The solder has melted inside the pin. When cold or just looking at it all checks and looks well. JUST RESOLDER THE FILAMENT PINS! Lee, w0vt, Houston
Subject: [drakelist] L4B tube > > In my L4B amplifier, the tubes burn nicely for a short time, then one of the > tubes' filaments go out. I removed the tubes and switched them. Same tube > goes out after abit. Took that tube out again, checked filament to filament > pins, "zero" on the Simpson 260. Also checked for a filament to grid short, > (tapping tube didn't change reading) and that reading was "infinity". So the > tube is OK, until it heats up. The solder blob on the pin bottoms are OK. > > I think the filaments are getting HOT while I'm transmitting, and possibly a > 'fracture' in the filament somewhere, getting hot, expands, then when I'm in > the 'listening' mode long enough, the fracture presents itself as an OPEN in > the filament line. Comments welcome. > 73, Gerald, KB7QQ ---------------------------------------------------------------------- Submissions: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] - subscribe drakelist in body Unsubscribe: [EMAIL PROTECTED] - unsubscribe drakelist in body Hopelessly Lost: [EMAIL PROTECTED] - help in body of message Brought to you courtesy of TLCHost.net http://www.tlchost.net/ ----------------------------------------------------------------------
