http://lz4ha.chepelare-bg.net/joomla/index.php/my-constructions/78
---------
http://ua6hjq.qrz.ru/voip/mmdvm.htm
----
http://f6kbf.free.fr/html/ADF4351%20and%20Arduino_Fr_Gb.htm
----------
https://vk6ysf.com/sdr_hf_up_conv.htm
-----------
https://officinahf.jimdofree.com/antenne-per-i-4m-70mhz/4m-delta-loop/
----------------
https://g0wfv.wordpress.com/how-to-auto-start-mmdvmhost-as-a-service-on-boot-in-raspbian-jessie/
--------------
https://www.rtl-sdr.com/forum/viewtopic.php?t=5263
-------------
https://www.rtl-sdr.com/rtl-sdr-tutorial-setting-up-and-using-the-spyserver-remote-streaming-server-with-an-rtl-sdr/
-----------------
http://kmkeen.com/rtl-demod-guide/
--------------
http://jcoppens.com/ant/qfh/calc.en.php?fbclid=IwAR3uK2V6lkkFykrDBbDPG3CWPCywQ7Al20qTgdmEWcC-DOBE3f0mYJt60iQ
---------------------------
https://www.petervis.com/electronics%20guides/dynamic%20noise%20reduction/dynamic%20noise%20reduction.html
-------------------------
https://github.com/ha7ilm/openwebrx
------------
https://github.com/jketterl/openwebrx
----------------
https://github.com/moneriomaa/openear
-----------------
-----------
http://rsws.zapto.org/RadioSoftware/Motorola/Motorola.htm
-----------
https://www.cqrivne.com.ua/samodelkin/shemy.htm