Ideally identifying which and dismissing the roady would make more sense for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as retainers
in inverted amps. Lining the holes in the chassis where the valves pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies and
white cap.
I am thinking of running my plaited, high temperature silicone cord "rope",
over the tops of all 6 of these small valves , located over the top "pips"
and anchored to the chasis at the ends.
Any comments pro or con ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:
Ideally identifying which and dismissing the roady would make more sense for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as retainers
in inverted amps. Lining the holes in the chassis where the valves pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies and
white cap.
I am thinking of running my plaited, high temperature silicone cord "rope",
over the tops of all 6 of these small valves , located over the top "pips"
and anchored to the chasis at the ends.
Any comments pro or con ?

Don't the ecc83`s have screening cans on them? that`s the usual method
of keeping them in their sockets and protecting them.


Ron(UK)


--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

Ron(UK) wrote in message
...
N Cook wrote:
Ideally identifying which and dismissing the roady would make more sense
for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as
retainers
in inverted amps. Lining the holes in the chassis where the valves pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no
obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies and
white cap.
I am thinking of running my plaited, high temperature silicone cord
"rope",
over the tops of all 6 of these small valves , located over the top
"pips"
and anchored to the chasis at the ends.
Any comments pro or con ?

Don't the ecc83`s have screening cans on them? that`s the usual method
of keeping them in their sockets and protecting them.


Ron(UK)


--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com


No skirts around the bases on the pcb or on the chassis so screening cans
were never used on this model.
It would be quite a work up to introduce cans on this.
The chassis holes are about 3/4 inch above the valve bases, perhaps that
gives a certain amount of screening

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:
Ron(UK) wrote in message
...
N Cook wrote:
Ideally identifying which and dismissing the roady would make more sense
for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as
retainers
in inverted amps. Lining the holes in the chassis where the valves pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no
obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies and
white cap.
I am thinking of running my plaited, high temperature silicone cord
"rope",
over the tops of all 6 of these small valves , located over the top
"pips"
and anchored to the chasis at the ends.
Any comments pro or con ?
Don't the ecc83`s have screening cans on them? that`s the usual method
of keeping them in their sockets and protecting them.


Ron(UK)


--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com


No skirts around the bases on the pcb or on the chassis so screening cans
were never used on this model.
It would be quite a work up to introduce cans on this.
The chassis holes are about 3/4 inch above the valve bases, perhaps that
gives a certain amount of screening

Do the bases have those little 'pips' to clip a retaining spring into?

Maybe a decent flight case is the answer, and a more careful roadie!

Ron


--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

On Oct 29, 8:33 am, "N Cook" wrote:
Ideally identifying which and dismissing the roady would make more sense for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as retainers
in inverted amps. Lining the holes in the chassis where the valves pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies and
white cap.
I am thinking of running my plaited, high temperature silicone cord "rope",
over the tops of all 6 of these small valves , located over the top "pips"
and anchored to the chasis at the ends.
Any comments pro or con ?

I think the problem is not retention of the miniature tubes, but the
fact that their socket (some distance under the chassis) obviously was
jarred and shifted/vibrated enough to cause the tube envelope to hit
the chassis hole.

I think that enlarging the hole or stiffening the chassis is your only
choice. Retainers keep tubes in their sockets, but do not stop the
socket from moving under the hole.

Tim.

The old valve TV's used to have a wire clip over the top of the valce
to stop them falling out.

On Oct 29, 7:33 am, "N Cook" wrote:
Ideally identifying which and dismissing the roady would make more sense for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as retainers
in inverted amps. Lining the holes in the chassis where the valves pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies and
white cap.
I am thinking of running my plaited, high temperature silicone cord "rope",
over the tops of all 6 of these small valves , located over the top "pips"
and anchored to the chasis at the ends.
Any comments pro or con ?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/

I had an AC30CC in recently. I don't like how they did that grommet
thing on the preamp tubes. They really don't do *anything* besides
provide damping to the glass envelope. What I would do is enlarge the
chassis holes and put in larger grommets. Make sure the tube can be
worked out of the socket with the grommet in place...don't go too
small. Then the idea of strapping them down with some sort of retainer
isn't a bad idea as long as yer in there.

Ron(UK) wrote in message
...
N Cook wrote:
Ron(UK) wrote in message
...
N Cook wrote:
Ideally identifying which and dismissing the roady would make more
sense
for
this locally based, but made big-time band.
Failing that - concerning cut grommets encircling valves to act as
retainers
in inverted amps. Lining the holes in the chassis where the valves
pass
through .
a/ fairly rigid rubber of otherwise standard trunking grommets
b/ fairly tight to the glass envelopes to function as retainers.
c/ obviously they do no take much a jarr to cause breakage as no
obvious
damage to the cab.

The 4 o/p valves have spring retainers.
One of the ECC83 quite neatly split in a ring where the grommet lies
and
white cap.
I am thinking of running my plaited, high temperature silicone cord
"rope",
over the tops of all 6 of these small valves , located over the top
"pips"
and anchored to the chasis at the ends.
Any comments pro or con ?
Don't the ecc83`s have screening cans on them? that`s the usual method
of keeping them in their sockets and protecting them.


Ron(UK)


--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com


No skirts around the bases on the pcb or on the chassis so screening
cans
were never used on this model.
It would be quite a work up to introduce cans on this.
The chassis holes are about 3/4 inch above the valve bases, perhaps that
gives a certain amount of screening

Do the bases have those little 'pips' to clip a retaining spring into?

Maybe a decent flight case is the answer, and a more careful roadie!

Ron


--
Lune Valley Audio
Public Address Systems
Hire Sales Maintenance
www.lunevalleyaudio.com

I can really only probe through the chasis holes but the bases seem smooth
sided.
I won't be desoldering wires etc to remove the pcb when all else is fine.
I've made a mounts to one bolt for each transformer , remove all 6
grommets and tie down the valves using the glass-melt-draw pips on the valve
tops.
I usually use this plaited silicone cord or sleeving to stop a line of
emiter resistors (well split into 2 so there is a joint to anchor to) from
vibrating in combo amps .


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/