Hi Alex, About your HV regulator output running at 171V: funny, because it's usually the reverse (running higher than 180V). The only thing that can cause that, IMHO, is leakage in the C606. If it is that, the control grid of the V607 goes higher than it is supposed to be, forcing the regulator output to run low. Not having a reliable tube tester when "playing" with a R-390 is a difficult situation. Try to locate someone that have one who can help you. About the other components in the HV regulator circuit, and all the other ones (audio stages) in the same module: do not trust any. The temperature goes so high in the chassis that IMHO, they all need to be changed for new ones, not only the 47 ohms resistors. Once all those will be replaced by modern components, the 180V output should be good, unless the 5651 needs to be replaced also.
73, Jacques, VE2JFE in Montreal Hello All, Last night I was able to slowly bring the set up on my variac and - it works! I was able to tune in a few stations, and everything appears to function, even the antenna relay! I had to replace one dead 6082 tube in the regular circuit. B+ measures 171.1 volts steadily at the J601 test point on the side of the chassis, with basically no fluctuation. Is 171 volts this too low for the B+? According to the manual it should be 180 volts. Could this be caused by weaker rectifier or VR tubes? What is next? My thought was to replace the 8 47ohm resistors - 4 each in the power supply and audio modules. Unfortunately I do not have a reliable tube tester. Thanks, -Alex ______________________________________________________________ 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
