https://g3xbm-qrp.blogspot.com/2010/09/why-not-to-use-qro-on-136khz.html?showComment=1285040719032
Roger G3XBM's (Mainly) Amateur Radio Blog: Why NOT to use QRO on 136kHz
https://g3xbm-qrp.blogspot.com/2019/01/136khz.html
Roger G3XBM's (Mainly) Amateur Radio Blog: 136kHz
amateur radio blogrogermainly