Hi,
If you come across a power valve with a UX or B5 or B7 base (hollow pins) and they seem to have no emission, resoldering the pins often effects a cure, I'm sure we've all done this. Occasionally though, this doesn't cure the problem.
I recently bought a pair of DA42's listed as untested apart from heaters - one was fine, the other failed to work. Resoldering didn't work either, so I tried a 'trick' that had worked in the past.
Use a piercing saw to cut across the pin, part way through the pin, about 3mm from its end. Then cut a slot from the pin tip to meet the first cut - carefully open out the pin to allow access to the electrode wire, often found unsoldered internally - scrape away the inside surface of the pin and the wire - use flux and resolder making a firm joint - bend the opened pin back to shape and reflow.
With luck you will have a working valve.
The DA42 responded well and is now working fine!
This may seem a little severe but has saved several valves over the years🙂
If you come across a power valve with a UX or B5 or B7 base (hollow pins) and they seem to have no emission, resoldering the pins often effects a cure, I'm sure we've all done this. Occasionally though, this doesn't cure the problem.
I recently bought a pair of DA42's listed as untested apart from heaters - one was fine, the other failed to work. Resoldering didn't work either, so I tried a 'trick' that had worked in the past.
Use a piercing saw to cut across the pin, part way through the pin, about 3mm from its end. Then cut a slot from the pin tip to meet the first cut - carefully open out the pin to allow access to the electrode wire, often found unsoldered internally - scrape away the inside surface of the pin and the wire - use flux and resolder making a firm joint - bend the opened pin back to shape and reflow.
With luck you will have a working valve.
The DA42 responded well and is now working fine!
This may seem a little severe but has saved several valves over the years🙂
