Jacques, Jim, Thanks for the replies.
I didn't check C606 or C608 so I have something I need to do now! Hopefully that'll get the regulator back up to 180v. Thanks again, Barry - N4BUQ ----- Original Message ----- > From: "n4buq" <[email protected]> > To: "R-390 Mailing List" <[email protected]> > Sent: Saturday, November 12, 2022 8:58:33 PM > Subject: R390 B+ Expected Tolerance > I discovered that the regulated B+ is running about 175v instead of 180v in my > R390. I found R625 had drifted from 1k to 1.2k and, since I think that was > originally a 1%, I replaced it. I now get very close to 3.7k at the cathode > of > V609; however, that didn't change the regulated voltage. > > I have five 5651s and except for one of them, virtually any two will produce > 175v. If that fifth tube is in place, I get about 185v. According to my > Hickok 752A, the fifth one appears to have a different current draw at its > regulating voltage and that might account for the difference. > > I have a spare 6082 that I've tried swapping in either socket with no > differences there either. > > Running at 115VAC input and getting close to 300v unregulated input to the > regulator. > > It leaves me curious as to how close to 180v is within specification. I've > searched the manuals and I can't seem to find a tolerance for that. Anyone > know? > > Thanks, > Barry - N4BUQ ______________________________________________________________ R-390 mailing list Home: http://mailman.qth.net/mailman/listinfo/r-390 Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
