From b50c895ce6ed17c79c9f5198e71763a646acea15 Mon Sep 17 00:00:00 2001 From: "Matthias P. Braendli" Date: Sun, 15 Jan 2023 20:12:03 +0100 Subject: More schematic work on DART-70 --- README-4m.md | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'README-4m.md') diff --git a/README-4m.md b/README-4m.md index 020aeee..c963b76 100644 --- a/README-4m.md +++ b/README-4m.md @@ -40,3 +40,24 @@ In 2023, the 70MHz band became accessible to amateurs in Switzerland. This offer ## To order * Adafruit 292 and an i2c display +* Enclosure +* Microphone MH34-B4B + +## TODO + +* Mixer termination + * https://www.qsl.net/g3oou/mixerterminations.html + * https://www.changpuak.ch/electronics/calc_16a.php + * http://land-boards.com/blwiki/index.php?title=Kits_and_Parts_Mixers +* Check LO level for diode mixers + +## Notes +SPK click: +LM386 was wired as 46dB gain on Picardy 2020 + +LM4865 (20dB gain) + gain stage +and volume control like +https://www.mikrocontroller.net/attachment/315502/Zwischenablage01.png +https://mbonnin.net/posts/2011-01-05_bwaaaaaaaaaaaaaaalarm-clock/lm386.png + +https://groups.io/g/BITX20/topic/4995877 -- cgit v1.2.3