RB wrote:
Geee-----we're on a roll! Thanks for good info on my previous query. Now,
a new one:

Just put a small MFJ -949E tuner into my antenna system.

Thing works great. The only weird thing is I notice the tuning is extremely
"tight" and "goosey". The slightest movement of the variable caps produces
jumps in meter readings. Having said that, I can still manage with it.

Years ago, this kind of tuning effect was from hand capacity, when just
about everything in the shack was RF hot.

However, this isn't what we're dealing with here. Once my controls are set,
touching around the tuner anywhere doesn't alter anything. So, it's not
hand capacity/coupling.

What is this effect indicative of? Just curious.

I suspect it is caused by an effective Hi-Q load on the antenna side of
the tuner. That could be a high reaactive component or a low resistive
component of the input impedance to the coax.

What kind of antenna and transmission line are you using?

I run a 140 foot long center fed doublet withh 600 ohm open wire tuned
feeders and observe the same type of indications on 60 meters. The
resistive component of the input impedance is 10 ohms with 15 ohms of
inductive reactance. It's not a problem, just sharp tuning.