I'd like to add a BNC so that my frequency counter can read the marker frequency. However I have no idea as to where to "pick off" the signal. Below is a link to a hi-res schematic of the KG-687. Maybe somebody with a lot more knowledge can use the schematic and figure it out.
Many thanks.
https://www.dropbox.com/s/d9uq4v8zda...matic.pdf?dl=0