7z4 tube in place of 7y4 are they compatible - Printable Version
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7z4 tube in place of 7y4 are they compatible - Derek38 - 12-18-2019
In my 41-608 I just noticed that someone substituted a 7z4 tube for a 7y4 will that cause a problem?
RE: 7z4 tube in place of 7y4 are they compatible - Ron Ramirez - 12-18-2019
Yes - the 7Z4 has a higher heater current (0.9A) than the 7Y4 (0.5A). This will stress the power transformer. You don't want to stress a nearly 80 year old power transformer if you can avoid it.