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 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 !

Saturday, February 5, 2011

PHILIPS 26CS3274 /01R "Durer" CHASSIS K35 (d) INTERNAL VIEW


















































The PHILIPS CHASSIS K35 it's a higly reliable monocarrier chassis and it's fully modular so it's service friendly.

It seems simple but, as any serious chassis, it's not, and it's even quite sophisticated.

Anyway these gave small problems and they were easy to service.
The Philips KT3 and K30 K35 chassis have been used in Pye and Philips colour sets from 1979-1980  to 1983. They are of modular construction, consisting of seven plug-in daughter boards units mounted on a main mother panel. The KT3 is designed to drive Philips 90° in -line gun tubes with screen sizes up to 20in. Its big screen sister, the K30, drives 110° 30AX tubes in 22 and 26in. screen sizes. Apart from this the two chassis are electrically very similar, the main differences being associated with the line output stage: the KT3 uses a line output transformer plus tripler powered from a 129V h.t. rail, whilst the K30 has a diode -split line output transformer and 140V h.t. rail. The modules are for the most part directly interchangeable, the exceptions being the chopper control and sound panels. There have been two versions of each chassis. The 1982 versions are known as "edition II". They incorporate slight changes in the mother panel and a completely redesigned decoder panel which is not interchangeable with the earlier panel. The new decoder panel has a single PHILIPS TDA3560 chip whilst the earlier panel uses a TDA2560Q and a TDA2523Q. In addition an improved power supply (chopper control) panel, type BY02, has been introduced. It's a direct replacement for the previous panels. To service a panel "in situ", a module extension board is required (part number 39537085). The KT3 and K30 chassis have proved to be extremely reliable, so there's only a limited fault history. Our experiences to date are summarised below.

Random Tripping;
Because of the high sensitivity of the power supply, look for dry joints etc. rather than a faulty component. Usual causes are as follows. Incorrect h.t. setting - the h.t. can be conveniently measured at pins 2 or 4 of the line scan coils connector M5. The e.h.t. lead not being pushed home fully into the line output transformer (K30 chassis only). Dirt or grease (e.g. cigarette tarnish) around the e.h.t. cap, focus unit or the printed c.r.t. spark gaps - clean with a suitable solvent, e.g. alcool. If necessary, carry out the following modifications: change R7354 from 27042 to 56052 (at the same time, if there's a resistor in parallel with R1461, remove it); fit (if not there already) an 0.1μF capacitor (C7337) between pin 12 of IC7322 (TDA2581Q) and the base of T7336 (BC558).

Tripping:
If the set trips three minutes after switching on, check the efficiency diode (D1464) in the chopper circuit. It should be type BY208 in the KT3 chassis and type BYX55-600 in the K30. If it's running warm or of incorrect type, replace it. If there's permanent tripping (ticking), disconnect the line scan connector M5 to isolate the line output stage. If the tripping stops and the h.t. is correct, check the tripler (KT3), the line output transistor T1562 (BU205 KT3, BU208A K30), and the EW modulator diodes D1562 and D1567. D1567 is type BY228 in both chassis; D1562 is type BY208 in the KT3, type BYX55-600 in the K30. If necessary check the line output transformer. If the tripping persists with M5 disconnected, i.e. the h.t. voltage is varying, the fault is in the power supply Check the chopper transistor T1463 (BUW84 KT3, BU426V K30), the efficiency diode D1464 (see above) and the chopper control panel by substitution.

Dead Set:
If the fuses have blown, replace the BY227 bridge rectifier diodes D6292/4/5/6 and of course the fuses - 2A delay types. If some 300V is present across the bridge rectifier's reservoir capacitor C1460a (part of the electrolytic can C1460a/b/c), check the h.t. at C1460c. If the reading is 300V, the chopper transistor T1463 is short-circuit. If the reading is zero, either the chopper transistor is duff or it's not being switched on. In the latter event, check first whether the 12V output from the rectifier panel is present at point 10 on this panel - or is less than 9V. If this supply is correct and is reaching point 12 on the chopper control panel, the latter is faulty. The usual offenders on the chopper control panel are the 6.8V zener diode D7343 (type BZX79-B6V8 - check for 6.8V at pin 10 of the i.c.) and the TDA2581Q chip itself (IC7322). If necessary carry out cold resistance component checks. The TDA2581Q chip provides protection under the following conditions: voltage at pin 7 higher than 6.8V (over -voltage protection); the pulse amplitude at pin 6 exceeds -0.6V (excess -current protection); voltage at pin 9 less than 9V (low i.c. supply); voltage at pin 10 exceeds 8.2V (excessive reference voltage, i.e. the zener diode D7343 is open -circuit); the voltage at pin 5 is 5V (this is the stand-by facility).

No Raster:
Check whether the orange plug has dropped off the focus unit (K30 only). In both the KT3 and the K30 chassis, the c.r.t.'s first anode supply/supplies are derived from the earthy side of the 24Mi2 focus potentiometer. Check whether the surge limiter R1590 in the 30/32V supply is open -circuit. This line output transformer derived supply is used by the field driver and output stages. It also biases off the field flyback blanking transistor T1535 (BC558) during the field scan, so its absence leaves this transistor hard on and no raster. Field Collapse If the 30/32V supply is missing (30V in the KT3 chassis, 32V in the K30), it's usually necessary to replace the surge limiter resistor R1590 (3.352 KT3, 1.2(1 K30), the two transistors in the field output stage, and their emitter resistors R1531/2. The resistors are 0.5W safety types, value 1.5n. The transistors are BD223/BD234 (T1530/T1532) in the KT3, BD437/BD438 (T1530/T1532) in the K30. Also check the field scan coupling capacitor C1521 (470μF KT3, 1500μF K30). Other causes of field collapse (30/32V supply o.k.) are cracks in the print around the edge of the mother board near the field driver and output stages or a faulty field oscillator (this is on the sync panel).

Field Linearity:
If poor, check by replacement the following feedback capacitors: C1522 (220μF) and C1541 (0.056μF). Check whether the feedback resistor R1502 is open -circuit (1551, 0.25W safety type).

Sync Faults:
In  the event of a rolling picture, replace all four transistors on the sync panel - T8386 (BC548), T8392 (BC548B), T8397 (BC558) and T8396 (BC548C). Only when the line sync is also poor is the TDA2571AQ sync i.c. suspect. Teletext Sets On teletext (Mk. II) KT3 and K30 K35 sets the teletext power panel at the base of the cabinet seems to be vulnerable to transit damage - you can get badly cracked panels. Failure of the 5V regulator IC1007 (MC7805CT) that supplies the teletext decoder panel results in complete loss of sync.

No Sound:
Make sure the customer hasn't switched off the loudspeaker - a muting switch is fitted on the front in most sets. Next check whether the supply is present at point 12 on the sound module. This is 20V in the KT3, 28V in the K30, and comes from a chopper transformer fed rectifier on the bridge rectifier panel. If the supply is absent, check R1413 (4 .71/ KT3, 8.252K30) and if necessary R6303 (2.2(1) on the bridge rectifier panel. Failure of these resistors is almost always due to a duff TDA2611AQ audio output i.c. (IC5181). If the supply is present, apply a signal (your finger on a screwdriver blade will do) at pin 7 of IC5181. If a hum is heard, the audio i.c. is o.k. and the most likely culprit is the TBA120AS intercarrier sound i.c. (IC5164).

Tone sound Sibilance:
Some customers complain that their sets suffer from excessive treble/sibilance, particularly those fitted with the KT3 chassis. This is not a fault in itself, but an improvement can be obtained by increasing the value of the de emphasis capacitor C5177 to 0.039μF as in production.

The Cabinet:
I've always found it best and safest to glue the front surround to the cabinet and use a sufficient quantity of self -tapping or wood screws of suitable length.

White Raster:
If there's a flooded white raster with the brightness and contrast controls having no effect, you will probably find that the 155V line filter resistor 81456 (1000 safety) is open -circuit due to a short-circuit transistor in one of the RGB output stages. Use cold resistance checks on the RGB panel as the voltage readings obtained are often confusing, then replace as necessary. In the edition II version of the KT3 R1456 becomes R1587. never more than a quarter of a turn.

No problems have been experienced with the i.f. module to date except for over aged capacitors which barely fail.

Poor HF Resolution:
If the picture is not as sharp as it could be, a fractional adjustment of the tuner's i.f. output coil is required

Tuner:
The U321 tuner unit should be replaced if the fault is low gain, cross modulation, etc.

No comments:

Post a Comment

The most important thing to remember about the Comment Rules is this:
The determination of whether any comment is in compliance is at the sole discretion of this blog’s owner.

Comments on this blog may be blocked or deleted at any time.
Fair people are getting fair reply. Spam and useless crap and filthy comments / scrapers / observations goes all directly to My Private HELL without even appearing in public !!!

The fact that a comment is permitted in no way constitutes an endorsement of any view expressed, fact alleged, or link provided in that comment by the administrator of this site.
This means that there may be a delay between the submission and the eventual appearance of your comment.

Requiring blog comments to obey well-defined rules does not infringe on the free speech of commenters.

Resisting the tide of post-modernity may be difficult, but I will attempt it anyway.

Your choice.........Live or DIE.
That indeed is where your liberty lies.