[Antennas] From transmission lines to tuners

[Sandy and Kees Talen]

Since it's really an antenna "system", as has been pointed out by 
several, here is a highly recommended article on antenna tuners 
and their losses. The only thing I walk away with is "where do I
find the parts to build a Johnson Matchbox equivalent". The next
thing is how to test your beam (traps/joints, etc) on ALL the 
elements (and not with an ohm meter). Maybe this has been 
covered earlier.

Frank Witt's (AI1H) articles in 1996 QST are most informative 
and certainly indicate you can quickly loose more at the tuner 
than at the transmission line. It also makes a very good case for 
good link coupled tuners like the Johnson Matchbox vs the 
many, more compact, tuners we see today. I can see many of the 
old timers nodding their heads. 

I gather from it, that typical toroid 4:1 balun losses for approx 
1.5:1 or better SWR are on the order of 0.5dB. Higher losses 
on the lower 80m band (1dB ....worse on 160m) are due to 
toroid material selection limitations (selected for good 10m, 
15m performance, can't cover 10m-160m with one type).  

On the Heathkit tuner (similar to many being used today), I can 
see why lowest balanced line losses are observed using a 200 
ohm load with a 1:1 SWR due to the 4:1 toroid balun. Why are
the lowest unbalanced line losses observed using a 200 ohm
load with a 4:1 SWR ? A 50 ohm load with a 1:1 SWR is also
low, but the 200 ohm load is lower according to his data ??

73  Kees K5BCQ