{"id":4937,"date":"2015-02-23T09:59:00","date_gmt":"2015-02-22T22:59:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2015\/02\/23\/parasitic-anguish-on-40-then-homebrew-transceiver-heard-by-homebrew-receiver-with-a-pto\/"},"modified":"2025-07-21T18:05:42","modified_gmt":"2025-07-21T08:05:42","slug":"parasitic-anguish-on-40-then-homebrew-transceiver-heard-by-homebrew-receiver-with-a-pto","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2015\/02\/23\/parasitic-anguish-on-40-then-homebrew-transceiver-heard-by-homebrew-receiver-with-a-pto\/","title":{"rendered":"Parasitic Anguish on 40 then&#8230;  Homebrew Transceiver Heard by Homebrew Receiver (with a PTO!)"},"content":{"rendered":"<p><iframe loading=\"lazy\" allowfullscreen=\"\" frameborder=\"0\" height=\"248\" src=\"https:\/\/www.youtube.com\/embed\/emsKg5n5-0c?rel=0\" width=\"440\"><\/iframe><\/p>\n<p> <b>Oh man, I was struggling yesterday. I guess I had been lulled into a false sense of security by the phenomenal ease with which I had put my BITX 17 on the air, then added a 120 watt amplifier, all without any sign of the dreaded feedback and parasitic oscillations that had plagued almost all of my previous projects. So when I decided to add the low pass filter and the switching\/relay arrangements needed to use the amplifier with my BITX 20\/40 rig, I kind of expected a similar trouble-free experience. <\/b><br \/> <b><br \/><\/b> <b>WRONG! And you know what? I think guys on 40 and 20 are a bit less forgiving and collegial than the folks on 17. As I struggled to exorcise the transceiver, I&#8217;d make some changes then hopefully go out onto the airwaves and call CQ, looking for a signal report. Well, I got them. Many were not accompanied by call signs. I&#8217;d be in contact with someone who was trying to help, and &#8212; as we were trying to figure out what it might be &#8212; we&#8217;d be bombarded with harsh, sometimes angry, anonymous commentary: &#8220;YOU&#8217;RE 20 kcs WIDE!&#8221; &#8220;Are you on AM?&#8221; &#8220;You have a CARRIER!&#8221; One fellow scornfully told me &#8220;That little QRP rig of yours is not ready for prime time.&#8221; Ouch. (I didn&#8217;t realize we were on prime time. Isn&#8217;t this AMATEUR radio?) <\/b><br \/> <b><br \/><\/b> <b>Others would answer my CQ by announcing that I was &#8220;on the wrong frequency.&#8221; Others would respond (off frequency) and tell me I was distorted &#8212; I&#8217;d ask them to tune me in, then they would say, &#8220;Oh yea, you are OK &#8212; you were just on the wrong frequency.&#8221; Some of these guys seemed to be under the impression that there are &#8220;channels&#8221; on 40 meters. It was a real disheartening mess.<\/b><br \/> <b><br \/><\/b> <b>Then came the saving grace. I got the e-mails that appear below. WOW! My faith in ham radio was renewed! In the 18 months that I&#8217;ve been running the BITX rigs, I&#8217;ve never once worked another station using a homebrew rig. But Rick and I were 3\/4 of the way there yesterday. And he was using a direct conversion receiver of his own design, with a PTO in an enclosure made from &#8220;flattened out tin-plated food tins.&#8221; Fantastic! It was as if the radio gods had arranged all this to pull me out of the depths of parasitic despair! Thanks Rick! A video of his receiver picking up my BITX 20\/40 appears above. <\/b><br \/> <b><br \/><\/b> <b>Pete and I will talk about the actual troubleshooting in the next podcast. I am HOPING to have it fixed by then. I may have to sacrifice some chickens to Papa Legba.&#8221; <\/b><br \/> <b><br \/><\/b> <b>&#8230;&#8230;&#8230;&#8230;&#8230;.<\/b><br \/> <b><br \/><\/b> <b>Bill,<\/p>\n<p> I&#8217;m a long-time SolderSmoke podcast listener, and today one of my ham radio dreams came true.<\/p>\n<p> I was listening to 40 meters today on my homebrew direct conversion receiver, and I heard your call. At first I didn&#8217;t believe it was you, but there you were. <\/p>\n<p> At first I just sat there dumbfounded, just listening, but soon realized that I should make a video of this &#8220;rare DX&#8221; (rare DX for me hi hi), and post it on YouTube for you to review.<\/p>\n<p> My apologies for the low audio in the video. I was using my iPhone and its inboard mic leaves a lot to be desired, but the best audio of you is at 0:13, 0:50, and again at 2:12 into the video.<\/p>\n<p> Heard you on 7.16 MHz, Sunday 2-22-2015 at 10:15 a.m. local east-coast time (15:15 UTC).<\/p>\n<p> I&#8217;m located in Manchester Maryland (North &#8211; Central Maryland). My homebrew 40 meter rig is a PTO tuned direct conversion receiver with all discrete components. My antenna is a simple wire dipole about 6 feet above the ground just outside by workroom window.<\/p>\n<p> Below are links to the YouTube video of your QSO , and the schematic the DSB transceiver that you were received on. The rig is one that I designed, based on the published works of many home-brewers from the web. I call it the Lakeside 40 (in homage to Peter Parker&#8217;s Beach 40 transceiver).<\/p>\n<p> So far I only completed the receiver section, and hope to complete the transmitter sometime this summer so I can use the rig at Lake Marburg (at Codorus State Park in PA), thus the &#8220;Lakeside&#8221; in the rig&#8217;s name.<br \/><a href=\"http:\/\/youtu.be\/emsKg5n5-0c\" rel=\"nofollow\" target=\"_blank\"><br \/> http:\/\/youtu.be\/emsKg5n5-0c<\/a><\/p>\n<p><a href=\"http:\/\/www.remmepark.com\/circuit6040\/lakeside40.gif\" id=\"yui_3_16_0_1_1424640685494_31139\" rel=\"nofollow\" target=\"_blank\">http:\/\/www.remmepark.com\/circuit6040\/lakeside40.gif<\/a><\/p>\n<p> 73<br \/>Rick &#8211; N3FJZ<\/b><br \/> <b><br \/><\/b> <b><br \/><\/b> <b>Bill,<br clear=\"none\" \/><br clear=\"none\" \/>Yes, what a coincidence with the PTO! That&#8217;s the same WA6OTP PTO design <br clear=\"none\" \/>I based my PTO on.<br clear=\"none\" \/><br clear=\"none\" \/>I created a webpage tonight(very much a work in progress) so you can see <br clear=\"none\" \/>the details of how I constructed my PTO in the Lakeside 40, as well as <br clear=\"none\" \/>my rendition of a BITX 20. Click the [Permeability Tuned Oscillator], or <br clear=\"none\" \/>[My rendition of a Bitx 20] links on the left of the page.<br clear=\"none\" \/><br clear=\"none\" \/>The webpage is here:<br clear=\"none\" \/>[<a href=\"http:\/\/www.remmepark.com\/circuit6040\/index.html\" shape=\"rect\" target=\"_blank\">http:\/\/www.remmepark.com\/circuit6040\/index.html<\/a>]<br clear=\"none\" \/><br clear=\"none\" \/>The ground plane for the Manhattan construction (and RF tight enclosure <br clear=\"none\" \/>for the PTO) are made from flattened out tin plated food cans, and the <br clear=\"none\" \/>coil-form for the PTO is cut from Masonite wall panel material with my <br clear=\"none\" \/>scroll saw.<br clear=\"none\" \/><br clear=\"none\" \/>Don&#8217;t get discouraged from the less than enthusiastic response from the <br clear=\"none\" \/>others about your signal, pay them no mind; I&#8217;m sure they simply didn&#8217;t <br clear=\"none\" \/>realize the significance of what it represented. To me, your signal was <br clear=\"none\" \/>the most perfect signal I have ever heard. It was perfect because I <br clear=\"none\" \/>know (from your pod-casts, and my attempts at homebrew) what it took for <br clear=\"none\" \/>it to be produced. Its existence, and the fact that I successfully <br clear=\"none\" \/>received it on my little homebrew rig too, represents the fundamental <br clear=\"none\" \/>core foundation of Amateur radio; experimentation, building equipment <br clear=\"none\" \/>with your own hands from scratch, expanding ones knowledge in the radio <br clear=\"none\" \/>art, and most important, having fun and enjoying the excitement that <br clear=\"none\" \/>comes from using gear that *you* built.<br clear=\"none\" \/><br clear=\"none\" \/>I cannot put into words how significant hearing your signal was for me <br clear=\"none\" \/>today &#8211; thank you! My biggest regret is that I didn&#8217;t have a means of <br clear=\"none\" \/>transmitting yet on 40 meters, and my Bitx 20 is not ready yet, <\/b><br \/> <b>perhaps in the future we can have homebrew to homebrew QSO&#8217;s <br clear=\"none\" \/>where we can fine-tune our designs and tweak things (however we&#8217;ll have <br clear=\"none\" \/>go above 7.175 MHz, or 14.225 MHz since I only hold a General ticket at <br clear=\"none\" \/>the moment).<br clear=\"none\" \/><br clear=\"none\" \/>Rick<br clear=\"none\" \/>N3FJZ.<\/b><br \/> <b><br \/><\/b> <img loading=\"lazy\" decoding=\"async\" alt=\"PTO another view.\" height=\"300\" src=\"https:\/\/www.homebrewradio.us\/blog\/wp-content\/uploads\/2015\/02\/img_2042_std.jpg\" width=\"400\" \/><\/p>\n<div style=\"text-align: left;\"> Rick&#8217;s PTO<\/div>\n<p> Our book: &#8220;SolderSmoke &#8212; Global Adventures in Wireless Electronics&#8221; <a href=\"http:\/\/soldersmoke.com\/book.htm\">http:\/\/soldersmoke.com\/book.htm<\/a> Our coffee mugs, T-Shirts, bumper stickers: <a href=\"http:\/\/www.cafepress.com\/SolderSmoke\">http:\/\/www.cafepress.com\/SolderSmoke<\/a> Our Book Store: <a href=\"http:\/\/astore.amazon.com\/contracross-20\">http:\/\/astore.amazon.com\/contracross-20<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Oh man, I was struggling yesterday. I guess I had been lulled into a false sense of security by the phenomenal ease with which I had put my BITX 17 on the air, then added a 120 watt amplifier, all without any sign of the dreaded feedback and parasitic oscillations that had plagued almost all &hellip; <a href=\"https:\/\/www.homebrewradio.us\/blog\/2015\/02\/23\/parasitic-anguish-on-40-then-homebrew-transceiver-heard-by-homebrew-receiver-with-a-pto\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Parasitic Anguish on 40 then&#8230;  Homebrew Transceiver Heard by Homebrew Receiver (with a PTO!)&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":4938,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[44,28,103,25],"tags":[],"class_list":["post-4937","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-17-meters","category-bitx20","category-knack-stories","category-troubleshooting"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4937","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=4937"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4937\/revisions"}],"predecessor-version":[{"id":4939,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/4937\/revisions\/4939"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/4938"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=4937"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=4937"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=4937"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}