Sunday, 11 January 2015

Sony KV1320 UB MKI restoration.

This has to be the shortest restoration ever. I normally like a bit of a fight from my restorations! A few juicy faults, but not this one! Testament to the quality of late 60's Japanese Engineering.

Now back in the day, set manufacturers had to pay a license fee to Telefunken to use the PAL system, rumoured to be about £30 a set. Sony got around this by decoding the colour signal in a manner which didn't infringe Telefunken's patents. Sony used a modified NTSC decoder, which had an additional delay line, and the colour was repeated from the previously decoded line, reducing the colour resolution, but on such a small screen this isn't noticeable. Any problems with phase could be corrected with the provided hue control, which PAL receivers didn't have, nor need.

Most of these sets died due to being worn out. It is very rare to find one with a decent CRT in, so I wasn't hoping for much, and anyways I paid little money for it, and it's a KV-1320 MKI, a very early one, as several revisions were made.

Being an early model, it has a 3AT2 EHT rectifier valve, and has the CRT heaters permanently connected and warm (not good for CRT longevity!) , regardless of the mains switch position.

This one arrived dead. No tube heaters, nothing.

Opening the mains plug... and the fuse is open circuit!

Replacing that and great pictures!!

 A quick tweak to the frame height and centering

Sit down, and watch telly! A sticker on the chassis show the manufacturing date as June 1969! Fantastic tube which these pictures really don't do justice to.

This sticker is intriguing. Most sets in the UK of this vintage had "live" chassis working, that is one side of the chassis tied to the neutral of the supply, and this has a warning sticker to that effect, but the set doesn't have this! It's a fully isolated design!

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