Andy wrote:

I found a review from Radcom on the net and it sounds good.
http://www.mixw.co.uk/product/reviewAA200.htm I sent an e-mail to the
designer of the Analyser and he says it does not require re-calibration.

That feature is a two-edged sword. On the one hand, it means the
analyser is immediately ready for routine measurements. That of course
is a good feature for most of the users, most of the time.

On the other hand, if it doesn't have the *capability* to be
recalibrated when different kinds of test fixtures are attached, it
means that some useful kinds of measurements will not be possible... or
worse, will appear to be possible but may give wrong answers.
Measurements of the resonant frequencies of coaxial chokes are an
example where analysers that cannot be recalibrated will give large
errors - see the last few paragraphs of:
http://audiosystemsgroup.com/RFI-Ham.pdf

There's a place for both the simple handheld analysers and the ones that
have more features but live on a bench. It's the buyer's choice... but
whichever one you buy (or build) first, you may eventually find uses for
both.


--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek