[R-390] PEARL Tube Coolers

[ToddRoberts2001@aol.com]

Hi All, Dave Ross's recent question reminded me that I wanted to ask the 
group if anyone has had any experience with the PEARL tube coolers? I see they are 
popular with some of the Hi-Fi crowd. Supposed to be even better than the 
IERC type shields at dissipating heat. They look kind of like a flexible 
accordion tube that slips over the glass envelope and snaps tight with rubber O-rings. 
The black accordion-like ribs act like small fins to dissipate heat away from 
the glass envelope. They are not designed to electrically shield the tubes 
but I have read that most tubes in the R-390A do not require electrical 
shielding or grounding of the shield. Thanks for any comments! 73 Todd Roberts WD4NGG.