{"id":851,"date":"2020-01-08T07:47:15","date_gmt":"2020-01-07T21:17:15","guid":{"rendered":"http:\/\/parablog-wordpress.dockerbox.rei.moe\/?p=851"},"modified":"2020-01-10T06:32:26","modified_gmt":"2020-01-09T20:02:26","slug":"designing-an-even-cheaper-isolated-digital-interface-for-amateur-radios","status":"publish","type":"post","link":"https:\/\/blog.lewys.eu\/?p=851","title":{"rendered":"Designing an even cheaper isolated digital interface for amateur radios"},"content":{"rendered":"\n

A few months ago, the ACMA made changes to the amateur LCD that allowed foundation class licensees to operate digital modes. <\/a><\/p>\n\n\n\n

Excited to get into this in the new year, I begun looking into digital interfaces for the radios I already have. There’s many different ways this can be done, from as simple as not using a cable and relying on microphones and speakers, creating a straight through cable from the PC mic input to the radio speaker output and visa versa, to expensive isolated interface boards custom made in the USA. <\/p>\n\n\n\n

I wanted an isolated board, because I have enough trouble with interference and noise in my apartment already, so the first two were out (although I did make a straight through cable for my Baofeng UV-5R for SSTV on 2m\/70cm). <\/p>\n\n\n\n

So I turned to the expensive isolated interfaces. <\/p>\n\n\n\n

There’s plenty to choose from l, with different feature levels and prices! From the $230USD RigBlaster<\/a>, the $200AUD SignalLink USB<\/a>, and even the cheapest of the bunch, the Easy-Digi<\/a> coming in at $30-50AUD shipped with slow shipping…<\/p>\n\n\n\n

Naturally being a cheap ass I wasn’t overly satisfied with these options..<\/p>\n\n\n\n

Luckily though, the Easy-Digi, saved the day! It’s such a simple design, with a published schematic<\/a>, that it’s not too hard to roll your own with a few changes!<\/p>\n\n\n\n

I jumped into EasyEDA<\/a> and learnt how to do a basic schematic, then designed the interface circuit for audio using two 600:600ohm isolation transformers, and a PTT circuit using a DB9 rs232 connector because it’s easy, although I plan to replace that with a USB-C connector and a ch340 rs232 IC in a later revision!<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

I used components that I either already have laying around, or can get easily from JayCar for the most part. <\/p>\n\n\n\n

The connectors and transformers I ordered from China at about $4-5 for 10pcs each. <\/p>\n\n\n\n

With the layout done, I generated a PCB, and moved components around into a rough layout I was happy with, and hit the autoroute button :^)<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
\"\"<\/figure>\n\n\n\n

I forgot to label the PC side connectors for the first revision, but I imagine there will be plenty of other changes I make anyway. <\/p>\n\n\n\n

I uploaded the gerbers to JLCPCB to produce a test run of the PCB, which I should have within 2 weeks with the cheap shipping :^)<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

So if everything goes according to plan, I cluding parts and PCB manufacturing for 10 boards, I’ll have spend about $30-35 total, and I should be able to sell some of the boards to friends for $5-10 each offsetting my costs even more !<\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

A few months ago, the ACMA made changes to the amateur LCD that allowed foundation class licensees to operate digital modes. Excited to get into this in the new year, I begun looking into digital interfaces for the radios I already have. There’s many different ways this can be done, from as simple as not … Continue reading Designing an even cheaper isolated digital interface for amateur radios<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":852,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28,34,18,25],"tags":[],"class_list":["post-851","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-amateur-radio","category-electronics-gore","category-projects","category-wireless"],"jetpack_featured_media_url":"https:\/\/blog.lewys.eu\/wp-content\/uploads\/2020\/01\/Screenshot_20200108-075920_Chrome.jpg","_links":{"self":[{"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/posts\/851","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=851"}],"version-history":[{"count":1,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/posts\/851\/revisions"}],"predecessor-version":[{"id":853,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/posts\/851\/revisions\/853"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=\/wp\/v2\/media\/852"}],"wp:attachment":[{"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=851"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=851"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.lewys.eu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=851"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}