After a burnt out PL81 and R56 have been replaced, also a low valve four, 1 have a blank screen. All valve heaters are alight, also the tube. The line whistle is heard after about a 90
seconds time lapse and can be varied by the line
hold control. The EY51 has also been replaced and a large spark can be got from its anode, also
the tube anode gives off a good spark, this anode
giving off a sizzling sound. Also the ion magnet fibre strap broke and I fixed this with a brass
rivet and replaced magnet more or less in the same position. I have tried the tube as a triode, connected as given on page 165, November, 1956, but still no sign of a raster. Sound is quite loud
and is varied by the contrast control. -L. R.
Whittaker (Mansfield -Woodhouse)
We note that you have replaced the ion trap magnet -” in more or less the same position.” The setting of this magnet is absolutely critical
upon its initial setting up. We must assume, therefore, that you have not found the correct
position for this. If there is a line on the tube
neck align the magnet to this slightly in front of
the base with the arrow pointing forward.
If there is no line, one may be imagined which
would come into line with the position reserved for pin 3 on the base (this is not actually fitted).