https://www.google.com/?gfe_rd=ssl&ei=6fW8VtuTNYST-gW677OwCw#q=rf+signal+generator+kit
http://www.minikits.com.au/sweep.htm
http://www.edn.com/electronics-blogs/the-emc-blog/4423710/Review–inexpensive-RF-generator
http://www.minikits.com.au/sweep.htm
http://rfexplorer.com/rf-signal-generator/
http://lea.hamradio.si/~s53mv/index.html