13-10-2016, 03:59 PM
(This post was last modified: 13-10-2016, 04:00 PM by Geordie McBoyne.)
Todays big news is that the set works. As you would expect from a receiver that has an RF amplifier and a two IF amplifier stages sensitivity and selectivity is excellent. Plenty audio power thanks to a pair of 6F6G pentodes. The HT rectifier valve is the unusual metal type 5T4, the example in this set is rather rusty. The 20µF HT reservoir capacitor was found to be useless so for the time being a wire ended electrolytic will be used. A proper can electrolytic is available from the BVWS shop.
However, after a few minutes of use the audio faded away, the 200 volt HT supply dropped to less than 50 volts, the fault turned out to be a almost hidden 0.25µF capacitor going leaky, wax could seen oozing from out of the capacitor ends. It's been clipped out.
The motorised tuning system also works as it should. There are still plenty jobs to do to this set.
Geordie McBoyne.
However, after a few minutes of use the audio faded away, the 200 volt HT supply dropped to less than 50 volts, the fault turned out to be a almost hidden 0.25µF capacitor going leaky, wax could seen oozing from out of the capacitor ends. It's been clipped out.
The motorised tuning system also works as it should. There are still plenty jobs to do to this set.
Geordie McBoyne.
