On Jan 17, 12:49 pm, spamhog wrote:
On Jan 17, 12:48 pm, Chuck Harris

No, but don't let that stop you from trying it anyway.

-Chuck

:-) What keeps me is the fact that I have no idea how I could measure
the core temperature in a tube!

Is heater current temperature-dependent enough as to provide a proxy?

Hints anyone??

This test was done using a Raytek laser digital thermometer.
Temperatures
were taken from a 6BZ6 1st RF amp tube on a John R. Leary SP-600JX no
suffix
number, serial number 1262. Ambient room temperature was 75°F. I'm not
a
scientist nor should this be misconstrued as a scientific test. I
have
always been curious as to whether the IERC tube shields "actually"
prolong
tube life. As noted there were several different tube shields used in
this
"test." Also note there are several different types of inserts inside
these
tube shields.

The bare tube bulb temperature was "shot" immediately after removing
the tube shield.

The "Real McCoy" IERC Tube Shields have a finger grip type of insert
that
acts as a heat sink and the test results show that the temperature
difference between the shield and the tube itself is little. That
should
tell us that that type of shield is the "Standard." For your
information, I
don't use tube shields and my tubes seem to last a long time.


Take this information as it's meant to be, strictly informational.


1.. Shiny metal Eby tube shield no insert. 94°, bare tube 124°F.


2.. Shiny metal Eby tube shield with seven-sided black aluminum
insert.
96°F, bare tube 127°F.


3.. Dull metal Elco tube shield no insert.108°F, bare tube 135°F.


4.. Black heat resistant painted Eby tube shield no insert. 104°F,
126°F
bare tube.


5.. Black anodized Eby tube shield with "waveform, nine ridges"
aluminum
black heat shield insert. 107°F, bare tube 127°F.


6.. Collins black anodized tube shield with "waveform, nine ridges"
aluminum black heat shield. 100°F, bare tube 122°F.


7.. W.P.M. tube shield with five-sided aluminum insert. 106°F, bare
tube
118°F.


8.. IERC tube shield with "finger grip" type beryllium insert. "The
Standard." 102°F, bare tube 104°F. ( has to be the insert)


9.. Bare tube, no shield. 6BZ6 114°F.
YMMV