[Coco] An open letter to the coco community

[CoCoList for Color Computer Enthusiasts]

Hi Roy!
That is a great blessing for those of us who are finding it very hard to get employed again.  A month or so ago I bought a first edition version of your converter from a coco list member in Canada that worked perfectly the first time I tested it on about a 15" flat screen monitor.  I tried it again last week or the week before and the display slowly flashed on, off, on, off, etc.  Any ideas as to why?  I was testing a 512KB Simm Memory Upgrade PCB I made for a friend using my test Coco 3.  I'll try it again on my normal 512KB Coco 3 setup I routinely use and see what happens.  I'll let you know the results.  Thank you again for your generosity.  I may need to take you up on your offer.  Take care my friend.  
Kip

---- CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com> wrote: 

=============
Friends,
I am writing this  letter to address the problem of the cost
of producing my  converter.   Since I have retired I have the time
to accommodate  everyone.  Also my full pension kicked in this
month so I don't need the  money.


The cost to build the units is  approximately $120 USD.
Isn't that ridiculous?    So this is  my proposal.    I am going
to ask $200 per unit for my  converter to those who can EASILY
afford it.   But if you can't, I  will accept any amount you can
comfortably manage, even if is  nothing.   What is the reason
for this policy  change?    Because the old low frequency 
CRT''s are  disappearing fast.   I have fixed enough of the older
TV's in my  time to realize they have a fatal design flaw and
Gene can probably back me  up on this.    The deflection
yoke coils are driven by the  horizontal and vertical oscillators
They are heavily stressed by high energy  magnetic fields.
This causes excessive vibration and heat in  the
coils.   I have found that this combination carbonizes  and
removes the enamel insulating the wire of the coils causing the  coils
impedance and resistance components to drop which
overloads the  H.O.T. (horizontal output transistor) leading
to catastrophic  failure.   If you just replace the H.O.T. it
immediately fails and  usually you cant see the problem because
the damage occurs on the inside of  the coil where it makes
sharp turns in direction.   Since the TV is  old good luck
finding another yoke coil which is a shame because the  rest
of the unit is in pretty good shape for its  age.

Soooo.......it is imperative  something be done to address 
this problem and I am in a unique position to  invest the time
and up front money to make a modern LCD monitor  available
to every CoCo enthusiast.     

Now my converter isn't perfect.   It  actually does too good
of a job rendering the signal.    There  is broadband noise coming
out of the GIME chip.    The green  signal is perfect.   The red
signal is slightly off and the pure  blue signal is so out of line
as to make the text difficult to  read.   The old slow CRT's did
a lot of natural filtering and of  course Radio Shack took full advantage
of this by ending development when it  was just good enough for
the CM-8.  I have addressed the problem  somewhat by adding both
input and output low pass filters to the  unit.   Its not a perfect
solution but it does help  a  lot.

Anyway , I figure with the caliber of  people in this group I will probably
break even or close to  it.

I also figure I can turn out 3 units a week  working at a leasurely
pace.

So there  it is friends.   My life's mission is set before me.
I probably  won't get bored anytime soon.  :)))

Roy


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