{"id":3453,"date":"2016-09-26T12:41:26","date_gmt":"2016-09-26T11:41:26","guid":{"rendered":"http:\/\/lefars.org.uk\/WPblog\/?p=3453"},"modified":"2016-10-15T17:02:04","modified_gmt":"2016-10-15T16:02:04","slug":"raspberry-pi-zero-used-as-a-30-metre-wspr-transmitter","status":"publish","type":"post","link":"https:\/\/lefars.org.uk\/WPblog\/raspberry-pi-zero-used-as-a-30-metre-wspr-transmitter\/","title":{"rendered":"Raspberry pi Zero used as a 30 metre Wspr Transmitter"},"content":{"rendered":"

I have assembled a 30 metre low-pass filter from Language Spy (link here)<\/a> and soldered header pins to the GPIO on the Raspberry Pi zero<\/a>.
\nNote that the Pi-LPF kit uses surface-mount components and provides a 7-pole Chebyshev low-pass filter for harmonic suppression.<\/p>\n

WsprryPi<\/a> was loaded onto the micro sd card. The RF output is 10mW, time will tell how far I will get. 30 metres was very busy at the time of testing with a contest .\u00a0Tested over the weekend, it ran for 8 hours on a quarter-charged 10,000 mAh battery .
\nFrom the WsprrPi application notes:-<\/p>\n

“….As the Raspberry Pi does not attenuate ripple and noise components from the\u00a05V USB power supply, it is RECOMMENDED to use a regulated supply that has\u00a0sufficient ripple suppression. Supply ripple might be seen as mixing products\u00a0\u00a0centered around the transmit carrier typically at 100\/120Hz.”<\/p><\/blockquote>\n

I am using M0CVO\u2019s HW-42HP Off Centre Fed Dipole antenna in the loft, link here<\/a> \u00a0.<\/p>\n

Pictures below.<\/p>\n

73<\/p>\n

Derek M0XDC
\nEmail: m0xdc@lefars.org.uk<\/a><\/p>\n

P.S. 20m and 40m filters now also assembled. Map and 40m log below. \u00a0Updated 30m map and log. Also comparison with all three filters…
\n
\n\"image002\"<\/a>
\n\"image001\"<\/a><\/p>\n

 <\/p>\n

 <\/p>\n

Update 15th October 2016 – 20m filter board<\/strong>
\n<\/a>The 20m filter board has been built. \u00a0Shown below mounted on the Raspberry Pi Zero. Note that the USB cable connects the Wi-Fi dongle.<\/p>\n

\"20m<\/a>

20m filter on Rpi Zero, 40m top right, 30m bottom right<\/p><\/div>\n

\"With<\/a>

With 20m filter<\/p><\/div>\n

\"Without<\/a>

Without 20m filter<\/p><\/div>\n

 <\/p>\n

Update 6th October 2016 – 30m WSPR map and log<\/strong>
\n\"30mwsprmap\"<\/a>\"30mwsprlog\"<\/a><\/p>\n

 <\/p>\n

Update 1st October 2016 – 40m filter board<\/strong>
\nThe 40m filter board has been built. 10mW (+10dBm) on 7.040MHz from M0XDC was heard by DF5FH 649km away. Map and 40m log below.
\n\"m0xdc_40m_wspr_log\"<\/a>
\n\"m0xdc_40mwspr_map\"<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

I have assembled a 30 metre low-pass filter from Language Spy (link here) and soldered header pins to the GPIO on the Raspberry Pi zero. Note that the Pi-LPF kit uses surface-mount components and provides a 7-pole Chebyshev low-pass filter … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"gallery","meta":{"_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":""},"categories":[10,67],"tags":[],"class_list":["post-3453","post","type-post","status-publish","format-gallery","hentry","category-home-construction","category-raspberry-pi","post_format-post-format-gallery"],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p22sia-TH","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/posts\/3453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/comments?post=3453"}],"version-history":[{"count":21,"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/posts\/3453\/revisions"}],"predecessor-version":[{"id":3490,"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/posts\/3453\/revisions\/3490"}],"wp:attachment":[{"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/media?parent=3453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/categories?post=3453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lefars.org.uk\/WPblog\/wp-json\/wp\/v2\/tags?post=3453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}