[R-390] microphonic 5749W

[Tim Shoppa]

Scott Bauer <odyslim at comcast.net> wrote:
> FYI, I have been using 5749W's made by Phillips on a
> 1986 contract. I have 100+ and am having micro-phonic problems
> with them in the PTO and a couple spots on the R-390A IF strip.
> They work fine for the first 20 or 30 hours then go micro-phonic.
> These are the tubes with Phillips written in blue ink.
> If you should see these at a hamfest, don't buy them.

I have many of these (along with lots of other JAN 6BA6's/5749W's)
I think and I have never really noticed microphonic problems. 
I'm starting to think that you're much more picky than me :-).

Mine say "JAN 5749W Philips ECG 34167 USA" with stamps like
"8726 ADE for date and ?plant?" etc, blue lettering. They often
show up at hamfests etc.

Tim.