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Smarty

On 6/2/2013 3:14 PM, wrote:
On Jun 2, 12:15 pm, Smarty wrote:
On 6/2/2013 7:23 AM, John-Del wrote:

On Saturday, June 1, 2013 4:54:09 PM UTC-4, Smarty wrote:
"William Sommerwerck" wrote:
Sounds like a purity problem. Start by degaussing it.
A purity problem would NOT have black and white looking ok as reported in
the original post nor would it result in explicit color replacements as
reported.
Not true. Purity problems are most apparent when the chroma is on. If one looks carefully, the purity problem does exist in the black and white image, but it's just no where near as apparent.
Sounds like a color demodulation problem.
A color demodulator problem would cause incorrect colors, but I've never seen one cause localized errors as the OP pointed out.
Most likely the dual degaussing thermistor is either bad, or has one lead detached from the board.
I have not dealt at all with magnetized Trinitrons / aperture grills,
and only have very limited experience with magnetized conventional CRTs
but purity problems certainly were visible in the black and white images
of those needing degaussing. It did not take moving color images to
suggest purity / magnetization nor did it take careful inspection. The
other, even more confusing original post issue was the non stationary
nature of the color shifts, and the fact they were reported as moving
with the displayed image, again evidence that the problem was not a
purity problem.

I gladly defer to the experience and judgement of those who repair TVs.
My experience is limited to building a Heathkit color set a million
years ago and repairing my Advent and Kloss projectors, not using or
needing any purity control whatsoever!- Hide quoted text -

- Show quoted text -
Hats off to you for building one of those early color tvs. I hated to
see Heathkits close up. Do you remember how they started with kits
for airplane builders? The electronics came a little later. I still
have some instruction manuals for some of their early kits that I
built in the 1960s. Had my wife(to be) help me with reading some of
the resistor color codes as I am partially RG colorblind
I do remember the original catalogs showing airplane related kits, but I
did not get into it really until the late 1950s. I guess I became a
Heathkit maniac. I built nearly 50 kits starting in the 1950s and ending
in the 70s as I recall. The ham radio stuff was the earliest (DX20,
DX40, Apache, SB-1 Single Sideband Adapter, SB101 transceiver, SB200
kilowatt amplifier, Q multiplier, KW Compact mobile amplifier, SWR
bridges, wattmeter, phone patch, two meter and UHF rigs,......), test
equipment (scopes, signal generators, a couple VTVMs, a couple digital
VOM / DMM meters / frequency counter, decade capacitor and resistor
boxes,), all sorts of tube and then solid state audio equipment, a
25inch color TV (for my parents), lots of electronic gadgets like
digital clocks, indoor outdoor thermometer, digital platform scale, grid
dip meter, "Cantenna", weather stations, and on and on.

I am also saddened to see the era of electronic construction fade away.
No doubt the deterioration of American leadership and expertise in
"building things" is a bigger and related source of disappointment for
those of us who remember this period fondly, and have deep concerns for
our kids and grandchildren.

The Heathkit appeal for me personally wore out as I began to do my own
designs and finished my engineering program. I got heavily into digital,
gave up ham radio (except for radioteletype RTTY), and began buying more
advanced audio and video stuff. My basement in my parent's home looked
like a cross between a wholesale electronics parts supplier and a messy
teenager's bedroom.........

Very little of it came with me when I got married and moved out. I
presume my parents must have given most of it away except for the very
few things I took with me. I still have one remaining Heath item only,
an indoor outdoor digital thermometer, which I wound up modifying to
control my hot tub water temperature nearly 30 years later!