{"id":27311,"date":"2011-09-28T17:26:10","date_gmt":"2011-09-28T16:26:10","guid":{"rendered":"http:\/\/www.cqdx.ru\/ham\/?p=27311"},"modified":"2023-10-11T11:28:33","modified_gmt":"2023-10-11T09:28:33","slug":"the-njqrp-psk31-audio-beacon-kit","status":"publish","type":"post","link":"https:\/\/www.cqdx.ru\/ham\/qro-qrp\/the-njqrp-psk31-audio-beacon-kit\/","title":{"rendered":"The NJQRP PSK31 Audio Beacon Kit"},"content":{"rendered":"

(The PSK31 Audio Beacon was a feature technical article in the August 2001 issue of QST<\/a>)<\/strong><\/em><\/span>
\nFILES:\u00a0 Schematic<\/a> | Source Code<\/a> | Parts Layout<\/a>
\nDOC:\u00a0 Technical Manual v2.0<\/a>\u00a0\u00a0 (540 KB PDF file)
\nKit Notes Page:\u00a0 Check here for errata<\/a>
\nKIT STATUS: In Stock<\/span><\/strong><\/span>
\nKIT ORDERING:\u00a0 Click here<\/a><\/span><\/strong><\/p>\n

\"\"<\/a><\/p>\n

KIT DESCRIPTION<\/span><\/span><\/p>\n

Here\u2019s an easy, fun and intriguingly useful project that has evolved from an ongoing design effort to reduce the complexity of a PSK31 controller.\u00a0 <\/span><\/span><\/p>\n

A conventional PC typically provides the relatively intensive computing power required for PSK31 modulation and demodulation.\u00a0 With this Beacon<\/span> project, however, the PSK31 modulation computations have been designed to fit into a small PIC-like microcontroller that can serve as the basis for the transmit half of a standalone PSK31 controller. <\/span><\/span><\/p>\n

A fast and inexpensive\u00a0 microcontroller has been programmed to generate an audio data stream using the PSK31 algorithms.\u00a0 The data-driven audio waveform is fed to an amplifier IC that drives a speaker – and voila<\/em>, the familiar and melodious PSK31 warble is able to be heard! When presented as input to a PSK31 receiving system such as DigiPan, these modulated audio tones are decoded and the programmed beacon string is displayed. <\/span><\/span><\/p>\n

A keyboard or data terminal may also serve as the input of real-time textual data to the PSK31 Audio Beacon. A standard RS-232 serial interface is provided in the hardware and software to allow a more dynamic \u201csignal generator\u201d use of the project.\u00a0 <\/span><\/span><\/p>\n

The project can be electrically connected to the input of an SSB transmitter to create an RF PSK31 beacon.<\/span><\/span><\/p>\n

This project is also ideally suited for groups wishing to have some \u201caudio beacon\u201d fun during meetings. A number of club members would operate their audio beacons while someone attempts successful copy of the beacon strings while sitting at a laptop equipped with DigiPan software.<\/span><\/span><\/p>\n

Construction is simple and straightforward and you\u2019ll have immediate feedback on how your Beacon works when you plug in a 9V battery and speaker.<\/span><\/span><\/p>\n

THE “BEACON” PART<\/span><\/span>
\nThe “beacon” part of the kit comes about in the kind of data programmed into the PIC.\u00a0 Each kit’s microcontroller comes pre-programmed with a simple informational string containing (at a minimum) the individual’s callsign and a code word. (Use of a code words is typical for beacon transmitters).\u00a0 For example, the data string currently programmed in my PSK31 Beacon is an endless loop of:<\/span><\/p>\n

<idle stream of 60 zeros> …. PSK31 Beacon de N2APB\/B code 8926 n2apb@amsat.org\u00a0<\/span><\/p>\n

Further, in order to provide additional distinction in the signal, one is able to configure use of one of three carrier base frequencies (500 Hz, 1 KHz or 2 KHz), as well being able to configure use of 16 minor variations in frequency around the carrier base frequency..\u00a0 (More on these last two aspects in a bit.)<\/span><\/span><\/p>\n

“SO, WHAT CAN ONE DO WITH AN AUDIO PSK31 BEACON?”<\/span><\/span>
\nAs mentioned, the Beacon may be used as the basis for a fun group \u201ccontest\u201d activity for your club. All contestants would turn their beacons on and gather around a laptop running the DigiPan application.\u00a0 Laptops generally have built-in microphones that would be used to decode the audio PSK31 tones “in the air” … and with over 100 beacons warbling simultaneously, there will certainly be audio tones in the air! <\/span><\/p>\n

Recall that each Beacon’s microcontroller is customized with a callsign and is run on slightly different frequencies.\u00a0 One Beacon may have its tones centered at 978 Hz, while another may have it’s tones at 1050 Hz.\u00a0 This spreading out of Beacon signals will help when multiple beacons are placed in service at the same time within close geographic proximity. <\/span><\/p>\n

Okay, so you’ve got the picture of a whole bunch of club members amassed around a table with an operator sitting at the laptop running DigiPan, right?\u00a0 Within a specified period of time, the idea is to see how many of the Beacons can be copied (callsign & code word), as captured by DigiPan.\u00a0 Factors involved in successful reception include the settings of the audio amp, the type of speaker, the distance between the Beacon and the laptop, adjacent QRM (other Beaconers), etc. “Points” are awarded to all Beacons for the degree of solid copy captured to the DigiPan log during that 15 minute period.\u00a0 (You can see a photo of this excitement in June QST\u2019s \u201cQRP Power\u201d column on page ___, as snapped by Rich Arland K7SZ at the Atlanticon QRP Forum held this past springtime.)<\/em> <\/span><\/p>\n

This all may may sound complex, but it’s really quite simple — build the Beacon, turn it on and see how well it can be copied by DigiPan.\u00a0 Each contestant could actually do this during the test phase at home prior to the club event.<\/span><\/span><\/p>\n

USING THE BEACON<\/span><\/span>
\nSure, projects can be fun for a weekend’s contest or fun activity, but the PSK31 Audio Beacon can have lasting value for the PSK31 enthusiast.\u00a0 The audio tones generated by the Beacon can be presented as input to any SSB transmitter — a Warbler, PSK-20, PSK-40, or even a Yaesu FT-1000MP.\u00a0 Thus, a PSKer can easily put a beacon signal on the air for all the same reasons that CW beacons are used (e.g., propagation studies, etc.)<\/span><\/p>\n

Recall that each Beacon’s microcontroller is customized with one’s callsign and is run on slightly different frequencies.\u00a0 One Beacon may have its tones centered at 978 Hz, while another may have it’s tones at 1050 Hz.\u00a0 This spreading out of Beacon signals will help when multiple beacons are placed in service at the same time within close geographic proximity.<\/p>\n

PRICE<\/span><\/span>
\nThis kit is no longer available.<\/p>\n","protected":false},"excerpt":{"rendered":"

(The PSK31 Audio Beacon was a feature technical article in the August 2001 issue of QST) FILES:\u00a0 Schematic | Source Code | Parts Layout DOC:\u00a0 Technical Manual v2.0\u00a0\u00a0 (540 KB PDF file) Kit Notes Page:\u00a0 Check here for errata KIT STATUS: In Stock KIT ORDERING:\u00a0 Click here KIT DESCRIPTION Here\u2019s an easy, fun and intriguingly…<\/p>\n","protected":false},"author":2,"featured_media":27313,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[10],"tags":[259],"class_list":["post-27311","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-qro-qrp","tag-kit","category-10","description-off"],"_links":{"self":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/posts\/27311","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/comments?post=27311"}],"version-history":[{"count":0,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/posts\/27311\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/media\/27313"}],"wp:attachment":[{"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/media?parent=27311"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/categories?post=27311"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cqdx.ru\/ham\/wp-json\/wp\/v2\/tags?post=27311"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}