Hi Eddie.
I wouldn't say its impossible to make antenna comparisons. I just think its very hard to make accurate measurements, especially using seperate masts.
the s meter will show relative increases/decreases of signal levels but not accurately. Backing it right off could be as bad as having it fully open.
Most s meters are logarithmic voltmeters (may not be case on digital ones) as are swr/power meters and generally the most accurate/most linear part is mid scale where the divisions are spaced more evenly, at the low end they are very far apart and high end heavily compressed.
When you add an extra mast you completely change propagation paths. That makes comparison more dependent on terrain than antenna, if done on same mast terrain stays the same as do all other parameters. Much more meaningful results. Steady signals also help.
I'm not a believer of same tip heights or i max heights. Its a test of design so mounting location/feedpoint is part of design so should be the same on all antennas.
If you have to add another 9 ft of mast to make tip or i max the same your measuring an antenna against an antenna and mast extension. Its the design your testing so if feedpoint is high or i max low its more a design flaw in my opinion.
it all comes down to how accurate you want your measurements and how important it really is to you. It also depends on what you class high class tools which I don't think are necessary to realise which antenna is better but if you want to know by exactly how much then quality test equipment is essential.
I'm quite happy to use stardusters,penetrators,sigma 2/4, astroplane,mighty magnum 3,vector 4000, top one,clr2,tornado, 827 or any other decent design as all will do the job well i use them for which is mainly skywave dx.
I don't really care if ones a fraction of a s point up on the others, all are proven performers and chances are no-one will notice it.
Jazz 73
