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DART-70
=======
In 2023, the 70MHz band became accessible to amateurs in Switzerland. This offers an excuse to build a transciever.
See dart70-blockdiagram.pdf
* Enclosure: Hammond 1411R or 513-0900?
Receive gain:
S9 is -93dBm, S1 is -141dBm
-141 -1 +16 -1 -7 -4 +60 -7 +30 = -55 dBm
Transmit gain:
-6 -7 -4 +16 -4 -7 -1 -1 +15 +15 +15 -1 = 30 dBm
## To order
* Enclosure
* Microphone MH34-B4B
* Ordered:
* Adafruit 292 and 181
## 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
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