UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - GZ34

Argus25 · 16th Oct 2019, 11:54 pm

As noted on another thread I would go for Ruby brand myself, all their rectifiers I have tested and used have been good. I'm not sure where these are sourced, but whoever made them did a very nice job.

I tried some Russian equivalents of the 5u4 once that have an internal construction where springs support the filaments. They looked well constructed and had a similar voltage drop to a 5u4 at the same current, but they flash over at a lower reverse voltage, and it made them unusable in my Argus TV, but for other applications they would probably be fine.

If you want a very low voltage drop valve rectifier go for an 83 mercury vapor rectifier. They used these in American valve testers, so the fluctuations in HT voltages were minimal with different loads , so as to make the calibration as uniform as possible and the HT supply rail very stiff. However RF hash can be a problem, but possibly not a lot more than a silicon rectifier. There is also the 83V high vacuum version.

16th Oct 2019, 11:54 pm	#12
Argus25 No Longer a Member Join Date: Oct 2016 Location: Maroochydore, Queensland, Australia. Posts: 2,679	Re: GZ34 - recommended brands? As noted on another thread I would go for Ruby brand myself, all their rectifiers I have tested and used have been good. I'm not sure where these are sourced, but whoever made them did a very nice job. I tried some Russian equivalents of the 5u4 once that have an internal construction where springs support the filaments. They looked well constructed and had a similar voltage drop to a 5u4 at the same current, but they flash over at a lower reverse voltage, and it made them unusable in my Argus TV, but for other applications they would probably be fine. If you want a very low voltage drop valve rectifier go for an 83 mercury vapor rectifier. They used these in American valve testers, so the fluctuations in HT voltages were minimal with different loads , so as to make the calibration as uniform as possible and the HT supply rail very stiff. However RF hash can be a problem, but possibly not a lot more than a silicon rectifier. There is also the 83V high vacuum version.