On 12/08/2011 23:29, Robert Seely wrote:
Hello, My apologies for the intrusion. but I have a question that I
am
hoping someone has an answer to. I have never posted to a news
group,
so again, my apologies if this does not meet the standard protocol.

I have a bunch of Raytheon Subminiature tubes that I inherited from
my
Father, who was an electronics bugg (I followed a different path)
that
have code QF-721. In searching the internet I have found a bunch of
identical looking tubes such as one labeled CK6088. I have done lots
of searches on the internet and I cannot find out anything about
these
and am wondering if you know about these, or if you can point me to a
website that might shed some light on these.

I am considering the possibility of donating these to someone but if
I
cannot find out what they are for, I cannot imagine how I can find
who
to donate them to -- perhaps a school or something.

Robert,

I've seen these over here in the UK, although they were made by Mullard
and had type numbers like EF731, 734, etc. I believe they were known for
a while (at least in the UK) as "deaf-aid valves" as they were used in a
body-worn amplifier for a ear-insert hearing aid. I came across them in
a radio-navigation system made back in the early 60s where they were
used for RF and IF stages up to about 3 MHz.

HTH

'BF