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.

Saturday, September 10, 2011

PHILIPS I12T720/02 " POSITANO " CHASSIS 8219.273.3011.5 CRT TUBE PHILIPS A31-120W



31cm (12in) rectangular direct viewing television tube with metal backed screen
and reinforced envelope. A separate safety screen is not required. Especially
for use in portable receivers with push—through presentation.

Deflection angle 110 deg
Focusing Electrostatic

Light transmission 50 %
Maximum overall length 233 mm

This data should be read in conjunction with

Vh 11 V
Ih 75 mA

The maximum total deviation from the nominal heater voltage is 15%.

The deviation consists of 7% maximum continuous deviation, for example, due to
component spread and 10% maximum temporary deviation.

For supply direct from a battery, the heater voltage cycle must be within the limits
of the graph on page 10 .


Va2 ’ 34 11 kV
VA3 (focus electrode) control range 0 to 350 V
Va1 250 V
Vg for visual extinction of focused raster -35 to -69 V
*Vk for visual extinction of focused raster 32 to 58 V

*For cathode modulation, all voltages are measured with respect to grid.

Metal backed
Fluorescent colour White
Light transmission (approx.) 50 %

FOCUSING Electrostatic


Diagonal deflection angle 110 deg
Horizontal deflection angle 99 deg
Vertical deflection angle 80 deg

The deflection coils should be designed so that their internal contour is in accordance
with the reference line gauge shown on page 4 .

cg_aLL 7 0 pF
ck_all 3 0 pF
ca2’a4_M 450 to 900 pF
ca2’a4_B 300 pF


This tube has an external conductive coating, M, which must be connected to chassis,
and the capacitance of this coating to the final anode is used to provide smoothing
for the e.h.t. supply. The electrical connection to this coating must be made within
the area specified on the tube outline drawing.


See notes under this heading in ‘General Operational Recommendations — Television
Picture Tubes‘.

Centring magnet field intensity 0 to 800 A/ m
Maximum distance of centre of
centring field from reference line 4'? mm

Adjustment of the centring magnet should not be such that a general reduction in
brightness of the raster occurs.


The tube socket should not be rigidly mounted but should have flexible leads and be
allowed to move freely.

This tube is fitted with a pin protector in order to avoid damage to the glass base
due to bending of the base pins whilst handling the tube.

It is advisable to keep this pin protector on the base until it can be replaced by the
socket after the installation of the tube in any equipment .


RATINGS (DESIGN CENTRE SYSTEM unless otherwise stated)

Va2’a4 max. (at Ia2’a4=0) (see note 1) 12 kV
Va2’a4 min. (absolute limit) 8.5 kV
+V max. 500 V
-V max. 50 V
V max 350 V
V min. 200 V
-vgxpk) max. (see note 2) 350 V
-Vg max. (see note 3) 100 V
+-Ia3 max. 25 uA
+-Ia1 max. 5.0 pm
vh-k (cathode positive)
d.c. max. 110 V
pk max. 130 V
Rh_k max. 1 .0 M52
Zk_e max. (f =50Hz) 100 kOHM
R max. 1.5 MOHM
Zg_k max. (f =50Hz) 500 kOHM
RM_B min. 2 .0 MOHM

1. Adequate precautions should be taken to ensure that the receiver is protected
from damage which may be caused by a possible high voltage flashover within
the tube .

Maximum pulse duration 22% of one cycle with a maximum of 1.5ms.

The d.c . value of bias must not be such as to allow the grid to become positive
with respect to the cathode, except during the period immediately after switching
the receiver on or off when it may be allowed to rise to +2. 0V. It is advisable to
limit the positive excursion of the video signal to +5V(pk) max. This may be
achieved automatically by the series connection of a 10kQ resistor.

The metal band must be earthed by means of the tag provided.

The mounting lugs will not necessarily be in electrical contact with the metal

Tube alone (approx .) 2 . 8 kg

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.

Note: Only a member of this blog may post a comment.