{"id":9281,"date":"2025-03-04T10:42:00","date_gmt":"2025-03-03T23:42:00","guid":{"rendered":"https:\/\/www.homebrewradio.us\/blog\/2025\/03\/04\/honorable-mention-steve-aa7us-dead-bug-direct-conversion-receiver\/"},"modified":"2025-07-22T18:00:58","modified_gmt":"2025-07-22T08:00:58","slug":"honorable-mention-steve-aa7us-dead-bug-direct-conversion-receiver","status":"publish","type":"post","link":"https:\/\/www.homebrewradio.us\/blog\/2025\/03\/04\/honorable-mention-steve-aa7us-dead-bug-direct-conversion-receiver\/","title":{"rendered":"Honorable Mention: Steve AA7U’s Dead-Bug Direct Conversion Receiver"},"content":{"rendered":"<\/p>\n
<\/a><\/div>\n
That receiver is a thing of beauty. Steve AA7U is 78 years old and retired from the electronics industry. Now he does this just for fun. <\/b><\/div>\n

<\/b><\/div>\n
Look closely at Steve’s board. No pads! That, my friends, is the dead-bug technique. It is closely related to Manhattan style, but many builders prefer it. You see it in a lot of builds by Wes Hayward W7ZOI. I have some stuff built by Farhan using this technique. <\/b><\/div>\n

<\/b><\/div>\n
You will also notice the absence of the PTO screw\/coil. Steve made his receiver fixed frequency. But a member of the group has sent him one, so Steve may soon be tuining around the 40 meter band. FB. <\/b><\/div>\n

<\/b><\/div>\n
But all four stages are there. And Steve did for us a lot of useful analysis: <\/b><\/div>\n

<\/b><\/div>\n
Steve writes: <\/b><\/div>\n

<\/b><\/div>\n
Hi Bill,<\/span>

Attached is a picture of my DCR build. I used a fixed VFO since I don’t<\/span>
have a 3D printer (but just learned two folks are offering the printed<\/span>
coil and have just ordered one). Mine is set for about 7130 kHz. I’m<\/span>
using the cheap eBay Chinese audio transformer 1300 ohms. I’ve done<\/span>
bench sig gen checks for weakest CW signal I can hear with headphones, <\/span>
swapping out different DBM diodes. 1N5819 -130 dBm; MCL ADE-1 mixer -129<\/span>
dBm; 1N5711 HCD diodes -127 dBm; 1N4148 -130 dBm. My LO output was about<\/span>
+6 dBm. Note the proper way to check LO output is to disconnect from the<\/span>
DBM and terminate the LO with 51 ohms and measure the RF AC voltage<\/span>
across the proper nominal 50 ohm load, then convert to Vrms and use an<\/span>
online volts to dBm converter to get the LO power. Looking at the LO<\/span>
voltage connected to the DBM does not give a correct LO power reading<\/span>
(SSD and EMRFD also mention this). I see Dean’s latest BPF comments<\/span>
(where I learned of the audio amp R14 100 ohms vs. 10 ohms typo)<\/span>
mentions the bypass cap on the LO jfet to increase LO output. I tried<\/span>
that yesterday and my LO output across 51 ohm load is now about +10.5<\/span>
dBm (from the original approx +6 dBm) . The actual 8.2V zener diode<\/span>
voltage directly affects LO output too, I tested 10 diodes, the lowest<\/span>
was 8.05V, highest was 8.35V–higher voltage of course gives higher LO<\/span>
output.<\/span>

Here’s one eBay seller of the inexpensive audio transformers I used <\/span>
https:\/\/www.ebay.com\/itm\/35612<\/wbr>7836595<\/a>

(I’m 78 and retired from electronics, now do it for fun and hobby; I<\/span>
have a modest bench of test gear–various Siglent stuff including<\/span>
spectrum analyzer, etc. I’ve been homebrewing stuff for many years.)<\/span>

73,<\/span>

Steve AA7U<\/span><\/i><\/b><\/div>\n

<\/span><\/b><\/div>\n
Thanks Steve and ongratulations! <\/span><\/b><\/div>\n

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

That receiver is a thing of beauty. Steve AA7U is 78 years old and retired from the electronics industry. Now he does this just for fun. Look closely at Steve’s board. No pads! That, my friends, is the dead-bug technique. It is closely related to Manhattan style, but many builders prefer it. You see it … Continue reading “Honorable Mention: Steve AA7U’s Dead-Bug Direct Conversion Receiver”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":9282,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,11,12],"tags":[],"class_list":["post-9281","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dc-receiver-build","category-dc-rx-hall-of-fame","category-tj-dc-rx"],"_links":{"self":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/9281","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=9281"}],"version-history":[{"count":1,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/9281\/revisions"}],"predecessor-version":[{"id":9283,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/posts\/9281\/revisions\/9283"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media\/9282"}],"wp:attachment":[{"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/media?parent=9281"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/categories?post=9281"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.homebrewradio.us\/blog\/wp-json\/wp\/v2\/tags?post=9281"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}