Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and information about some of the electronic, electrical and electrotechnical Obsolete technology relics that the Frank Sharp Private museum has accumulated over the years .
Premise: There are lots of vintage electrical and electronic items that have not survived well or even completely disappeared and forgotten.

Or are not being collected nowadays in proportion to their significance or prevalence in their heyday, this is bad and the main part of the death land. The heavy, ugly sarcophagus; models with few endearing qualities, devices that have some over-riding disadvantage to ownership such as heavy weight,toxicity or inflated value when dismantled, tend to be under-represented by all but the most comprehensive collections and museums. They get relegated to the bottom of the wants list, derided as 'more trouble than they are worth', or just forgotten entirely. As a result, I started to notice gaps in the current representation of the history of electronic and electrical technology to the interested member of the public.

Following this idea around a bit, convinced me that a collection of the peculiar alone could not hope to survive on its own merits, but a museum that gave equal display space to the popular and the unpopular, would bring things to the attention of the average person that he has previously passed by or been shielded from. It's a matter of culture. From this, the Obsolete Technology Tellye Web Museum concept developed and all my other things too. It's an open platform for all electrical Electronic TV technology to have its few, but NOT last, moments of fame in a working, hand-on environment. We'll never own Colossus or Faraday's first transformer, but I can show things that you can't see at the Science Museum, and let you play with things that the Smithsonian can't allow people to touch, because my remit is different.

There was a society once that was the polar opposite of our disposable, junk society. A whole nation was built on the idea of placing quality before quantity in all things. The goal was not “more and newer,” but “better and higher" .This attitude was reflected not only in the manufacturing of material goods, but also in the realms of art and architecture, as well as in the social fabric of everyday life. The goal was for each new cohort of children to stand on a higher level than the preceding cohort: they were to be healthier, stronger, more intelligent, and more vibrant in every way.

The society that prioritized human, social and material quality is a Winner. Truly, it is the high point of all Western civilization. Consequently, its defeat meant the defeat of civilization itself.

Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

OLD, but ORIGINAL, Well made, Funny, Not remotely controlled............. and not Made in CHINA.

How to use the site:
- If you landed here via any Search Engine, you will get what you searched for and you can search more using the search this blog feature provided by Google. You can visit more posts scrolling the left blog archive of all posts of the month/year,
or you can click on the main photo-page to start from the main page. Doing so it starts from the most recent post to the older post simple clicking on the Older Post button on the bottom of each page after reading , post after post.

You can even visit all posts, time to time, when reaching the bottom end of each page and click on the Older Post button.

- If you arrived here at the main page via bookmark you can visit all the site scrolling the left blog archive of all posts of the month/year pointing were you want , or more simple You can even visit all blog posts, from newer to older, clicking at the end of each bottom page on the Older Post button.
So you can see all the blog/site content surfing all pages in it.

- The search this blog feature provided by Google is a real search engine. If you're pointing particular things it will search IT for you; or you can place a brand name in the search query at your choice and visit all results page by page. It's useful since the content of the site is very large.

Note that if you don't find what you searched for, try it after a period of time; the site is a never ending job !

Every CRT Television saved let revive knowledge, thoughts, moments of the past life which will never return again.........

Many contemporary "televisions" (more correctly named as displays) would not have this level of staying power, many would ware out or require major services within just five years or less and of course, there is that perennial bug bear of planned obsolescence where components are deliberately designed to fail and, or manufactured with limited edition specificities..... and without considering........picture......sound........quality........
..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

Have big FUN ! !
-----------------------
©2010, 2011, 2012, 2013, 2014 Frank Sharp - You do not have permission to copy photos and words from this blog, and any content may be never used it for auctions or commercial purposes, however feel free to post anything you see here with a courtesy link back, btw a link to the original post here , is mandatory.
All sets and apparates appearing here are property of Engineer Frank Sharp. NOTHING HERE IS FOR SALE !
All posts are presented here for informative, historical and educative purposes as applicable within Fair Use.


Wednesday, December 1, 2010

GRUNDIG SUPER COLOR P37-222 GCE15 CHASSIS CUC 2201 Video Unit (RGB Baustein 29504-105.02) View.





Luminance + Chrominance + Matrix + RGB Control With TDA3566 (PHILIPS)

TDA3566A

PAL/NTSC decoder




FEATURES




· A black-current stabilizer which

controls the black-currents of the

three electron-guns to a level low

enough to omit the black-level

adjustment




· Contrast control of inserted RGB

signals

· No black-level disturbance when

non-synchronized external RGB

signals are available on the inputs

· NTSC capability with hue control.



FEATURES
· A black-current stabilizer which
controls the black-currents of the
three electron-guns to a level low
enough to omit the black-level
adjustment
· Contrast control of inserted RGB
signals
· No black-level disturbance when
non-synchronized external RGB
signals are available on the inputs
· NTSC capability with hue control.
APPLICATIONS
· Teletext/broadcast antiope
· Channel number display.


GENERAL DESCRIPTION
The TDA3566A is a decoder for the
PAL and/or NTSC colour television
standards. It combines all functions
required for the identification and
demodulation of PAL/NTSC signals.
Furthermore it contains a luminance
amplifier, an RGB-matrix and
amplifier. These amplifiers supply
output signals up to 4 V peak-to-peak
(picture information) enabling direct
drive of the discrete output stages.
The circuit also contains separate
inputs for data insertion, analog and
digital, which can be used for text
display systems.

FUNCTIONAL DESCRIPTION
The TDA3566A is a further
development of the TDA3562A. It has
the same pinning and nearly the
same application. The differences
between the TDA3562A and the
TDA3566A are as follows:
· The NTSC-application has largely
been simplified. In the event of
NTSC the chrominance signal is
now internally coupled to the
demodulators, automatic
chrominance control (ACC) and
phase detectors. The chrominance
output signal (pin 28) is thus
suppressed. It follows that the
external switches and filters which
are required for the TDA3562A are
not required for the TDA3566A.
There is no difference between the
amplitudes of the colour output
signals in the PAL or NTSC mode.
· The clamp capacitor at pins 10, 20
and 21 in the black-level
stabilization loop can be reduced to
100 nF provided the stability of the
loop is maintained. Loop stability
depends on complete application.
The clamp capacitors receive a
pre-bias voltage to avoid coloured
background during switch-on.
· The crystal oscillator circuit has
been changed to prevent parasitic
oscillations on the third overtone of
the crystal. Consequently the
optimum tuning capacitance must
be reduced to 10 pF.
· The hue control has been improved
(linear).
Luminance amplifier
The luminance amplifier is voltage
driven and requires an input signal of
450 mV peak-to-peak (positive
video). The luminance delay line must
be connected between the IF
amplifier and the decoder.
The input signal is AC coupled to the
input (pin 8). After amplification, the
black level at the output of the
preamplifier is clamped to a fixed DC
level by the black level clamping
circuit. During three line periods after
vertical blanking, the luminance
signal is blanked out and the black
level reference voltage is inserted by
a switching circuit.
This black level reference voltage is
controlled via pin11 (brightness). At
the same time the RGB signals are
clamped. Noise and residual signals
have no influence during clamping
thus simple internal clamping circuitry
is used.
Chrominance amplifiers
The chrominance amplifier has an
asymmetrical input. The input signal
must be AC coupled (pin 4) and have
a minimum amplitude of
40 mV peak-to-peak.
The gain control stage has a control
range in excess of 30 dB, the
maximum input signal must not
exceed 1.1 V peak-to-peak,
otherwise clipping of the input signal
will occur.
From the gain control stage the
chrominance signal is fed to the
saturation control stage. Saturation is
linearly controlled via pin 5. The
control voltage range is 2 to 4 V, the
input impedance is high and the
saturation control range is in excess
of 50 dB.
The burst signal is not affected by
saturation control. The signal is then
fed to a gated amplifier which has a
12 dB higher gain during the
chrominance signal. As a result the
signal at the output (pin 28) has a
burst-to-chrominance ratio which is
6 dB lower than that of the input
signal when the saturation control is
set at -6 dB.
The chrominance output signal is fed
to the delay line and, after matrixing,
is applied to the demodulator input
pins (pins 22 and 23). These signals
are fed to the burst phase detector. In
the event of NTSC the chrominance
signal is internally coupled to the
demodulators, ACC and phase
detectors.
Oscillator and identification circuit
The burst phase detector is gated
with the narrow part of the sandcastle
pulse (pin 7). In the detector the
(R-Y) and (B-Y) signals are added to
provide the composite burst signal
again.
This composite signal is compared
with the oscillator signal
divided-by-2 (R-Y) reference signal.
The control voltage is available at
pins 24 and 25, and is also applied to
the 8.8 MHz oscillator. The 4.4 MHz
signal is obtained via the divide-by-2
circuit, which generates both the
(B-Y) and (R-Y) reference signals
and provides a 90° phase shift
between them.
The flip-flop is driven by pulses
obtained from the sandcastle
detector. For the identification of the
phase at PAL mode, the (R-Y)
reference signal coming from the PAL
switch, is compared to the vertical
signal (R-Y) of the PAL delay line.
This is carried out in the H/2 detector,
which is gated during burst.
When the phase is incorrect, the
flip-flop gets a reset from the
identification circuit. When the phase
is correct, the output voltage of the
H/2 detector is directly related to the
burst amplitude so that this voltage
can be used for the ACC.
To avoid 'blooming-up' of the picture
under weak input signal conditions
the ACC voltage is generated by peak
detection of the H/2 detector output
signal. The killer and identification
circuits receive their information from
a gated output signal of H/2 detector.
Killing is obtained via the saturation
control stage and the demodulators.

The time constant of the saturation
control (pin 5) provides a delayed
switch-on after killing. Adjustment of
the oscillator is achieved by variation
of the burst phase detector load
resistance between pins 24 and 25
(see Fig.8).
With this application the trimmer
capacitor in series with the 8.8 MHz
crystal (pin 26) can be replaced by a
fixed value capacitor to compensate
for unbalance of the phase detector.
Demodulator
The (R-Y) and (B-Y) demodulators
are driven by the colour difference
signals from the delay-line matrix
circuit and the reference signals from
the 8.8 MHz divider circuit. The (R-Y)
reference signal is fed via the
PAL-switch. The output signals are
fed to the R and B matrix circuits and
to the (G-Y) matrix to provide the
(G-Y) signal which is applied to the
G-matrix. The demodulation circuits
are killed and blanked by by-passing
the input signals.
NTSC mode
The NTSC mode is switched on when
the voltage at the burst phase
detector outputs (pins 24 and 25) is
adjusted below 9 V.
To ensure reliable application the
phase detector load resistors are
external. When the TDA3566A is
used only for PAL these two 33 kW
resistors must be connected to +12 V
(see Fig.8).
For PAL/NTSC application the value
of each resistor must be reduced to
20 kW (with a tolerance of 1%) and
connected to the slider of a
potentiometer (see Fig.9). The
switching transistor brings the voltage
at pins 24 and 25 below 9 V which
switches the circuit tot the NTSC
mode.
The position of the PAL flip-flop
ensures that the correct phase of the
(R-Y) reference signal is supplied to
the (R-Y) demodulator.
The drive to the H/2 detector is now
provided by the (B-Y) reference
signal. In the PAL mode it is driven by
the (R-Y) reference signal. Hue
control is realized by changing the
phase of the reference drive to the
burst phase detector.
This is achieved by varying the
voltage at pins 24 and 25 between
7.0 V and 8.5 V, nominal position
7.65 V. The hue control characteristic
is shown in Fig.6.
RGB matrix and amplifiers
The three matrix and amplifier circuits
are identical and only one circuit will
be described.
The luminance and the colour
difference signals are added in the
matrix circuit to obtain the colour
signal, which is then fed to the
contrast control stage.
The contrast control voltage is
supplied to pin 6 (high-input
impedance). The control range is
+5 dB to -11.5 dB nominal. The
relationship between the control
voltage and the gain is linear (see
Fig.3).
During the 3-line period after blanking
a pulse is inserted at the output of the
contrast control stage. The amplitude
of this pulse is varied by a control
voltage at pin 11. This applies a
variable offset to the normal black
level, thus providing brightness
control.
The brightness control range is 1 V to
3.6 V. While this offset level is
present, the black-current input
impedance (pin 18) is high and the
internal clamp circuit is activated. The
clamp circuit then compares the
reference voltage at pin 19 with the
voltage developed across the
external resistor network RA and
RB (pin 18) which is provided by
picture tube beam current.
The output of the comparator is
stored in capacitors connected from
pins 10, 20 and 21 to ground which
controls the black level at the output.
The reference voltage is composed
by the resistor divider network and the
leakage current of the picture tube
into this bleeder. During vertical
blanking, this voltage is stored in the
capacitor connected to pin 19, which
ensures that the leakage current of
the CRT does not influence the black
current measurement.
The RGB output signals can never
exceed a level of 10.6 V. When the
signal tends to exceed this level the
output signal is clipped. The black
level at the outputs (pins 13, 15 and
17) will be approximately 3 V. This
level depends on the spread of the
guns of the picture tube. If a beam
current stabilizer is not used it is
possible to stabilize the black levels at
the outputs, which in this application
must be connected to the black
current measuring input (pin 18) via a
resistor network.

Data insertion
Each colour amplifier has a separate
input for data insertion.
A 1 V peak-to-peak input signal
provides a 3.8 V peak-to-peak output
signal.
To avoid the black-level of the
inserted signal differing from the black
level of the normal video signal, the
data is clamped to the black level of
the luminance signal. Therefore AC
coupling is required for the data
inputs.
To avoid a disturbance of the blanking
level due to the clamping circuit, the
source impedance of the driver circuit
must not exceed 150 W. The data
insertion circuit is activated by the
data blanking input (pin 9). When the
voltage at this pin exceeds a level of
0.9 V, the RGB matrix circuits are
switched off and the data amplifiers
are switched on.
To avoid coloured edges, the data
blanking switching time is short. The
amplitude of the data output signals is
controlled by the contrast control at
pin 6. The black level is equal to the
video black level and can be varied
between 2 and 4 V (nominal
condition) by the brightness control
voltage at pin 11.
Non-synchronized data signals do not
disturb the black level of the internal
signals.
Blanking of RGB and data signals
Both the RGB and data signals can
be blanked via the sandcastle input
(pin 7). A slicing level of 1.5 V is used
for this blanking function, so that the
wide part of the sandcastle pulse is
separated from the remainder of the
pulse. During blanking a level of +1 V
is available at the output. To prevent
parasitic oscillations on the third
overtone of the crystal the optimum
tuning capacitance should be 10 pF.

Notes to the characteristics
1. Signal with the negative-going sync; amplitude includes sync pulse amplitude.
2. Indicated is a signal with 75% colour bar, so the chrominance-to-burst ratio is 2.2 : 1.
3. Nominal contrast is specified as the maximum contrast -5 dB and nominal saturation as maximum -6 dB. This figure
is valid in the PAL-condition. In the NTSC-condition no output signal is available at pin 28.
4. Cross coupling is measured under the following condition: input signal nominal, contrast and saturation such that
nominal output signals are obtained. The signals at the output at which no signal should be available must be
compared with the nominal output signal at that output.
5. The signal-to-noise ratio is defined as peak-to-peak signal with respect to RMS noise.
6. All frequency variations are referenced to the 4.4 MHz carrier frequency. All oscillator specifications have been
measured with the Philips crystal 4322 143 ... or 4322 144 ... series.
7. The change in burst with VP is proportional.
8. These signal amplitudes are determined by the ACC circuit of the reference part.
9. This value depends on the gain setting of the RGB output amplifiers and the drift of the picture tube guns. Higher
black level values are possible (up to 5 V) however, in that condition the amplitude of the available output signal is
reduced.
10. The variation of the black-level during brightness control in the three different channels is directly dependent on the
gain of each channel. Discolouration during adjustments of contrast and brightness does not occur because
amplitude and the black-level change with brightness control are directly related.
11. With respect to the measuring pulse.
12. This difference occurs when the source impedance of the data signals is 150 W and the black level clamp pulse width
is 4 ms (sandcastle pulse). For a lower impedance the difference will be lower.
13. For correct operating of the black level stabilization loop, the leading and trailing edges of the sandcastle pulse
(measured between 1.5 V and 3.5 V) must be within 200 ns and 600 ns respectively.
14. The voltage at pins 24 and 25 can be changed by connecting the load resistors (20 kW, 1%, in this condition) to the
slider bar of the hue control potentiometer (see Fig.6). When the transistor is switched on, the voltage at pins 24 and
25 is reduced below 9 V, and the circuit is switched to NTSC mode. The width of the burst gate is assumed to be
4 ms typical.


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