Longwave AM transmitter based on the XR-2206

Some years ago I described some AM transmitter experiments for the longwave band from 150 to 300 kHz. A transmitter that worked over a few meters was based on an XR-2206 function generator IC. Instead of building it from scratch as that first article indicated, I ended up purchasing and modifying the "Geekcreit® XR2206 Function Signal Generator DIY Kit Sine Triangle Square Output 1Hz-1MHz" from Banggood. 

That kit is not intended for AM modulation as the modulation input, pin 1, is grounded. It therefore needed these modifications:

Low power longwave transmitter experiment

Many places in the world, low power transmitters in the medium wave band are allowed. I am talking about regulations like in the US where FCC part 15 allows up to 100 mW input.

In Norway we have a particular permission for members of the Norwegian Radio Historic Society to transmit up to 500 mW on 216 kHz in the longwave band. I'm not sure if this is output or input power [it's output power]. The permission is meant to cover a personal collection of historic radios. The frequency is the one used by the main transmitter north of Oslo from 1954-1995 running 200 kW. The frequency is still allocated to Norway, so I guess that is why we may use it this way.