THORN 950 CHASSIS

I replaced the Mazda AW47-91 c.r.t. with a spare Mallard
tube of the same type, the only apparent difference being
that it is not fitted with a linearity sleeve. On switching on
however the fusible resistor in the h.t. supply opened. I
assumed that this was due to excessive width, but there’s
insufficient room between the neck of the Mullard tube and
the deflection coils for a sleeve to be fitted. Any ideas?
You can safely leave the linearity sleeve out – the line
linearity should be acceptable without it. The width’ can be
reduced by means of R132. The fusible resistor probably
failed for some other reason. Check the valves in the line
output stage (PL504/PY81) and the harmonic tuning
capacitor C131. The tripler could be faulty, also the scan
coils – see whether the line output stage valves run cool
when they are disconnected. Also check for line drive to the
PL504 if necessary.