The Motorola Helge Granberg designs are almost 30 years old now. Keep in mind they are only engineered to the level that demonstrates the functionality of a part and since then there have been important developments in materials and components. Once you understand that, designt he rest of the required circuitry and the right output filters, you might end up with a decent amp.
Alternatively, for about the same cost, less work and much more predictable results, you can find on eBay PA Units and Filter Units from old transceivers.
Cheers,
Razvan M0HZH
