{"id":9883,"date":"2022-12-08T17:02:55","date_gmt":"2022-12-08T17:02:55","guid":{"rendered":"https:\/\/stevepedwards.today\/ElectronicsStuff\/?p=9883"},"modified":"2025-07-16T21:46:28","modified_gmt":"2025-07-16T20:46:28","slug":"1946-vidor-chanson-cn349-valve-radio-checks","status":"publish","type":"post","link":"https:\/\/stevepedwards.today\/ElectronicsStuff\/1946-vidor-chanson-cn349-valve-radio-checks\/","title":{"rendered":"1946 Vidor Chanson CN349 Valve Radio Checks"},"content":{"rendered":"<p>This old radio was \u00a320 but good condition in a dog charity store. It has a full valve compliment so seemed worth the risk. I don't have much test gear these days, so did what checks I could with what I have and no oscilloscope. I decided to go ahead and do what I can to get this thing in working order at minimal cost based on those results. As I'm not so experienced on valve radios as I am on valve amps I took many pics before detaching any wires to test the mains caps and transformer to see if it was worth proceeding further:<\/p>\n<p><iframe loading=\"lazy\" title=\"1946 Vidor Chanson Valve Radio Pics\" src=\"https:\/\/www.youtube.com\/embed\/q_z4bPJ9yyw\" width=\"1351\" height=\"480\" frameborder=\"0\" allowfullscreen=\"allowfullscreen\"><\/iframe><\/p>\n<p><a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/vidor_chanson_cn349_radio_1946_sm.pdf\">vidor_chanson_cn349_radio_1946_sm.pdf<\/a><\/p>\n<p>I checked the duff states of the capacitor can marked 8uF and 16uF, bubbled mains filter caps for interest (16uf and 24uF on the schematic):<\/p>\n<p><a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180851.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-9889 size-full\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180851.jpg\" alt=\"\" width=\"1000\" height=\"563\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180851.jpg 1000w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180851-300x169.jpg 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180851-768x432.jpg 768w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/a><\/p>\n<p><a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180920.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-9890 size-full\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180920.jpg\" alt=\"\" width=\"1000\" height=\"563\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180920.jpg 1000w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180920-300x169.jpg 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221218_180920-768x432.jpg 768w\" sizes=\"auto, (max-width: 1000px) 100vw, 1000px\" \/><\/a><\/p>\n<p>The cap leads may have been connected to the wrong sides of the choke too - I'll have to check before the new 22uF caps arrive, not that it matters as I have two the same values ordered. I don't have terminal tie strips so still thinking how I'm gonna connect the caps to the rectifier wires...<\/p>\n<p><a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/MainsCaps.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9894\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/MainsCaps.png\" alt=\"\" width=\"1251\" height=\"501\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/MainsCaps.png 1251w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/MainsCaps-300x120.png 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/MainsCaps-1024x410.png 1024w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/MainsCaps-768x308.png 768w\" sizes=\"auto, (max-width: 1251px) 100vw, 1251px\" \/><\/a><\/p>\n<p><iframe loading=\"lazy\" title=\"#339: Basics of a Super-heterodyne Receiver - how it works, and a peek at the signals\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/Vf06HSR4LdY?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>As an aside, here is a good explanation of why 50 Ohms coax is used as a compromise between 30 and 75 Ohms for price, lowest impedance losses and power handling of radio signal Tx\/Rx, when thinking about getting radio signals to this unit as it does not have it's own aerial, so I will look at diff types of aerials to feed it, from a simple loop of wire to RG6 coax and\/or F7 coax connector from the wall sockets etc:<\/p>\n<p><iframe loading=\"lazy\" title=\"Why is Coax 50 Ohms? (#340)\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/I-OnQZJv35I?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>... so WHY some test gear historically has or expects to connect to a 50 Ohm load :<\/p>\n<p><a href=\"https:\/\/youtu.be\/Xb1WO4BLcSQ\">https:\/\/youtu.be\/Xb1WO4BLcSQ<\/a><\/p>\n<p>I took readings for some components and did some calcs for what to expect from this thing based on present tube types power max ratings and the windings ratings:<\/p>\n<p><strong>Total Secondary Windings Power<\/strong><\/p>\n<p>240V x 0.06A = 14.6W +<\/p>\n<p>4V x 2.5A = 10W +<\/p>\n<p>6.3V x 3A = 19W<\/p>\n<p><strong>= 44W<\/strong><\/p>\n<p><strong>Total Primary Winding Current for fuse is about:<\/strong><\/p>\n<p>40W \/ 240V = 1\/4 Amp<\/p>\n<p><strong>Big Iron windings:<\/strong><\/p>\n<p>Primary: 29 Ohms, 108mH<\/p>\n<p>Secondary: 587 Ohms, 9.4H<\/p>\n<p>Rectifier Heater Winding: 0.5 Ohms, 0.01 mH<\/p>\n<p>Valve Heater Winding: 2.18 Ohms, *no H measure<\/p>\n<p>Audio Transformer: 362 Ohms, 8.2H<\/p>\n<p>Choke: 380.6 Ohms, 12H<\/p>\n<p><strong>Importance of visual inspection before even thinking about power up !:<\/strong><\/p>\n<p><a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9903\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731.jpg\" alt=\"\" width=\"1920\" height=\"1080\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731.jpg 1920w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731-300x169.jpg 300w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731-1024x576.jpg 1024w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731-768x432.jpg 768w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/20221211_215731-1536x864.jpg 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><\/a><\/p>\n<p>&nbsp;<\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Valve Radio Mains Transformer Ok\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/pXkMYWLpl7M?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Radio DC Rectifier Valve OK\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/hO-5jP8ymiQ?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>I will use my dim bulb tester for the next tests. If you do the power calculations, you will understand why a lower wattage INCANDESCENT (AC resistive\/reactive) bulb limits the current to the device under test in the event of a short circuit in the unit, so also limits the voltage applied to the unit to hopefully not overstress old capacitors too much while they may be reforming to a temporary working state:<\/p>\n<p>P = IV<\/p>\n<p><strong>25W incandescent bulb:<\/strong><\/p>\n<p>25W\/ 240V = <strong>104 mA<\/strong><\/p>\n<p><strong>40W incandescent bulb:<\/strong><\/p>\n<p>40W\/ 240V = <strong>167 mA<\/strong><\/p>\n<p><strong>100W incandescent bulb:<\/strong><\/p>\n<p>100W\/ 240V = <strong>416 mA mA<\/strong><\/p>\n<p><strong>150W incandescent bulb:<\/strong><\/p>\n<p>150W\/240 = <strong>0.625 mA <\/strong><\/p>\n<p>https:\/\/www.youtube.com\/watch?v=pqTFaK0G5-c<\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Valve Radio Dim Bulb Tests\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/dUCPEBfkAAo?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Chanson MW Station Found\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/lnBiBzEaJaI?start=1&feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Radio, BBC 4 MW via TV aerial socket\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/GzS9XwavNEk?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Valve Radio faint, foreign SW stations found with different aerial.\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/PDyZ4FSsxso?start=20&feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><iframe loading=\"lazy\" title=\"Vidor Valve Radio Finished.\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/8tZuJg2cAfM?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><iframe loading=\"lazy\" title=\"Chat to Emphasise Valve Amp discharge and electrical safety.\" width=\"1778\" height=\"1000\" src=\"https:\/\/www.youtube.com\/embed\/3tnKYhKienk?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p>Short Wave ranging from 200-600 meters, and the wavelength of the HF is 10 to 100 meters.<\/p>\n<p>Medium Wave, also known as intermediate frequency (MF), that is, radio waves with a frequency of 300KHz-3MHz.<\/p>\n<p>Long Wave, between 150KHz-284KHz as the broadcast spectrum is used, the wavelength is concerned, it is about 1000 to 2000 meters.<\/p>\n<p><a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/FreqTable.webp\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-9917\" src=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/FreqTable.webp\" alt=\"\" width=\"768\" height=\"592\" srcset=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/FreqTable.webp 768w, https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-content\/uploads\/2022\/12\/FreqTable-300x231.webp 300w\" sizes=\"auto, (max-width: 768px) 100vw, 768px\" \/><\/a><\/p>\n<p><img decoding=\"async\" src=\"https:\/\/terasense.com\/wp-content\/uploads\/2019\/04\/radio-frequency-bands.png\" alt=\"Radio frequency bands\" \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This old radio was \u00a320 but good condition in a dog charity store. It has a full valve compliment so seemed worth the risk. I don't have much test gear these days, so did what checks I could with what I have and no oscilloscope. I decided to go ahead and do what I can <a href=\"https:\/\/stevepedwards.today\/ElectronicsStuff\/1946-vidor-chanson-cn349-valve-radio-checks\/\" class=\"more-link\">...<span class=\"screen-reader-text\">  1946 Vidor Chanson CN349 Valve Radio Checks<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-9883","post","type-post","status-publish","format-standard","hentry","category-tech-studies"],"_links":{"self":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9883","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/comments?post=9883"}],"version-history":[{"count":41,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9883\/revisions"}],"predecessor-version":[{"id":9929,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/posts\/9883\/revisions\/9929"}],"wp:attachment":[{"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/media?parent=9883"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/categories?post=9883"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/stevepedwards.today\/ElectronicsStuff\/wp-json\/wp\/v2\/tags?post=9883"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}