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#41
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VSWR doesn't matter? But how about "mismatch loss"?
Tom Ring wrote:
Duh, life always violates it locally, but makes the sum total of entropy higer than it would have been. You aren't the idiot you appear, I hope. I guess I should have added a smiley face. -- 73, Cecil http://www.w5dxp.com |
#42
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VSWR doesn't matter? But how about "mismatch loss"?
Cecil Moore wrote:
billcalley wrote: Now my head *really* hurts! This is a VERY confusing subject, to say the least. (And I also thought antenna tuners actually had a *loss* due to their limited Q...I think I'm going to change careers now and just become a pet groomer; or perhaps simply give up completely and work at Radio Shack). Real-world antenna tuners do have a loss but we previously specified a lossless system. Of course, real world tuners and transmission lines suffer losses but we all just live with those losses while striving to minimize them. The point is that an antenna tuner reflects most of the reflected energy back toward the load thus accomplishing a mismatch gain that offsets some, if not most, of the mismatch loss. High SWR transmission lines are indeed lossier than flat matched transmission lines of the same material. -- 73, Cecil, w5dxp.com Close but no cigar. The (now often automatic) antenna tuner is used to transform the native impedance to the transmitter to match the conjugate transformed impedance of the antenna at the transmitter end of the transmission line. The effective result is that the incident energy arriving at the antenna "sees" a matched load and goes out to free space instead of bouncing off the transmission line to antenna interface. This is also why better antennas have reasonable (not far off matching impedance) characteristic impedances; they do not require matching networks physically placed at the antenna itself. -- JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â* --Schiller |
#43
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18:1 all band dipole?
Cecil Moore wrote:
Buck wrote: Cecil Moore wrote: Please explain your antenna and radio. I am assuming you have a solid state rig with an so-239 connector on it for the basic and then you do what? Hi Buck, Please check out my associated web page and then ask me anything that you don't understand. http://www.w5dxp.com/notuner.htm Contrary to what you may have been told, you can change the 50 ohm SWR seen by your transmitter by changing the length of the 450 ohm ladder-line. Now that is a "real" ham radio antenna system, screwampus but it provably works, and is repeatable (by others). -- JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â* --Schiller |
#44
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VSWR doesn't matter? But how about "mismatch loss"?
Richard Clark wrote:
On 29 Mar 2007 13:10:46 -0700, "billcalley" wrote: snip It does matter if you lack a tuner (in more ways that one). Most discussion of "mismatch loss" omits such matters as tuners as it is a separable issue. Combining these topics raises your chance of confusion. 73's Richard Clark, KB7QHC Heartily agreed. -- JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.Â*Â* --Schiller |
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