Re: yoke resonant frequency

>I really think some type
>of audio chip should be able to handle deflection in the XY monitors.

I tend to agree, but the yoke makes a big difference. The example monitor
that I have (using the STK0050 audio amps to drive the yoke) has a notably
different yoke than the 6100 or GO-8. It has a *lot* of turns of fine ga.
wire instead of relatively few turns of the thick wire on the WG or
Electrohome versions.

So if we're starting to get serious about making a new monitor what would
the steps be? I'd be inclinded to start like so:

1) pick a tube. Should be cheap, available, relatively dark, relatively
flat, and have full specs available.

2) Knowing the tube type defines your voltage requirements to a large
extent. The HV section can be designed at this point, with the neck board
in mind too (to drive the color guns). The HV should use an easy to
find/cheap flyback and other common magnetics and transistors.

3) Design the yoke/deflection amps. It would be nice to design the yoke to
be as simple as possible to make, since someone will likely have to
hand-wind it. Anyone know of a place to buy the "bare" yoke collars?
Alternatively using a WG or Elect. yoke is nice for testing, but might be
tough to come up with any significant number of them. Deflection amps
should be designed for stable operation and reliability with as common of
parts as can be found. (Try to avoid anything that's already obsoleted or
single-sourced. ;-)

4) Low voltage supply. Should be pretty straighforeward given the power
requirements of the above boards. Something using standard 78xx or 79xx
type parts would be good. Linear is probably OK since switchers add
complexity.

Bonus Points for:

Have the power, deflection and HV sections drop into an existing 6100 or
GO-8 with a minimum fuss to replace the existing boards.

I like Zonn's idea of taking the standard TV and reworking it, but TV
models change so fast it'd be kinda tough to make a definative document on
what to do. (6 months from now the TV's off the market and we're having to
buy a new $300 TV every time to re-design the modifications.)

I for one would give up some of the "cheap" goal in exchange for readily
available parts, good reliability and good picture quality...

-Clay

Clayton N. Cowgill Engineering Manager
_______________________________________________________________________
/\ Diamond Multimedia Systems, Inc. clay@supra.com
\/ Communications Division http://www.supra.com/
Received on Wed Sep 3 10:42:13 1997