Looks just like the Imax.
Two coils (inner and outer) and all . . .
Yep Robb, but I think the Imax as fewer coils because it has less mismatch to overcome.
Looks just like the Imax.
Two coils (inner and outer) and all . . .
"O yeah, did y'all know the matching coil in the A99 was a single wire and the shield is probably tapped at the resonance point, with one end attached to the outside of the capacitor and the other end attached to the center conductor of the coax, and a the short tail, maybe 3" floating up inside the insulator inside the capacitor? If I could do the drawing like Nav did, I would draw it for you guys that are curious. That is the way it looks to me"
You just described a variable transformer which uses a fixed capacitor to form an impedance matching circuit. Which is exactly what the 'A99' and Imaxx uses.
The same thing can be done by using a fixed inductance and a variable capacitor. Why isn't it done that way? Probably because the variable capacitor for that circuit would be larger and a little more cumbersome to make into an antenna. Both would do the same thing, convert a high impedance to a lower impedance (or the other way around, a lower impedance to a higher impedance). I think that it was decided to do it this way because of the cost, and, because it's not quite as 'touchy' or 'picky' about finding an acceptable match. It's not as hard to do using the permeability of an inductor to do that adjusting and 'finding' as it would be with a variable capacitor and a fixed inductance. (The 'rings' act the same way as a 'slug' on the inside of a coil does.) It isn't the most efficient way of going about it, but it's certainly easier. Another aspect of doing it this way is that because a greater 'usable bandwidth' is always obtained at the expense of efficiency. The higher the efficiency the narrower the usable bandwidth of an antenna. (That applies to almost everything, not just antennas.)
- 'Doc
emmmmmI think we should be interested in effectiveness and leave the efficiency part to the engineers and scientist.
The higher the efficiency the narrower the usable bandwidth of an antenna. (That applies to almost everything, not just antennas.)
- 'Doc
some folks have minions :bdh:
kneel Booty, Homer is here :laugh: