Technique for replacing 6L6/5881 o/p valve tubes

[N_Cook]

I have large hands, how do people with small hands/short fingers do it?
Just managed to break the top of one of these bottles. I thought I used the
right tecqniue but failed here. Sovetek, GT badged bottles , instead of
domed top, nominally flat with a bit of a central pip.
Come replacing I go in the sequence , along the line of 2,4,or 6 sockets,
that allows a full finger each side of the dragon's teeth grips to depress
while pushing in the bottle. Then I place with top of the valve in my palm
and push down on the ledge area of the top of the bakelite base, with finger
tips. Doing so , the palm of my hand is barely touching the top but enough
pressure on this pip to induce failure. As such a light force , I assume it
was likely to soon fail from vibration & temp cycling. Failed in the ring
around the flat area.

Next time I see flat tops (flat not compatible with vacuum) I will cover
with a temporary grommet, before replacing, any other experiences/tips?

Perhaps change technique to making a yoke to push down on the spring
retainers , using chest , forehead or chin or something, and then use four
fingers on the base to press into the socket. Or some sort of chassis clamp
to depress the clamps. Then two fingers, unless a weakened socket, is not
enough pressure to overcome the resistance

 

[N_Cook]

Or ignoring the scratch marks made on the base , and push in with 4 fingers
on the base, after all it is only cosmetic damage.

 

[N_Cook]

'Stubborn' ones get helped out of their sockets with a small flat bladed
screwdriver between the valve and socket. New ones are fitted with a
standard yellow cloth duster on the top and palm pressure. I don't let the
scratch marks from the retainer claws bother me ...

I can't recall ever having had one break on me in the way you describe.

Arfa

I don't remember seeing these sort of central pips before (on that end),
either domed or flattish.
Next time I will have a couple of strips of PTFE looped around the dragon's
teeth and push in with 4 fingers around the base. Then releive each spring
in turn to retreive the PTFE. If that does not work then have to make up
some sort of spring compressor or let them goiuge away.
It's just that years ago I came across an amp that the owner loved rotating
the bottles about and the bakelite was a real mess, barely functional