Thread
:
Balun
View Single Post
#
1
July 11th 03, 06:11 AM
Telamon
Posts: n/a
In article ,
(Mark Keith) wrote:
Dave wrote in message
. ..
Balderdash. A transformer that correctly drives the co-ax is a
great advantage.
Depends on the radio. Very few modern radios would benefit as far as
s/n ratio. All the transformer usually does is pump up the s meter.
If when hooking up the antenna, the noise level increases, you have
enough signal. Increasing the level does not increase the s/n ratio
unless the radio is half dead. On the lower frequencies, you have so
much signal level with any decent length wire, you could drastically
reduce it, and still have plenty.
On Mon, 07 Jul 2003 11:20:47 -0600, JJ
wrote:
Vince Fiscus, KB7ADL wrote:
There is no real advantage
for a balun on an antenna just for receiving.
Well, there is in some cases. In cases of bad shack noise, you can
drastically reduce noise ingress by adding a good balun or choke.
Also, many directional antennas like yagi's need decoupling for an
accurate pattern. Feedline radiation will skew the pattern. Also with
verticals used for VHF/UHF, decoupling is critical for good low angle
performance. Being all is reciprical, it's as important to receive as
it is to transmit. But, I do agree, as far as s/n ratio is concerned
with an HF wire antenna, a balun or transformer is not generally
needed. If adding matching actually improves the s/n ratio, you
likely have a fairly lame radio. The bigger payoff is reduced noise
ingress from the shack. That will improve the s/n ratio. If you
actually have noise that is... MK
I donıt understand this kind of thinking that you should not derive the
maximum benefit of an antenna that one has gone through the trouble to
put up. Your logic of all the transformer is good for is pumping up the
S meter falls flat when you donıt have enough signal for full quieting
or whether you can make out the program material at all if the signal is
very weak. I donıt see the need to call anyoneıs radio lame either.
Most antennas output impedance is nowhere near the typical 50-ohm coax
and a transformation can remedy that. In addition there are advantages
to preventing the coax interacting with the antenna some of which you
stated above.
Some antenna designs are better at rejecting local noise than others.
They only work if coupled properly to the coax resulting in better
signal to noise.
--
Telamon
Ventura, California
Reply With Quote
