<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_ym19_1_1526431968716_31626">Bill,</div><div id="yui_3_16_0_ym19_1_1526431968716_31625">Electrolytic caps have considerable internal impedance at RF. It is common practice to parallel a 0.1 with a large value electrolytic cap to keep the RF impedance low. The 30 mfd might be there to help with a aging cap. However, I would put the small cap back to keep RF on the power supply to a minimum. That prevents all kinds of problems including instability and feedback.</div><div id="yui_3_16_0_ym19_1_1526431968716_31879">Al</div><div id="yui_3_16_0_ym19_1_1526431968716_31880">WB9UVJ<br></div><div id="yui_3_16_0_ym19_1_1526431968716_31500"><span></span></div> <div class="qtdSeparateBR"><br><br></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 13px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"><font size="2" face="Arial"> On Tuesday, May 15, 2018 11:00 AM, "heath-request@puck.nether.net" <heath-request@puck.nether.net> wrote:<br></font></div> <br><br> <div class="y_msg_container"><div dir="ltr">Send Heath mailing list submissions to<br></div><div dir="ltr"> <a ymailto="mailto:heath@puck.nether.net" href="mailto:heath@puck.nether.net">heath@puck.nether.net</a><br></div><div dir="ltr"><br></div><div dir="ltr">To subscribe or unsubscribe via the World Wide Web, visit<br></div><div dir="ltr"> <a href="https://puck.nether.net/mailman/listinfo/heath" target="_blank">https://puck.nether.net/mailman/listinfo/heath</a><br></div><div dir="ltr">or, via email, send a message with subject or body 'help' to<br></div><div dir="ltr"> <a ymailto="mailto:heath-request@puck.nether.net" href="mailto:heath-request@puck.nether.net">heath-request@puck.nether.net</a><br></div><div dir="ltr"><br></div><div dir="ltr">You can reach the person managing the list at<br></div><div dir="ltr"> <a ymailto="mailto:heath-owner@puck.nether.net" href="mailto:heath-owner@puck.nether.net">heath-owner@puck.nether.net</a><br></div><div dir="ltr"><br></div><div dir="ltr">When replying, please edit your Subject line so it is more specific<br></div><div dir="ltr">than "Re: Contents of Heath digest..."<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Today's Topics:<br></div><div dir="ltr"><br></div><div dir="ltr"> 1. DX40 (Bill)<br></div><div dir="ltr"> 2. DX-40 (Mike)<br></div><div dir="ltr"> 3. Re: DX40 (Kenneth G. Gordon)<br></div><div dir="ltr"> 4. DX-40 (Mike)<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">----------------------------------------------------------------------<br></div><div dir="ltr"><br></div><div dir="ltr">Message: 1<br></div><div dir="ltr">Date: Mon, 14 May 2018 14:43:37 -0400<br></div><div dir="ltr">From: Bill <<a ymailto="mailto:hony53@aol.com" href="mailto:hony53@aol.com">hony53@aol.com</a>><br></div><div dir="ltr">To: <a ymailto="mailto:Heath@puck.nether.net" href="mailto:Heath@puck.nether.net">Heath@puck.nether.net</a><br></div><div dir="ltr">Subject: [Heath] DX40<br></div><div dir="ltr">Message-ID: <<a ymailto="mailto:1635ff710c1-1798-1e45@webjas-vaa024.srv.aolmail.net" href="mailto:1635ff710c1-1798-1e45@webjas-vaa024.srv.aolmail.net">1635ff710c1-1798-1e45@webjas-vaa024.srv.aolmail.net</a>><br></div><div dir="ltr">Content-Type: text/plain; charset="utf-8"<br></div><div dir="ltr"><br></div><div dir="ltr">Just acquired a DX 40, not working (of course).<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Pretty clean inside, but at least 1 obvious problem, the plate connection at the top of the tube is broken.<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">The other (possible) problem is capacitor 23-11 (0.1 uf, 600v) has been replaced with a 30uf cp.<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Was this a beneficial mod or an error?<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Thanks for any help.<br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">Bill, N2KPE<br></div><div dir="ltr">-------------- next part --------------<br></div><div dir="ltr">An HTML attachment was scrubbed...<br></div><div dir="ltr">URL: <<a href="https://puck.nether.net/pipermail/heath/attachments/20180514/2ff55fd0/attachment-0001.html" target="_blank">https://puck.nether.net/pipermail/heath/attachments/20180514/2ff55fd0/attachment-0001.html</a>><br></div><div dir="ltr"><br></div><div dir="ltr">------------------------------<br></div><div dir="ltr"><br></div><div dir="ltr">Message: 2<br></div><div dir="ltr">Date: Mon, 14 May 2018 21:42:10 +0000<br></div><div dir="ltr">From: Mike <<a ymailto="mailto:MLF42@Q.com" href="mailto:MLF42@Q.com">MLF42@Q.com</a>><br></div><div dir="ltr">To: Heath <<a ymailto="mailto:Heath@puck.nether.net" href="mailto:Heath@puck.nether.net">Heath@puck.nether.net</a>><br></div><div dir="ltr">Subject: [Heath] DX-40<br></div><div dir="ltr">Message-ID: <<a ymailto="mailto:emc9b121f7-1740-40cc-95a7-380ae6155374@mike-pc" href="mailto:emc9b121f7-1740-40cc-95a7-380ae6155374@mike-pc">emc9b121f7-1740-40cc-95a7-380ae6155374@mike-pc</a>><br></div><div dir="ltr">Content-Type: text/plain; charset="utf-8"; Format="flowed"<br></div><div dir="ltr"><br></div><div dir="ltr">Bill...I wouldn't worry about the cap...but fixing the plate cap would <br></div><div dir="ltr">be a good idea...Depending on when it was last powered up, I'd bring it <br></div><div dir="ltr">up slow with a variac or a light bulb in series with the AC mains...<br></div><div dir="ltr"><br></div><div dir="ltr">Mike AA7WU<br></div><div dir="ltr"><br></div><div dir="ltr">---<br></div><div dir="ltr">This email has been checked for viruses by AVG.<br></div><div dir="ltr"><a href="http://www.avg.com/" target="_blank">http://www.avg.com</a><br></div><div dir="ltr">-------------- next part --------------<br></div><div dir="ltr">An HTML attachment was scrubbed...<br></div><div dir="ltr">URL: <<a href="https://puck.nether.net/pipermail/heath/attachments/20180514/33c208ef/attachment-0001.html" target="_blank">https://puck.nether.net/pipermail/heath/attachments/20180514/33c208ef/attachment-0001.html</a>><br></div><div dir="ltr"><br></div><div dir="ltr">------------------------------<br></div><div dir="ltr"><br></div><div dir="ltr">Message: 3<br></div><div dir="ltr">Date: Mon, 14 May 2018 16:20:47 -0700<br></div><div dir="ltr">From: "Kenneth G. Gordon" <<a ymailto="mailto:kgordon2006@frontier.com" href="mailto:kgordon2006@frontier.com">kgordon2006@frontier.com</a>><br></div><div dir="ltr">To: Bill via Heath <<a ymailto="mailto:heath@puck.nether.net" href="mailto:heath@puck.nether.net">heath@puck.nether.net</a>><br></div><div dir="ltr">Subject: Re: [Heath] DX40<br></div><div dir="ltr">Message-ID: <<a ymailto="mailto:5AFA19CF.25373.1A5FCFD@kgordon2006.frontier.com" href="mailto:5AFA19CF.25373.1A5FCFD@kgordon2006.frontier.com">5AFA19CF.25373.1A5FCFD@kgordon2006.frontier.com</a>><br></div><div dir="ltr">Content-Type: text/plain; charset=US-ASCII<br></div><div dir="ltr"><br></div><div dir="ltr">On 14 May 2018 at 14:43, Bill via Heath wrote:<br></div><div dir="ltr"><br></div><div dir="ltr">> <br></div><div dir="ltr">> Just acquired a DX 40, not working (of course).<br></div><div dir="ltr">> <br></div><div dir="ltr">> Pretty clean inside, but at least 1 obvious problem, the plate connection at the top of the tube is <br></div><div dir="ltr">> broken.<br></div><div dir="ltr"><br></div><div dir="ltr">Do you mean the top-cap on the tube is broken off? Or just the wire to the plate connector?<br></div><div dir="ltr"><br></div><div dir="ltr">If it is the tube, toss it and get another one.<br></div><div dir="ltr"><br></div><div dir="ltr">> The other (possible) problem is capacitor 23-11 (0.1 uf, 600v) has been replaced with a 30uf cp.<br></div><div dir="ltr">> <br></div><div dir="ltr">> Was this a beneficial mod or an error?<br></div><div dir="ltr"><br></div><div dir="ltr">Hmmm....my manual does not show capacitor 23-11 in the parts list, nor a capacitor of 0.1 <br></div><div dir="ltr">uF, 600V anywhere. My parts list does show a 2 MF 200 V capacitor part number 23-17. <br></div><div dir="ltr"><br></div><div dir="ltr">Maybe yours was a later factory mod. Where does this appear? If it is in the modulator area, <br></div><div dir="ltr">it may be the timing capacitor for the controlled carrier modulation system.<br></div><div dir="ltr"><br></div><div dir="ltr">If it is, I would think that 30 uF is much too large. There are some enhancements for <br></div><div dir="ltr">controlled-carrier modulation on an AM site. Perhaps you will find something useful there.<br></div><div dir="ltr"><br></div><div dir="ltr">My first transmitter was a DX-35. I have two now, and a pair of DX-40s. If I can help, holler.<br></div><div dir="ltr"><br></div><div dir="ltr">Ken W7EKB<br></div><div dir="ltr"><br></div><div dir="ltr">---<br></div><div dir="ltr">This email has been checked for viruses by Avast antivirus software.<br></div><div dir="ltr"><a href="https://www.avast.com/antivirus" target="_blank">https://www.avast.com/antivirus</a><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">------------------------------<br></div><div dir="ltr"><br></div><div dir="ltr">Message: 4<br></div><div dir="ltr">Date: Tue, 15 May 2018 04:14:10 +0000<br></div><div dir="ltr">From: Mike <<a ymailto="mailto:MLF42@Q.com" href="mailto:MLF42@Q.com">MLF42@Q.com</a>><br></div><div dir="ltr">To: Heath <<a ymailto="mailto:Heath@puck.nether.net" href="mailto:Heath@puck.nether.net">Heath@puck.nether.net</a>><br></div><div dir="ltr">Subject: [Heath] DX-40<br></div><div dir="ltr">Message-ID: <<a ymailto="mailto:em874600c8-01d1-44b8-a35e-d3d6892ebd05@mike-pc" href="mailto:em874600c8-01d1-44b8-a35e-d3d6892ebd05@mike-pc">em874600c8-01d1-44b8-a35e-d3d6892ebd05@mike-pc</a>><br></div><div dir="ltr">Content-Type: text/plain; charset="utf-8"; Format="flowed"<br></div><div dir="ltr"><br></div><div dir="ltr">Ken...WRT the DX-40...I think Bill is referring to C-23 in the mic input <br></div><div dir="ltr">circuit...<br></div><div dir="ltr"><br></div><div dir="ltr">Mike<br></div><div dir="ltr"><br></div><div dir="ltr">---<br></div><div dir="ltr">This email has been checked for viruses by AVG.<br></div><div dir="ltr"><a href="http://www.avg.com/" target="_blank">http://www.avg.com</a><br></div><div dir="ltr">-------------- next part --------------<br></div><div dir="ltr">An HTML attachment was scrubbed...<br></div><div dir="ltr">URL: <<a href="https://puck.nether.net/pipermail/heath/attachments/20180515/e5755877/attachment-0001.html" target="_blank">https://puck.nether.net/pipermail/heath/attachments/20180515/e5755877/attachment-0001.html</a>><br></div><div dir="ltr"><br></div><div dir="ltr">------------------------------<br></div><div dir="ltr"><br></div><div dir="ltr">Subject: Digest Footer<br></div><div dir="ltr"><br></div><div dir="ltr">_______________________________________________<br></div><div dir="ltr">Heath mailing list<br></div><div dir="ltr"><a ymailto="mailto:Heath@puck.nether.net" href="mailto:Heath@puck.nether.net">Heath@puck.nether.net</a><br></div><div dir="ltr"><a href="https://puck.nether.net/mailman/listinfo/heath" target="_blank">https://puck.nether.net/mailman/listinfo/heath</a><br></div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr">------------------------------<br></div><div dir="ltr"><br></div><div dir="ltr">End of Heath Digest, Vol 89, Issue 3<br></div><div dir="ltr">************************************<br></div><br><br></div> </div> </div> </div></div></body></html>