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About struts

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  • Birthday 07/29/1966


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  1. Many thanks @spritzer. 1M/5M in the divider would take it down to 483V. Is that the right ballpark or would you take it down even further (this is for a T2)?
  2. Quick questions regarding a voltage divider to take a 580V Stax bias line down to 520V for HE90 (I believe the spec is 500V but I remember reading a post once that @spritzer had measured a number of HEV90s and found the average to be closer to 520V). - I assume that the difference in bias is somehow related to differences in the membrane construction between the two, maybe the coating? - Is there a real risk of damaging HE90s running straight off Stax bias? I.e. can the additional potential actually lead to the membrane making contact with the grid? Does anybody have any practi
  3. These kind of problems are fascinating. IME there are two ways to approach troubleshooting them: cause-and-effect (work the list from most likely theoretical cause on down) and logical elimination (what's changed? Voltage, PS itself (grounding etc), umbilical(s), etc.) Out of interest was it electrical or mechanical* hum? Assume the former since it was channel specific? * of course we all know the reason transformers hum - because they don't know the words.. ?
  4. Yup, unfortunately mine look like the suspect ones . I'll see if I can get them desoldered over the weekend and send them off to you, Craig. I hope Dalbani have stocks, I noticed you cleaned out Vintage Parts!
  5. Inu, How did you determine they were counterfeit? Just by the measurements or are there any other telltale signs? I noted Craigs comments about the lead frames above, I wonder if this is a common characteristic of counterfeit parts? If so, I wonder why? Seems silly to go to all the trouble of producing such exact copies and then making such an easily identifiable mistake..
  6. That's an extremely kind offer Craig. Everything is soldered in place but I haven't started testing as I haven't got the umbilicals made up yet. Sounds like for the sake of a couple more weeks it would be wise to pull the 3675s and send them over to you. Rather that than risk silicon genocide and a protracted and complex troubleshoot. Please could you PM me your address?
  7. Craig, Were any of your 'suspect' C3675s from Dalbani? Where have you reordered from? If Dalbani has been supplying duff silicon I'm in trouble, sourced nearly all silicon from them...
  8. Good point Craig, I was thinking about the receptacle-to-chassis interface but not the interfaces between the chassis plates themselves. Of course the WHOLE chassis must be tied to safety ground. Doh!
  9. Sorry people. I seem to be suffering massive late-night brain-fade. I have figured out the answers to most of my questions. Now bed.
  10. Hi guys and seasons greetings, After a very long hiatus caused by work and waiting for my RK50 which has FINALLY arrived I am 99% ready with the build and almost ready to start testing. Few questions regarding final assembly: 1. Wiring the umbilicals. What are people doing here (in terms of assigning wires to pins)? I guess it's not too important that power supplies are interchangeable between units (at least not for me up here in Sweden!) but there must be some arrangement that works better/best with this mixture of high and low voltages, AC and DC. 2. Related to the above I was t
  11. Sorry, just back from a week/long business trip to India. Must sleep now but I'll get on it as soon as I wake up.
  12. Thanks spritzer. Is A, B or C best for this application?
  13. I assume you mean you're avoiding the LSK389 which seems to be real hard to get ahold of. Are you going with K170s? If so, which ones? Also, please specify BL or GR etc. for 2SC parts where it's critical.
  14. Good news and bad news. The good news is that onlinecomponents can supply the RK50 for $655 , the bad news is that the lead time is 12 weeks not 8 Meanwhile my build is s l o w l y progressing...amp, ps...amd yes, I realized the diode needs flipping and the resistors crossing...
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