"Peter Parry" wrote in message
...

There is a semiconductor surge suppressor fitted with similar
performance to the gas discharge types.

The CPC supplied units are manufactured by Pressac.

I had a look at their site -notable for its scant information- and
noticed that the semiconductor surge suppressor you describe appears
to be their standard fitting for 'voice products' instead of the old
gas discharge devices.
Illustration of LJU 2/1A so fitted.
http://www.presscomm.co.uk/products/...ic=prd-281.gif
Presumably has BT approval.

In my CPC NTE5 (CTE5) sample the semiconductor surge suppressor fitted
is manufactured by Littelfuse(Semitron) with part number has part
number T10A180E.
http://www.littelfuse.com/cgi-bin/r....9&PartID=14783

This 68K pdf covers the series, T10A, with other ratings:
http://www.littelfuse.com/data/en/Data_Sheets/T10A.pdf

So it looks like the end for the old gas discharge devices?

Roger