diff --git a/README.md b/README.md
index 156bf14..19f4603 100644
--- a/README.md
+++ b/README.md
@@ -57,4 +57,6 @@ understand all of this stuff.
 
 ## Acknowledgments
 Special thanks to [Mark Fickett](http://www.markfickett.com/) for his
-[arduinomorse](https://github.com/markfickett/arduinomorse) library.
\ No newline at end of file
+[arduinomorse](https://github.com/markfickett/arduinomorse) library and 
+[N1OIQ](https://sourceforge.net/projects/kb1oiq-ham-radio-projects/files/80m_ardf/) 
+for similar design insparation.
\ No newline at end of file