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Forum 141

Telefunken 614 - 14" Portable 511 Chassis

Colour Television

Last Post by PaulGoggo1 8 years ago

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PaulGoggo1

(@paulgoggo1)

Posts: 89

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Topic starter

Hello

Following my earlier post in the wanted section regarding Telefunken TVs , I managed to obtain a 14" portable 614 from Ebay Germany.
This has the 511 chassis, very similar to the bigger brother 711/711A. its a very heavy set though for its size!

It was not a functioning set so it was a risk, but it arrived safely with no damage. Condition very good considering the age of the set. It was dead of course, so still not knowing what condition the CRT would be in the back was cautiously removed. I have the full official Service Manual for the set and had lots of experience with the larger (110 degree 711 Chassis) I could be in with a chance!
The chassis was remarkably clean so looked like it had little use. First checks revealed the Main Fuse (4A) was O/C, also blackened, so a hefty S/C somewhere.
looking at the (Small) PSU pcb revealed 2 burnt out tracks on the primary side. No Shorts could be found so the tracks were made good and a 3.15A fuse fitted. (No Variac anymore!) Big Flash! from PCB, Fuse held!
More Tracks fried!..Close checks found the degauss positor has chipped and had flashed over to a very close proximity heatsink. Repaired tracks (again!)and replaced the bad positor with a suitable nice positor and at arms length, switched on.. Hiss from sound and rustle up of EHT. So far so good. After about a minute or so a snow filled raster appeared and looked ok.
I didnt leave the set on for long as its rated at 220v not 240v and I feared for the CRT voltage which when measured was 7.5v ac. Its derived from a winding on the mains TX. The PSU can cope with the higher voltage though.
A suitable low value resistor was fitted in line with the heater supply (on CRT base) and this brought it down to a healthy 6.32v.
The set is German TV standard of course so the trusty Promax Pattern generator was brought into use with suitable settings and a PM5544 pattern selected. After some tweaks to the Power supplies for correct voltages and some slight reconvergence the picture looked good with lots of brightness on contrast. Clearly the CRT was fine! Some slight adjustments to the sound trap to remove some slight patterning and a slight adjustment of the delay line coils, it looked good for a 42 year old set! However after about 10mins a very large Hum bar/ ripple appeared and was distorting the raster.
The PSU volts looked about right so out with the Scope! Massive ripple on main HT (175v line). This was due to the 2N3055 regulator going slightly leaky when warm (very warm!). Having sorted this diversion it was finally ok! I have left it to the German Standard for now, maybe try system I later!
Heres an off screen picture of the PM5544 after the tweaks. Very similar to its bigger brothers which I'm still looking for so please look in the parts required section (Telefunken TV 1970s) if you can help. Thanks Paul G

Posted : 04/12/2015 5:19 pm

crustytv

(@crustytv)

Posts: 11869

Vrat Founder Admin

Hi Paul,

That test card looks absolutely spot on!

Well done on a) finding the set and b) a good repair and log of the process to get it back to working order. I would be interested to see a picture of the actual set and I've not seen one before. What CRT was used in this set ( manufacturer)

Keep up the good work and fingers crossed you find your ultimate goal set.

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Posted : 04/12/2015 9:05 pm

PaulGoggo1

(@paulgoggo1)

Posts: 89

Estimable Member Registered

Topic starter

crustytv said
Hi Paul,

That test card looks absolutely spot on!

Well done on a) finding the set and b) a good repair and log of the process to get it back to working order. I would be interested to see a picture of the actual set and I've not seen one before. What CRT was used in this set ( manufacturer)

Keep up the good work and fingers crossed you find your ultimate goal set.

Hi Crusty Tv

Yes it was a lucky find. I see another one has appeared on Ebay Germany! I will post some pics of the actual set shortly. The CRT was a 370BCB 22 (its a 90 degree crt) pretty rare. Looks like a Toshiba type will have to peel the upper label off to find out.

Paul

Posted : 06/12/2015 4:27 pm