[NLRS] VHF Amplifiers

[Jon Platt]

Thoughts on VHF amplifiers:
For general operating, more power is always better than less power.  
For contesting though, there are rules.  For the three ARRL contest, the SOLP is 200w PEP or less on 6 and 2m, 100w PEP or less on 222 and 432 MHz, and 50w PEP or less on 902 and above.  If you are over these power limits on any one band then you fall into SOHP category.  The ARRL contests also has a SO 3 band category in which you would be limited to 100w PEP or less on 50 and 144 MHz, and 50w PEP or less on 432 MHZ; just these three bands.  The current ARRL rules do not make a power limit distinction for multi-op or multi-op limited as both can run legal power; there is no low power multi-op category, just "multi-op".   For CQWW VHF, which is just 6m and 2m, there is no power classifications except for SO QRP which limits you to 10 watts or less on all bands.
Your FT991 provides 100 watts on 6m and 50 watts on 2 and 432.  That alone puts you in good grace for SO3B with full allowed power on 6m and 432, and only 3 dB down on 2m.   If you wanted to, you could look for a solid state 2m amp that gets you up to 100 watts but its of questionable value. ..If you want to jump into the SOLP category you have some room there to go from 100 to 200 watts on 6m (3db), 50 to 200 watts on 2m (6dB), and 50 to 100 watts on 432 (3 dB).  Again, adding a solid state 2m amp at first may be the best value as that gets you close to 6 dB of gain on that band.  If you enter the SOLP category you would be competing with other SOLP stations that may have more bands.  Adding those more bands gets to be more work, more cost, etc, but sure is a lot of fun !   Note that the ARRL's Limited Multi-op is any four bands (or less).  ..If you want to go big, especially for say CQWW VHF and the June contests, go for high power on 6 and 2m.  One consideration for you would be the availability of 110VAC vs 220VAC when adding a high power amplifier.  Lots of guys are having fun now days running such high power and using all sorts of modes, including digital, to work lots of stuff.  ..So, to summarize my random thoughts, you are probably well suited right now to jump in with a competitive SO3B station with the FT991.   Improvement after that may be to add a 2m 200w solid state amplifier (?) to either run it at 100 watts for SO3B or full power for SOLP.   Given that you have lots of 2m drive (i.e. 50w), you can go with something like a Mirage B-320-G, 50w in give 200w out.   After this, the return on investment dwindles unless your thinking about going truly high power in which case you may need 220VAC, I defer to others on that subject.
I await to see what others may think...73, Jon  W0ZQ