Balun = Power Loss?
 

Folks ---

Last night a ham mentioned that he was going to feed an antenna with 450 ohm
twin lead directly into his antenna tuner because the use of a balun would
result in less antenna gain 1db because of power loss. Comments?

73,

Jim kg6qhp

The tuner has no loss? I need one!!!

Warmest regards,
John
--
Marbles can be used in models with excellent results! However, if forced
to keep using all of mine up... I may end up at a disadvantage... I seem
to have misplaced some!!!


"Jim Cammarano" wrote in message
...
| Folks ---
|
| Last night a ham mentioned that he was going to feed an antenna with 450
ohm
| twin lead directly into his antenna tuner because the use of a balun would
| result in less antenna gain 1db because of power loss. Comments?
|
| 73,
|
| Jim kg6qhp
|
|

Yes, Your friend needs to read Roy's or Walt's stuff on baluns. W7EL
or W2DU. Need to find out why one needs a balun, and what it will do
for you.
73 Gary N4AST

I think you should ask the person who made the comment.

It wouldn't be surprising if some 4:1 baluns have a loss of a dB or so
at some impedance levels. It's very unlikely that a 1:1 balun would have
this much loss. The questions a

1. Why does the person you quote think that the tuner will have less
loss when confronted by the different impedance than the balun had? It's
entirely possible that the tuner's loss will increase (or decrease) by a
dB or more when confronted by the different impedance presented when the
balun is removed. Has he done an analysis or made careful measurements
to confirm that he's actually reducing overall loss with the change?
2. Is the person you quote willing to accept the effects of common mode
current on his feedline which could result from removing the balun? (See
http://eznec.com/Amateur/Articles/Baluns.pdf.) One likely effect is that
the signal radiated in the desired direction will change due to feedline
radiation. Has he determined that he'll benefit from this by more than
one dB?
3. Does the person you quoted really think he'll be able to detect a 1
dB improvement?

Roy Lewallen, W7EL

Jim Cammarano wrote:
Folks ---

Last night a ham mentioned that he was going to feed an antenna with 450 ohm
twin lead directly into his antenna tuner because the use of a balun would
result in less antenna gain 1db because of power loss. Comments?

73,

Jim kg6qhp