ERRATA TIME! In Figure 6-21, the annotations for C327 and C328 are swapped. C328 is a 5nF ceramic disk bypass, while C327 is 100pF mica forming a tuned circuit.
Jacques, did you typo? Figure 6-21 is on page 6-59, not 6-47, at least in my file which says Revision 10, 2006-March-17. Dave Wise ________________________________ From: [email protected] <[email protected]> on behalf of Barry <[email protected]> Sent: Friday, June 28, 2024 1:07 PM To: Jacques Fortin <[email protected]> Cc: R-390 Mailing List <[email protected]> Subject: Re: [R-390] Update on R390A, open question regarding scope and options fir lubrication I just opened the Y2K-R3 document and on page 6-47, Figure 6-21 shows a picture of C327 which appears to be a ceramic disc. Is that a mistake in the Y2K documentation? Apologies if this has already been discussed but I found it odd in light of all this recent conversation regarding C327. Thanks, Barry - N4BUQ > John, unless that you are equipped to test the Micamold cap with 300Vdc > applied > (their manufacturing voltage rating) to confirm that they have less than 10nA > of leakage, wait for the new manufacture 1kV one. > > I believe that the recommendation to change C327 was made because of the > trouble > involved with the RF deck removal to change any of the parts within. > Since then, many original mica caps inside the IF transformers were reported > to > fail (the thunderstorm noise problem). > But here also, they will not ALL exhibit failures, as this is just a > probability. > Failure of the early type "postage stamp" mica caps is essentially due to > their > long-term casing permeability. > Some mica caps were made to never fail, like the Corning Glass Works (CGW) > ones > that have a glass encapsulation. > But as with any electronic equipment ever made, all depended on the cost vs > reliability criteria. > > 73, Jacques, VE2JFE in Montreal > > ______________________________________________________________ > 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 ______________________________________________________________ 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 ______________________________________________________________ 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
