🚀 go-pugleaf

I bought my first IR conversion tube from Fair Radio Sales in Lima,
Ohio a few yeasr ago for maybe $10, call information in Lima for their
number, they might still have some. 
 
I have since seen various types at C & H Sales for a bit more, I think
they are located in Pasedena, CA. For a while they also had a good
deal on IR filters, charging $3 or $5 for the nice big ones everyone
elses wanted $20 for. Maybe they have more.
 
You do know that these "first-generation" tubes require a 5-20 KV
anode voltage and a 2-10 KV focus voltage, and have pretty poor image
quality, don't you? I have yet to see 2nd generation
microchannel-plate based tubes go for less than a few hundred.
 
A very good alternative you might want to look into is using a video
camera. I believe the type you want would be a CCD type. There was
much discussion on Steve Ciarcia's Circuit Cellar BBS about the
infra-red sensitivity of these devices a while ago. It may well be
that those cheap DAK video cameras are of the proper type. Putting an
IR filter in front of one will make it sensitive to only IR. Just walk
into a home electronics store and point an IR remote control at a
camcorder when a salesperson isn't looking for a good demo.

-cornhead