that the U.S. and U.K. channel assignments are different.
On AM, the U.S. has 10kHz spacing -- 900, 910, 920, 930 etc. The U.K. uses 9kHz channels -- 900, 909, 918, 927, 936 etc. -- so only a few spots on the dial coincide with U.S. assignments.
On FM, American channels are on 200kHz spacing, always ending in an odd digit: 89.7, 89.9, 90.1, 90.3, 90.5 etc. Some U.K. FM stations use the even slot -- 90.2, 90.4 etc. -- and a few are even on 50kHz spacing, e.g. 90.15 MHz.
You'll find that you can receive some stations fine, some will be audible but not very clear as you'll be a little off-tune, and some will be completely unlistenable.