This is one of several units from a very large rack mount set made in Denmark.Most of them I had to strip down as weight was to much for me to ship economically from Canada. According to the main manual for these units indicates the ranges of this unit from 1.6MHz to 3.8MHz , 4MHz to 12MHZ, and 16MHZ to 27,5MHz range.This unit is built to last,the ceramic forms are a very heavy dense smooth material and as you can see the wiring is also heave duty and cloth covered.I can make a copy of the applicable pages if you need. ..Check pictures for more details. Check out my other listings of Ham Radio parts,equipment & Industrial. Most items are surplus from Canadian Military -Mil Spec.