[G6Tanuki]

2N3055 exist in two versions - hometaxial and epitaxial.

The earlier versions had limited HF gain; later versions had better specs and would happily serve as 'top band' RF-amps at 1.8MHz.

If you had to replace a failed 'early' 2N3055 in an essentially DC circuit - something like a voltage-regulator - and you used a later top-band-PA version, you could often run into oscillation and instability issues that the original circuit's designer never had to deal with.