Thread: Bonding....
View Single Post
  #15  
Old 03-01-2011, 09:01 AM
DaveInDenver's Avatar
DaveInDenver DaveInDenver is offline
Hard Core 4+
 
Join Date: Jun 2006
Location: Larimer County
Posts: 6,562
Default

Nah Nathaniel, I'm a nice fella. Really. ;-)

The Hamsticks are good for what they are, which are compromised mobile antennas. They are not really much worse than any other mobile antenna with the one main downside of having very small diameter coils. But even your Hi-Q antenna is a compromise and on the lower bands relies almost completely on the inductor radiating.

IMVHO the main downside to a Hamstick is they have very narrow bandwidth in general (this is a result of the coil form). They actually have a lot of radiating length, which is good. And they are electrically resonant, which is a good thing.

Don't fall into the assumption that low SWR or wide bandwidth makes an antenna any good at exciting electrons for a given frequency. It's about radiation resistance and uniform current distribution. There is no substitute for physical length and Hamsticks don't fall short there. Also the way they wind the antennas isn't too bad and this really distinguishes a decent antenna from a junk one.

I don't know what definition of radiation efficiency he's using (I assume it's KBG), I'm not sure he is normalizing the measurement correctly to compare apples to apples. There's good reason why 'good' commercial engineering practice is a field of >120 tuned radials over a physical 1/4 wavelength radiator, this has been found to be what's necessary to guarantee a minimum efficiency over all conditions. Nothing about even a well bonded car is ideal and so they all rely heavily on the distributed stray capacitance to find a return. That's the real efficiency problem, the ground, not the radiating element so much.
__________________
'91 Toyota Pickup
'09 Kawasaki KLR650
'12 Gunnar Rockhound 29

"They say the test of literary power is whether a man can write an inscription. I say, 'Can he name a kitten?'" -- Samuel Butler
Reply With Quote