\nPSK31 on the 20m band operates on USB. The dial frequency is 14.070 MHz.<\/p>\n
The shack transceiver was tuned to 14.070 MHz. The tip of a short coax cable, from it’s antenna socket, was held close to the PSK31 board’s local oscillator circuit. Key devices here are IC1 and Xtal CR3, \u00a0shown in the photo and circuit diagram below. The frequency of the 14MHz local oscillator on the PSK31 board was adjusted\u00a0with C11. The aim here was to make the\u00a0transceiver’s audio tone\u00a0 drop in frequency, toward zero Hertz. As the audio tone approaches zero Hertz it will no longer be heard.\u00a0This ‘zero-beat’\u00a0 frequency confirmed that the PSK31 board oscillator matched the 14.070 MHz displayed on the transceiver.<\/p>\n <\/p>\n PSK31 Digital Mode Software<\/strong><\/em> [Screen captured in MM0PYR shack on 10 April 2014]<\/p>\n The strong signals received were error free. Some of the weaker stations however contained errors in the message received. This is likely due to the lower signal to noise ratio for weaker stations. Further testing in better conditions on the 20m band are required to confirm this.<\/p>\n Stations Received<\/strong><\/em> Well done MM6LKG (Arthur), for getting the RSGB PSK31 Centenary receiver built and working, completing this project for the Intermediate License practical assesment.<\/p>\n What Next<\/strong><\/em> Digital Mode Software<\/strong><\/em> www.digipan.net<\/a> <\/p>\n","protected":false},"excerpt":{"rendered":" With the 2n3819 JFET fitted, it was time to test the receiver once again. Final Tuning PSK31 on the 20m band operates on USB. The dial frequency is 14.070 MHz. The shack transceiver was tuned to 14.070 MHz. The tip of a short coax cable, from it’s antenna socket, was held close to the PSK31\u2026 Read More »<\/a><\/span><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[9],"tags":[],"_links":{"self":[{"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=\/wp\/v2\/posts\/183"}],"collection":[{"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=183"}],"version-history":[{"count":83,"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=\/wp\/v2\/posts\/183\/revisions"}],"predecessor-version":[{"id":277,"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=\/wp\/v2\/posts\/183\/revisions\/277"}],"wp:attachment":[{"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=183"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=183"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/elderslie-ars.org.uk\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=183"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Local](\"http:\/\/elderslie-ars.org.uk\/wp-content\/uploads\/2014\/04\/Local-Oscillator-IC1-CR3-C11.png\")
<\/a>A low\u00a0frequency audio tone was heard from the shack tranceiver.<\/p>\n<\/a>With tuning complete the shack antenna was connected to the PSK31 board coax cable and SO239 plug. The audio cable was connected between the board’s 3.5mm jack-socket, SK1,\u00a0 and the computer mic input.<\/p>\n
\nThe DIGIPAN software was already installed on the shack Windows PC. However some settings required adjustment. With the mode set to BPSK31 and Receive ( RX)\u00a0 selected, the computer mic volume was lowered to reduce the noise on the DIGIPAN screen ( Yellow colour). With a lower audio input level the display\u00a0 produced a mosty blue background. Now the BPSK31 signals were clearly visible as yellow vertical lines (see screen shot below)<\/p>\n<\/a><\/p>\n
\nFrom the DIGIPAN screen-shot it can be seen that received stations included YU7AS in Serbia,\u00a0 distance 2,000 km (1,300\u00a0 miles) , OE1TRB in Austria, 1,600km (1,000 miles) and DG0DE , Germany, 1,400km (860 miles).<\/p>\n
\nNow that the board is complete and working it only remains to tidy the project up. Fitting the board, battery, power switch and antenna connector into a suitable enclosure will make it more\u00a0robust for use in the shack.<\/p>\n
\nTwo of the software packages available for digital mode PSK31 include DIGIPAN and FLDIGI. These can be downloaded from the sites below. There are others.<\/p>\n
\nw1hkj.com\/Fldigi.html<\/a><\/p>\n