{"id":2426,"date":"2023-03-24T14:20:00","date_gmt":"2023-03-24T03:20:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2023\/03\/24\/homebrew-am-from-cuba\/"},"modified":"2025-07-22T18:02:25","modified_gmt":"2025-07-22T08:02:25","slug":"homebrew-am-from-cuba","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2023\/03\/24\/homebrew-am-from-cuba\/","title":{"rendered":"Homebrew AM from Cuba"},"content":{"rendered":"<\/p>\n
<\/a><\/div>\n

Jose CO6EC sent us more information about homebrew rigs built in Cuba. The transmitter above is a thing of beauty. I am really glad that Jose has held on to it. Thanks Jose! <\/b><\/i><\/p>\n

<\/a><\/div>\n
Jose CO6EC today<\/div>\n

Jose CO6EC writes: <\/b><\/span><\/p>\n<\/p>\n

This is another work from that time: an AM and CW transmitter of about 100W of power, with an on-board modulator. <\/span>It was taken with some modifications from a Handbook from the 50s. Here goes: <\/span><\/span> <\/span>it was built with what we had on hand at that time, it still exists, I keep it as a relic of those years.<\/span><\/span><\/b><\/span><\/p>\n

It u<\/span>sed combined Soviet and American tubes in the RF sections: Soviet 6P9 and (2) 6146. <\/span><\/span> The m<\/span>odulator used Soviet 12AX7, 12AUT and (2) 6P7. <\/span>The 6P9 works as a crystal oscillator, and in <\/span><\/span> <\/span>case of using an external VFO it works as an amplifier and doubler or tripler to obtain outputs in <\/span><\/span>the 160,80,40,20,15 and 10 Meter bands. <\/span><\/span><\/b><\/span><\/span><\/p>\n

The VFO was also taken from a <\/span><\/span>1949 Handbook if I remember correctly, but I don’t have any literature on that, as you can see in the photo it has 5 5u4c rectifier valves, VR150 voltage stabilizer, 6v6 output, another 6v6 as a separator and a 6 )I(4 (60I94?) Soviet, in the oscillator. The stability they achieved in those years is incredible, <\/span><\/span> <\/span>I could communicate with stations that were on LSB and if I didn’t tell them that I was on AM they didn’t notice. <\/span><\/span><\/b><\/span><\/p>\n

<\/span>As a receiver I used an old <\/span><\/span> <\/span>Soviet AM and CW receiver, used by the Aviation HF stations <\/span><\/span> <\/span>of the 40s, which no longer exists hihihihihi<\/span><\/span><\/span><\/b><\/span><\/span><\/p>\n

I’ll tell you how I tuned all that good ftuff: F<\/span><\/span>irst I put the receiver <\/span><\/span> <\/span>in CW to beat the signal of the stations in SSB. After hearing them clearly, I removed the oscillator of the receiver <\/span><\/span> <\/span>and connected only the VFO of the Transmitter, and beat the <\/span>signal <\/span><\/span>with that o<\/span><\/span>f the r<\/span><\/span>eceiver until I heard the other station clearly, then I put the transmitter to work and was ready to communicate.<\/span><\/span><\/span><\/b><\/span><\/span><\/p>\n

There were many communications made with that station, even internationally <\/span><\/span>on phone <\/span><\/span> <\/span>and CW. <\/span><\/span><\/span><\/b><\/span><\/span><\/p>\n

Today everything is easier because with transceivers it is not necessary to go through all that work, <\/span><\/span>but it is always good that those who did all this work know how r<\/span><\/span>adio was built and made.<\/span><\/span><\/span><\/b><\/span><\/span><\/p>\n

<\/span>73 <\/span><\/span> <\/span>Jose CO6EC<\/span><\/span><\/b><\/span><\/span><\/p>\n

<\/span><\/span><\/p>\n

<\/a><\/span><\/div>\n
Obviously the transmitter<\/span><\/div>\n

<\/p>\n

<\/a><\/div>\n
<\/a><\/div>\n
The two pictures above must be the VFO. It looks like the VFO in the 1947 ARRL Handbook. <\/div>\n

<\/p>\n

<\/a><\/div>\n
I wonder what handbook this was? Spanish language. <\/div>\n


<\/span><\/span><\/p>\n


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

Jose CO6EC sent us more information about homebrew rigs built in Cuba. The transmitter above is a thing of beauty. I am really glad that Jose has held on to it. Thanks Jose! Jose CO6EC today Jose CO6EC writes: This is another work from that time: an AM and CW transmitter of about 100W of … Continue reading “Homebrew AM from Cuba”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":2427,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[130,302,275],"tags":[],"class_list":["post-2426","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-am","category-cuba","category-soviet-union"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2426","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/comments?post=2426"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2426\/revisions"}],"predecessor-version":[{"id":2433,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/2426\/revisions\/2433"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/2427"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=2426"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=2426"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=2426"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}