[TenTec] Tuning Amp on 17 meters

[Stuart Rohre]

Taken with my previous post, just remember this about SWR and resonance. 
  Resonance is just the frequency where the inductive reactance cancels 
the capacitive reactance, BUT, some of the total may not be from the 
antenna alone.  That can be seen where the SWR does not null at the same 
frequency where reactance is zero.  And some of that could be imbalance 
in the SWR bridge measuring circuit.  Items like Bird wattmeters are no 
more accurate than 5 per cent generally, and
if SWR bridges are that good, feel lucky.  There must be a reason you 
generally don't see them rated for accuracy.  For one thing they can be 
frequency dependent, depending on quality of bridge construction.

Stuart
K5KVH