"piero soldi" wrote in message
...

"Ralph Cameron" ha scritto nel messaggio
...
Steve:
Most Tek scopes used an orange filter to view the trace.
I may have one from an old Dumont scope if you want to
email me offline.

Ralph ve3bbm at RAC.ca
replace the "at" with the appropriate

"Steven Swift" wrote in message
...
According to my DuMont handbook of CRTs, a yellow filter
can be
used with a P7 phosphor CRT to allow viewing of the long
decay
part without being "blinded" by the bright blue trace.
I've searched
Ebay, Sphere Research and other sites looking for these.

Anyone have one good for a 3" round CRT or know of a
good substitute
material (perhaps from a hobby store)?

TIA,

Steve.
--
Steven D. Swift, ,
http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington
98155 USA


Steven, any photographic deep yellow filter will do.
May be you can find a Kodak, Ilford, or Agfa or similar
brand yellow acetate or gelatin filter.
If you cannot find a deep one, use two filters.
Ciao, Piero

Another possibility is to use the filter materials made
by Roscoe for photographic lighting. These are sold in large
sheets and come in many colors. They are not expensive. The
idea of the yellow filter is to suppress the bright blue
initial fluorescence of the screen and it should not take
anything too special to do this.
Roscoe is at: http://www.rosco.com/us/ There is a list
of retail stores at the bottom.


--
---
Richard Knoppow
Los Angeles, CA, USA