KUBA PORTA-COLOUR

< Back

The trouble with this I lin. transportable colour set, which
also seems to be known as the Granada Colourette, is no
luminance. I’ve tried a new PCL200 luminance output valve
without success. The fault started with it taking about ten
minutes for the luminance to appear. Then after a few days
the luminance packed up completely. Colour is still present
– the set uses colour -difference drive.
Amongst the many unusual features of this set is the fact
that the luminance drive is a.c. coupled to the common c.r.t.
cathodes (the tube is an in -line gun type), with no clamping.
Also the luminance delay line comes after the luminance
output pentode, i.e. between the pentode and the c.r.t.
cathodes. The delay line itself is a possible offender, and can
be checked by simply shorting it out with a piece of wire.
Otherwise, check back from the c.r.t. cathodes, including
the coupling capacitor and the resistors in the luminance
output stage. We’ve known the fault to be due to a defective
output connection on the board.

Table of Contents

Leave a comment

I have read the privacy policy and accept
Read our privacy policy

This form collects your name, email and content so that we can keep track of the comments placed on the website. For more info check our privacy policy where you will get more info on where, how and why we store your data.

This site uses Akismet to reduce spam. Learn how your comment data is processed.