Is it worthwhile to use an RG8X Feedline for SOTA?

 I was just going through reflection loss calculations and comparing efficient and inefficient transformers.

On 60m, inefficient transformer are only 58% efficient.  Even with low SWR - say 1.5:1, the full entitlement available radiated power is only 2.78 watts.  

Compare that with an efficient transformer at 83% efficiency - radiating into an SWR of 6 but matched with an ATU, the radiated power is 3.77 watts.   Full entitlement with no coax losses is 4.15.  one would not want to go through this exercise with an RG174 feedline as the coax losses are worse - available output down to about 2.3 watts.  With very low SWR say 1.2, you are almost at full entitlement even with RG174.

So the lesson learned is - have a resonant antenna, however, in the case of mismatched antenna use the RG8X feedline instead of the RG174 and it always beats the inefficient transformer.

Having said all that, all this efficiency talk can be dominated by antenna configuration for an intended purpose.  Let's say the intended purpose is to work close in chasers on 60m.  An inverted V with an Apex at 20 feet has close to a 4 dBi  at a high take-off angle as opposed to the same end fed wire set up as a vertical (as impractical as that may seem).  The vertical will have a null at the high takeoff angle.  So an efficient transformer even with low SWR will not work any stations and that inefficient transformer will work those close in stations all day long.   There are a lot of factors that have to be optimized for effective antennas and as always - it always pays to begin with the end in mind and work backwards.  What is the purpose, configure the antenna for that purpose and optimal gain, and then worry about SWR second and last transformer efficiency.  It isn't easy.  As often, summit conditions dictate antenna configuration - presence or non-presence of supports and it becomes a "one size fits all" or "one antenna configuration fits all" proposition - the ubiquitous inverted V.