[phpBB Debug] PHP Warning: in file /includes/functions.php on line 4559: Invalid argument supplied for foreach()
Dampfradioforum • Thema anzeigen - Philips leonardo 21td310a

Dampfradioforum

Röhrenradioforum: Das Forum für alle Freunde alter Röhrenradios, Kofferradios und Röhrentechnik!
Aktuelle Zeit: Mi Aug 15, 2018 6:41

Alle Zeiten sind UTC + 1 Stunde [ Sommerzeit ]




Ein neues Thema erstellen Auf das Thema antworten  [ 11 Beiträge ] 
Autor Nachricht
 Betreff des Beitrags: Philips leonardo 21td310a
BeitragVerfasst: So Aug 05, 2018 22:45 
Offline

Registriert: So Aug 05, 2018 22:41
Beiträge: 15
Kenntnisstand: Sehr gute Kenntnisse (Hobby)
hi
i am 30years old and i am from Portugal
i recently got into the hobby of restoring tube televisions and radios
sorry for posting in English but i cannot speak or write German
if you are bothered with this please let me know and i will not post anymore


I just finished (i hope) repairing this philips tv
it has a rebuilt crt by GE Portugal and it was rebuilt in 1980
it came almost untouched when it comes to components
it is fully packed with mullard mustard capacitors wich all test good even after all these years
the carbon resistors are amazingly within spec
it came with a melted capacitor inside the high voltage cage and i replaced the mains filters for good measure. it came with 2 cans each containing 4 capacitors!!!!
it now displays a nice watchable picture and it seems stable to watch a movie without issues
this set has 8 diodes and 22 valves..fairly complicated like most german stuff
it has automatic image stabilization so no hold controls acessible from the outside.it also seems to regulate brightness and contrast to compensate for line voltage fluctuations

Dateianhang:
WP_20180729_19_22_20_Pro.jpg
WP_20180729_19_22_20_Pro.jpg [ 161.25 KiB | 522-mal betrachtet ]


only issue so far is the flyback seems to get a bit warm to the touch and after some hours of use i found a drip of wax on the chassis
the ambient temperature on that day was very high with almost 40ºC inside the house though
there seems to be no arcing and no funny smells, i watched a few episodes of miami vice with a dvd player and was very pleasant to watch

Dateianhang:
Sem Título.png
Sem Título.png [ 173.83 KiB | 521-mal betrachtet ]


this is the audio ouput stage and i posted here the schematic because it is so wierd that i dont fully understand it yet
i was hoping someone could shed me some light on its workings
althougt it is working fine i am curious
the speaker is 800ohms impedance, it does not use an output transformer, the speaker magnet is tiny and its on the side of the speker basket (YES) and the cone is held in mid air only by the suspension foam (no spider, no magnet inside the voice coil), almost looks like a giant electrostatic tweeter
also b+ goes through the speaker to the grid of the output tube and audio comes out of the grid of the output tube instead of the usual that is feeding audio signal through the grid and audio exits anyway it actually sounds very good for a tv.


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Mo Aug 06, 2018 8:41 
Offline

Registriert: Di Apr 19, 2016 20:33
Beiträge: 372
Kenntnisstand: Elektrotechnischer Beruf/ Studium
Hello Nameless,

you got a fine TV set. It was made by German Philips in Krefeld in 1960.

The line output transformer is the most vulnerable part in the set. It is normal that it reaches a certain temperature. The core should be hardly touchable after an hour of operation, not much more. Maybe you shouldn't use it with this hot summer weather. Important: the booster voltage must be adjusted to the right value, better about 5 percent less. See diagram. The capacitor between anode of horiz oscillator and g1 of PL 500 must be in perfect condition, please use a good modern one!

The audio output stage was a Philips specialty of these days, also used in many Philips radios. It is a SRPP circuit (Shunt-regulated push-pull). It is used in some of today's tube amplifiers as preamp stages.
In this circuit, the output tubes are in parallel for ac (audio) and in line for dc (rail voltage).

the strange speaker was also a Philips specialty, only used in TV sets and portable record players with the speaker mounted in the cover (because of its small depth)

Btw. The mustard-colored caps are not from Mullard, but made by Philips-Valvo in Hamburg-Langenhorn, Germany. ;-)

Regards
Stefan


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Mo Aug 06, 2018 14:02 
Offline

Registriert: So Aug 05, 2018 22:41
Beiträge: 15
Kenntnisstand: Sehr gute Kenntnisse (Hobby)
Thank you for you input Stefan
i forgot to say , my name is Hugo

so you mentioned some important things
the core of the transformer i did not touch but the high voltage winding was only warm..maybe 50ºc / 55ºc not more...i just got a bit scared by the drip of wax

the capacitor you talked about i highlighted it i red on the schematic below, i have not changed it because it is ceramic...it is a 500v rated part . can i place a 630v tubular capacitor or does it have to be high pulse resistant?like the philips orange 1700v mkp series for example?

i have not checked the boost voltage, the schematic calls for 960v
when the set arrived it had a rolling picture both horizontal and vertically and i had to tweak the oscillator coil a bit for the picture to stabilize , i highlighted the coil in green on the schematic below
tweaking this coil affects the boost voltage i know that because it changes the horizontal oscillator frequency, anyway i just twaeked it a little bit maybe one turn and a half or something.
i will check the boost voltage tomorrow and report it to you
are there serious consequences if it is a bit off? the set sems to work reasonably well. i note some random contrast variations between scenes on movies but nothing too big deal, maybe some auto regulation feature, i have studied and understood most of the schematic but there are still some obscure parts and features on this tv., atleast for the less experienced...



Dateianhang:
Sem Título.png
Sem Título.png [ 175.69 KiB | 454-mal betrachtet ]


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Mo Aug 06, 2018 19:38 
Offline

Registriert: Di Apr 19, 2016 20:33
Beiträge: 372
Kenntnisstand: Elektrotechnischer Beruf/ Studium
Hello Hugo,

yes, a 630Volt type will do it. Set the booster voltage to about 930 volts, that's okay. The missing 30 v will not really decrease brightness and high tension, but helps the line output transformer to spare a few degrees to live a little longer.

Regards Stefan


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Mo Aug 06, 2018 21:30 
Offline

Registriert: So Aug 05, 2018 22:41
Beiträge: 15
Kenntnisstand: Sehr gute Kenntnisse (Hobby)
ok Stefan and everyone else :hello:

before we go to the boost voltage topic ,here is a pic of the inside of the tv and a more detailed description of the work made:
you see the blue ceramic caps? when i first plug in the set, some tubes flash or light up very fast and very hard and then they go to normal filament brightness so i thought i had leaky capacitors on the filaments series string to ground(very common) so as a precautionary measure i replaced all of the ceramic caps that go to ground (1,5 nf 500v) (did not touch the ones on tuned circuits etc, only decoupling caps to ground were precision is not critical) but then i found out that the old ones were good! it was a thing of my tubes, if i put different tubes they don't do that anymore :oops:

but anyway new 2kv ceramic caps instead of the 500v old ones cannot hurt.
also as you can see i replaced the small electrolytics because they were leaking fluids to the boards...for 8uf i used 10uf and there were some 0,32uf and 0,64uf wich i replaced with 0,47. they tested fine but had signs of fluid leakage.
the mustard caps that coupled signals from plate to grid of the next tube i removed them carefully and tested them for leakage...they were perfect and i put them back on with the exception of one wich was a bit leaky.
this work was done before my first post here on the forum

i dont have a leakage tester so when i want to test 400 or 500v capacitors for leakage i have a crude method: put my meter on dc volts, plug the capacitor to the 220v socket with a diode and the meter all in series, it should show 0v on the meter..if it reads any dc voltage than the capacitor is leaky.it actually works very well.

Dateianhang:
WP_20180806_20_01_18_Pro.jpg
WP_20180806_20_01_18_Pro.jpg [ 178.3 KiB | 408-mal betrachtet ]


Dateianhang:
WP_20180806_20_01_29_Pro.jpg
WP_20180806_20_01_29_Pro.jpg [ 174.87 KiB | 408-mal betrachtet ]



ok now regarding your advices:

i replaced the capacitor you mentioned with a 630v tubular new one
tv is working fine of course

my boosterspannung is at 1020 volts ...a touch on the high side but if i tweak the horizontal oscillator coil the voltage goes up or down depending on the direction i turn it but i loose image sync...what should i do?

thanks for your time
:bier:


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Mo Aug 06, 2018 22:07 
Offline

Registriert: Mi Okt 14, 2009 10:34
Beiträge: 720
Wohnort: 258xx Plattstedt
Kenntnisstand: Elektrotechnischer Beruf/ Studium
Moin!
Please adjust the Booster Voltage with R125.
It is marked 'BB', which means 'Bildbreite' or 'Picture With'.
Regards, Gerrit


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Di Aug 07, 2018 3:05 
Offline

Registriert: So Aug 05, 2018 22:41
Beiträge: 15
Kenntnisstand: Sehr gute Kenntnisse (Hobby)
i am glad i found this forum

on the american foruns people dont even want to comment on german Tv topics, thats just too complicated for them, american sets seem to have have half the components

anyway lets move on

i just tweaked r125 to get the boosterspannung to 930v but i had no full horizontal deflection, i could see 1 centimeter of black bar on each side of the screen
full horizontal deflection happens exactly at 960v like the schematic calls so i left it at 960v because i like to see the screen all filled and no black bars
this tells me that the PL36 horizontal output tube must be in good shape

so thank you A LOT for the good advice
i did not know that the width control affected the boost voltage so i learned something new
:super:


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Di Aug 07, 2018 6:44 
Offline

Registriert: Di Apr 19, 2016 20:33
Beiträge: 372
Kenntnisstand: Elektrotechnischer Beruf/ Studium
Hugo,

of course the screen should be fully written without bars. If these only applies with 960volts, adjust it to that voltage (normally, this is not that critcal). But 1020 is definitely too much. The booster capacitor is a new one? It should be.
Btw, with every change in the line output stage, such as replacing the PL 36, booster voltage has to be checked and adjusted the way yehti says. He also has large experience with the tv stuff.

Of course, first horizontal sync must be adjustd to a stable picture, then fine tune the booster voltage.

With the capacitors you did a fine work. Replacing the ceramic caps in heater circuit was, I assume, not neccessary, but it cannot hurt, as you say. Lighting up brightly for a short moment after switching on is in fact normal behaviour of SOME tubes and no reason to worry!
Didn't you have any trouble with the printed circuit when soldering on it? The copper leads tend to loosen from the board when heating up, this is due to bad quality of these early philips pcbs.

There is an additional source of future trouble in your Philips. If you surely learned, there are two different types of resistors used. There are the ones with shiny dark red laquer on it - theses are excellent - and some with a brown, dull, uneven surface with broad, uneven color rings. These are carbon composite resistors of bad quality (Vitrohm-Kohlemasse-Widerstände). They tend to increase their values with age significantly. Please check them, at least those with higher values, maybe from 47k upwards.

Did you check if there is a large capacitor of about 0,1µF hidden behind the mains switch? They can be found in some Philips sets. Replace it.

Much fun with your Leonardo wishes Stefan


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Di Aug 07, 2018 22:35 
Offline

Registriert: So Aug 05, 2018 22:41
Beiträge: 15
Kenntnisstand: Sehr gute Kenntnisse (Hobby)
Dateianhang:
WP_20180807_21_18_24_Pro.jpg
WP_20180807_21_18_24_Pro.jpg [ 170.2 KiB | 313-mal betrachtet ]


hi stefan
thanks for the tips

if i ever one day change the pl36 i will remind to verify that

about the board i did not have any trouble, i am used to that since i restored a Dynacord concert valve amplifier and the boards are even worse..and it had immense moisture damage..
the trick is not to pry sideways on the component you remove and when installing the new one the holes must be heated up or it will hit the solder residue and lift the trace off the board, or you can also use a good solder sucker but i didnt need to. when installing the new component i advise to leave it in contact with the board. if you leave it hanging high distant from the board then if you accidentally press down on the component, the copper trace will lift off the board...hope my english makes sense... i also found a lot of cold solder joints on the left board but all joints were good on the right board.. :shock:

yes i know those nasty carbon resistors especially the ones with high values they tend to get even higher...i checked a bunch of them (not all) and they were reasonably in tolerance suprisingly

the across the line capacitor (tar capacitor) was hidden like you said but i found it and replaced it with a X Y safety capacitor, those square ones, i think i put a 0,22uf but the value is not important there

the boost capacitor was melted into a soup of black tar and i put a 1700v mkp one. i zip tied it, glued it and put a piece of cardboard between it and the chassis (photo above)

guess its time to move to other projects and watch some movies! :super:

i also have a habit of buying the most cheap and broken radios with bakelite cabinets missing pieces and i like to repair the cabinets ( i worked on auto body shop) so if you guys think it would be interesting i can put some topics of those radios and the methods i use may be of interest to someone.
check out this nordmende tv before and after (unfortunately crt dead and Line output transformer open)
Dateianhang:
WP_20180412_19_33_25_Pro.jpg
WP_20180412_19_33_25_Pro.jpg [ 150.81 KiB | 313-mal betrachtet ]

Dateianhang:
WP_20180412_20_37_05_Pro.jpg
WP_20180412_20_37_05_Pro.jpg [ 174.46 KiB | 313-mal betrachtet ]

Dateianhang:
WP_20180418_13_02_11_Pro.jpg
WP_20180418_13_02_11_Pro.jpg [ 124.1 KiB | 313-mal betrachtet ]


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Mi Aug 08, 2018 11:04 
Offline

Registriert: Di Apr 19, 2016 20:33
Beiträge: 372
Kenntnisstand: Elektrotechnischer Beruf/ Studium
Well, that's a difference! Obviously you are a wood artist!
:D
Stefan


Nach oben
 Profil  
Mit Zitat antworten  
 Betreff des Beitrags: Re: Philips leonardo 21td310a
BeitragVerfasst: Do Aug 09, 2018 20:38 
Offline

Registriert: So Aug 05, 2018 22:41
Beiträge: 15
Kenntnisstand: Sehr gute Kenntnisse (Hobby)
thank you but i am not very good with wood, i just had a lot of patience

i used mostly automotive products to restore that tv cabinet (filler, paint , etc)

i put a topic on the valve radio cabinet restoration section on this forum showing what i normally use, check it out

:super:


Danke, aber ich bin nicht sehr gut mit Holz, ich hatte nur eine Menge Geduld

Ich verwendete hauptsächlich Automobilprodukte, um diesen Fernsehschrank (Füller, Farbe, usw.) wieder herzustellen

Ich habe ein Thema auf dem Ventil Radio Schrank Wiederherstellung Abschnitt in diesem Forum, was zeigt, was ich normalerweise verwende, überprüfen Sie es aus


viewtopic.php?f=33&t=28314


Nach oben
 Profil  
Mit Zitat antworten  
Beiträge der letzten Zeit anzeigen:  Sortiere nach  
Ein neues Thema erstellen Auf das Thema antworten  [ 11 Beiträge ] 

Alle Zeiten sind UTC + 1 Stunde [ Sommerzeit ]


Wer ist online?

Mitglieder in diesem Forum: 0 Mitglieder und 2 Gäste


Sie dürfen keine neuen Themen in diesem Forum erstellen.
Sie dürfen keine Antworten zu Themen in diesem Forum erstellen.
Sie dürfen Ihre Beiträge in diesem Forum nicht ändern.
Sie dürfen Ihre Beiträge in diesem Forum nicht löschen.
Sie dürfen keine Dateianhänge in diesem Forum erstellen.

Suche nach:
Gehe zu:  
POWERED_BY
Deutsche Übersetzung durch phpBB.de

 
Impressum