Well stated Brett. Mike(y) W3SLK ----- Original Message ----- From: "Brett gazdzinski" <[EMAIL PROTECTED]> To: "'Discussion of AM Radio'" <amradio@mailman.qth.net> Sent: Monday, January 09, 2006 6:55 PM Subject: RE: [AMRadio] Millen High Voltage Connectors
What is wrong with ceramic feedthroughs? I don't think I like the idea of using RF connectors for high voltage, what happens if you or someone else mix it up with RF antenna or output stuff? Brett N2DTS -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Ed Swynar Sent: Monday, January 09, 2006 4:01 PM To: Discussion of AM Radio; [EMAIL PROTECTED] Subject: Re: [AMRadio] Millen High Voltage Connectors Hi Dave, I solved the problem of HV B+ arc-overs here by exclusively using NOTHING but good-quality SO-239 coax receptacles, & RG-8 coax lines for the B+ leads, terminated in good-quality PL-259's... Works like the proverbial charm --- have yet to encounter ANY arc-over failures since adopting this approach universally at my station in the late 70's... ~73~ Eddy VE3CUI - VE3XZ PS: Emphasis on the words "...good-quality" --- NONE OF THAT CHINESE JUNK here!!! ----- Original Message ----- From: "david knepper" <[EMAIL PROTECTED]> To: <amradio@mailman.qth.net>; <[EMAIL PROTECTED]> Sent: Monday, January 09, 2006 3:50 PM Subject: [AMRadio] Millen High Voltage Connectors > My homebrew transmitter, designed by Stan, W3TGR now a silent key, is > going through exhaustive and often frustrating testing. Stan used lots of > shielded wire - you know the Belden stuff that is deteriorating over time > with brittle insulation on the wire. I had to replace several leads because > the center conductor was shorting to ground when the insulation became > brittle. So it goes ... > > Today, I thought that I had finally debugged the unit - pair of 813's > modulated by 805's - but I heard the troubling sound of high voltage to > ground. Measuring the Millen connectors to ground revealed a short. Here > the Millen connectors on the modulator were arcing to ground on the > secondary side of the modulation transformer running from the high voltage > through the secondary winding to the PA amplifier. I am using those light > tan units that are supposed to be better than the red connectors. Stan used > these connectors on the PA amplifier, the modulator deck, and the high > voltage power supply. > > I suppose that under modulation that the peaks exceeded the voltage rating > of the Millen connectors. Once before many years ago, I had the same > problem. However, these connectors are often used in homebrew construction > projects as described in the ARRL handbook. > > Any ideas out there other than to go with ceramic feedthrough insulators. > > Perhaps, it is because of their age and the insulation is breaking down. > Who knows! > > Thanks > > Dave, W3ST > Publisher of the Collins Journal > Secretary to the Collins Radio Association > www.collinsra.com - the CRA Website > Now with PayPal > CRA Nets: 3805 Khz every Monday at 8 PM EST > and 14255 every Saturday at 12 Noon EST > > > ______________________________________________________________ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb > ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net AMfone Website: http://www.amfone.net AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb
