{"id":13316,"date":"2015-05-22T07:38:53","date_gmt":"2015-05-22T11:38:53","guid":{"rendered":"http:\/\/swling.com\/blog\/?p=13316"},"modified":"2015-05-23T07:34:54","modified_gmt":"2015-05-23T11:34:54","slug":"how-to-replace-a-noisy-wall-power-supply","status":"publish","type":"post","link":"https:\/\/swling.com\/blog\/2015\/05\/how-to-replace-a-noisy-wall-power-supply\/","title":{"rendered":"How to replace a noisy wall power supply"},"content":{"rendered":"

\"JamecoWallPowerSupply\"<\/a>Regarding noisy switching power supplies<\/a>, SWLing Post<\/em> reader, Dan Lewis<\/a>, comments:<\/p>\n

“Google the following: \u201cJameco linear wall transformer\u201d, and you\u2019ll find a suitable non-switching replacement.<\/p>\n

Jameco still has a number of linear transformers in their catalog at reasonable prices. I haven\u2019t bought anything from them in many years but when I dealt with them frequently a number of years back they were always reputable.”<\/p><\/blockquote>\n

Many thanks for your suggestion, Dan!\u00a0Jameco is a reliable company and I’ve also been a long-time customer. If you know how to pick the proper power supply for your radio (or any other electronic device) click here to view a list of regulated linear supplies on Jameco’s website<\/a>. [Also note this follow-up post.<\/a>]Otherwise, keep reading…<\/p>\n

How to find a replacement AC adapter\/power supply<\/h2>\n

When\u00a0you purchase a replacement power supply, you must make sure that several properties match that of the device it will power, else you could cause damage.<\/p>\n

There are four properties you need to match: voltage, rated current, polarity and tip size.<\/p>\n

Voltage<\/strong><\/p>\n

Most consumer electronics are powered by and rated for 4.5, 5, 9, 12, or 13.8 volts DC. Of course, there are exceptions. It is important that you\u00a0match the required voltage exactly. Most radios and electronic devices display their required voltage and voltage tolerance on the unit itself, on the supplied switching power supply, and\/or in the owner’s manual.<\/p>\n

Rated Current<\/strong><\/p>\n

Like voltage, rated current is usually displayed somewhere on the device, existing power supply or in the owner’s manual. Current is usually indicated in amps (A) or milliamps (mA). Unlike voltage, rated current on your power supply does not have to match the device exactly. You simply need to make sure the power supply meets or exceeds<\/em><\/strong> your radio’s required current.<\/p>\n

For example, if your radio requires 800 mA (or .8 A) and you find a power supply rated for 500 mA, you should not<\/em> use it. If you find a power supply rated for 2 amps (or 2000 mA), it exceeds the 800 mA rating, so you’re good to go!<\/p>\n

Unlike voltage, your electronic device or radio will only draw the amount of current it needs from the power supply.<\/p>\n

Polarity<\/strong><\/p>\n

\"Click<\/a>

Click here to read more about tip polarity. (Source: WikiPedia)<\/p><\/div>\n

You’ll need to determine if your radio requires a plug with a positive or negative tip (a.k.a. center conductor).<\/p>\n

Fortunately, manufacturers have long used standard symbols to make polarity obvious (see image).<\/p>\n

You’ll typically find a polarity symbol printed on the back of your radio, near the plug-in point, in the owner’s manual or on the back of the existing\u00a0wall adapter.<\/p>\n

Note: Be very<\/em> careful matching polarity!<\/strong> Some radios and electronic devices are not properly protected against reverse polarity; damaged can occur immediately after supplying voltage with incorrect polarity.<\/p>\n

T\"JamecoWallPowerSupply\"<\/a>ip\/plug size<\/strong><\/p>\n

You need to make sure that the inner diameter and outer diameter of a replacement wall adapter will match that of your existing adapter.<\/p>\n

This can be\u00a0the most difficult property to match.<\/p>\n

Occasionally, radio manufacturers will actually specify the tip size in their owner’s manual, spec sheets, or on the product page of their website. I’ve even had luck calling manufacturers and asking a technician for the plug size.<\/p>\n

\"ACAdapterTip\"<\/a>

Specification sheets will typically indicate plug dimensions with an illustration.<\/p><\/div>\n

Otherwise,\u00a0you can always measure the existing power supply tip (both inner and outer dimensions) using calipers.<\/p>\n

Once you have those dimensions, finding the appropriate replacement power\u00a0supply is quite easy. Indeed, companies like Jameco<\/a> provide specification sheets (click here for an example<\/a>) that indicate dimensions for each power supply\u00a0they sell.<\/p>\n

Once you’ve\u00a0matched the voltage, rated current, polarity and tip size<\/strong>, you can purchase a regulated linear power supply with confidence<\/a>!<\/p>\n

Keep in mind: there are most likely\u00a0other devices in your home with noisy switching power supplies that could be causing radio interference.\u00a0Check out my noise trouble shooting section of this article to help identify local sources of radio noise<\/a>.<\/p>\n

Update:<\/strong> check out this follow-up post regarding Jameco power supplies–not all are truly linear regulated.<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Regarding noisy switching power supplies, SWLing Post reader, Dan Lewis, comments: “Google the following: \u201cJameco linear wall transformer\u201d, and you\u2019ll find a suitable non-switching replacement. Jameco still has a number of linear transformers in their catalog at reasonable prices. I haven\u2019t bought anything from them in many years but when I dealt with them frequently […]<\/p>\n","protected":false},"author":15,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[373,8,627,3,3196,26,43,1113],"tags":[3845,1260,4105,3847,4089,197,3846,453,3841,3848],"class_list":["post-13316","post","type-post","status-publish","format-standard","hentry","category-am","category-articles","category-how-to","category-news","category-portable-radio","category-radios","category-shortwave-radio","category-tutorials","tag-ac-adapters","tag-dan-lewis","tag-how-to","tag-jameco","tag-qrm","tag-radio-interference","tag-regulated-power-supply","tag-rfi","tag-switching-power-supply-noise","tag-tutorial"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/pn3uc-3sM","jetpack-related-posts":[{"id":13325,"url":"https:\/\/swling.com\/blog\/2015\/05\/dave-says-not-all-jameco-power-supplies-are-linear-and-regulated\/","url_meta":{"origin":13316,"position":0},"title":"Dave says not all Jameco power supplies are linear and regulated","author":"Thomas","date":"May 23, 2015","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dave Zantow (N9EWO), who replies to a post published yesterday regarding some of Jameco linear power supplies. Dave writes: \"A bit of a caveat on Jameco\u2019s these so called Linear power supplies. This is based from my own experiences so is not fiction. Bottom\u2026","rel":"","context":"In "Articles"","block_context":{"text":"Articles","link":"https:\/\/swling.com\/blog\/category\/articles\/"},"img":{"alt_text":"Note that not all power supplies are listed as \"regulated linear\"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=525%2C300 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/05\/JamecoPowerSupplies.jpg?resize=700%2C400 2x"},"classes":[]},{"id":21923,"url":"https:\/\/swling.com\/blog\/2016\/10\/daves-review-of-the-mfj-10261025-and-regulated-ac-adapter-recommendations\/","url_meta":{"origin":13316,"position":1},"title":"Dave’s review of the MFJ-1026\/1025 and regulated AC adapter recommendations","author":"Thomas","date":"October 26, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dave Zantow (N9EWO), who shares the following reply to TomL's post More Anti-Noise Ideas: My VERY NOISY Sony CRT TV has gone to the great electronics recycling bin in the sky thank goodness. But I still have a MFJ-1026 here and need to use\u2026","rel":"","context":"In "Accessories"","block_context":{"text":"Accessories","link":"https:\/\/swling.com\/blog\/category\/accessories\/"},"img":{"alt_text":"mfj-1026","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/10\/mfj-1026.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/10\/mfj-1026.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/10\/mfj-1026.jpg?resize=525%2C300 1.5x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/10\/mfj-1026.jpg?resize=700%2C400 2x"},"classes":[]},{"id":48268,"url":"https:\/\/swling.com\/blog\/2021\/03\/jack-finds-that-chokes-have-a-huge-impact-on-switching-power-supply-noise\/","url_meta":{"origin":13316,"position":2},"title":"Jack finds that chokes have a huge impact on switching power supply noise","author":"Thomas","date":"March 28, 2021","format":false,"excerpt":"Many thanks to SWLing Post contributor, Jack Dully, who writes: I was putting some things in my radio junk parts box and came across some chokes. So I tried a test with my Tecsun PL-880 on battery and the Tecsun supplied switching AC adapter, with and without chokes on the\u2026","rel":"","context":"In "Ham Radio"","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/05\/PowerAdaptor.jpg?resize=350%2C200&ssl=1","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/05\/PowerAdaptor.jpg?resize=350%2C200&ssl=1 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/05\/PowerAdaptor.jpg?resize=525%2C300&ssl=1 1.5x"},"classes":[]},{"id":13304,"url":"https:\/\/swling.com\/blog\/2015\/05\/sangean-blames-am-interference-on-power-supply-and-government-regulation\/","url_meta":{"origin":13316,"position":3},"title":"Sangean blames AM interference on power supply and government regulation","author":"Thomas","date":"May 20, 2015","format":false,"excerpt":"After the Sangean WR-15 received low marks for AM reception in an Amazon review, Bob of Sangean America\u00a0replied that\u00a0poor reception is due to the radio's switching power supply--a design that is federally mandated. Many thanks to Jeff over at the Herculodge for posting this (click here to read the full\u2026","rel":"","context":"In "AM"","block_context":{"text":"AM","link":"https:\/\/swling.com\/blog\/category\/am\/"},"img":{"alt_text":"Sangean-AMFM-Radio","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2015\/03\/Sangean-AMFM-Radio.jpg?resize=350%2C200","width":350,"height":200},"classes":[]},{"id":22675,"url":"https:\/\/swling.com\/blog\/2016\/12\/chris-tracks-down-sources-of-radio-noise\/","url_meta":{"origin":13316,"position":4},"title":"Chris tracks down sources of radio noise","author":"Thomas","date":"December 6, 2016","format":false,"excerpt":"Many thanks to SWLing Post contributor, Chris Smolinski, who shares this guest post from his blog, RadioHobbyist.org: Yet Another !&*%$! Noise Source by Chris Smolinski The past few days, I have noticed higher than usual noise levels, generally on the lower frequencies, and particularly on the longwave band, including the\u2026","rel":"","context":"In "Ham Radio"","block_context":{"text":"Ham Radio","link":"https:\/\/swling.com\/blog\/category\/ham-radio\/"},"img":{"alt_text":"spectrum-waterfall-sdr","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Spectrum-Waterfall-SDR.jpg?resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Spectrum-Waterfall-SDR.jpg?resize=350%2C200 1x, https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2016\/12\/Spectrum-Waterfall-SDR.jpg?resize=525%2C300 1.5x"},"classes":[]},{"id":12031,"url":"https:\/\/swling.com\/blog\/2015\/01\/c-crane-cc-witness-usb-ac-adapter-on-sale\/","url_meta":{"origin":13316,"position":5},"title":"C.Crane CC Witness USB AC Adapter on sale","author":"Thomas","date":"January 23, 2015","format":false,"excerpt":"Many thanks to SWLing Post contributor, Dave Zantow (N9EWO) who writes: I see that CCrane Witness USB AC Adapter is on sale for $9.95 right now. This analog regulated supply (as reviewed on my web page) works very well with other 5 volt mini-USB powered sets for MW\/SW RADIO use\u2026","rel":"","context":"In "News"","block_context":{"text":"News","link":"https:\/\/swling.com\/blog\/category\/news\/"},"img":{"alt_text":"CCraneACAdaptor","src":"https:\/\/i0.wp.com\/swling.com\/blog\/wp-content\/uploads\/2014\/11\/CCraneACAdaptor.jpg?resize=350%2C200","width":350,"height":200},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/13316","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/users\/15"}],"replies":[{"embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/comments?post=13316"}],"version-history":[{"count":0,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/posts\/13316\/revisions"}],"wp:attachment":[{"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/media?parent=13316"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/categories?post=13316"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/swling.com\/blog\/wp-json\/wp\/v2\/tags?post=13316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}