2020年12月24日 · Looking to purchase a known good (tested) 6R7 tube.

2021年8月24日 · I would pull the first audio tube, the 6R7, and check it's B+ that way. If it is still 27 V then obviously something still in the radio is the culprit. It might be safer to Ohm the B+ to ground with the radio unpowered and the 6R7 removed in fact. The B+ that the circuit is running from is about 280 V if you average the two audio plate voltages.

6R7 - mine *looked* OK but had some strange heater leakage to the diodes that was hard to touble-shoot. Showed up as ac hum on the audio. Final decision was done by using a socket extender and running the heater on dc! Replament tube cured it.

2005年12月15日 · Hi - Another in my inherited collection is a BC-342 receiver (built in power supply). Things appear to have been opened up (occasional missing screws on cove…

2016年5月30日 · Of the tubes in your radio, the 6R7 (AVC rectifier and amp), 6B8 (1st IF) and 5X4 (rectifier) weren't as commonly used as the other tubes, so they may be a little harder to find, but will probably cost no more to replace than the other tubes. The 6U5 eye tube was very commonly used, but the display screens wore out after a decade or so.