Balun or no Balun?

[windham]

I am using a G5RV dipole with ladder line leading to coax and then thru it to an antenna tuner and then my radio for my shortwave listening, I do not transmit, do I need a choke balun?

[Nick E]

BalUn is balanced-unbalanced, Right? I think Baluns are only required for transmitting but if the antenna impedance is different than the coax, then i think u might need it for better SWR Readings(Im not a ham, so dont use my idea as a final, ill get back to u once I conlult my handbook.)

[solargator]

In many situations for swling alone, baluns are not absolutley necessary. To be sure, a nicely designed balun can be the difference between hearing broadcasters and listening to manmade noise and atmospherics. Example of no balun needed; simple wire dipole homebrew; approx. 40ft overall, configured approx. 20ft above earth, inverted and sloping. Coax used, simple R-59; which to my understanding is close to 72ohms; which when presented to the external on a portable shortwave radio, does not cause any great decernible listening quality. Say for a T2FD; I'd definetly go with a matching system and proper impeadance rated coax feedline. I belive I have read about the GRV also using a balun in the feedline configuration. Baluns to my knowledge are not just for transmitting. For what its worth.

[Butch2093]

Hi,
I also use a G5RW up about 50 ft with one end sloped for the omni direction. When the ends come together in the middle they come into ladder line and run for about 10 ft and go into a 1 to 1 Balun then into my shack. I also use a tuner. Everything works just fine and I can hear broadcasts from all over. I have QSL cards from Bejjing China and Melbourne Australia, among the many I have. So go with the balun and run coax line into your receiver.

Butch

[nc_swl]

Baluns are used for rx and tx applications. The balun most people commonly see is the one that comes with a TV and because of cable TV rarely need. It converts twinlead from an outside antenna to the cable input on the TV.

A 1:1 balun converts an unbalanced condition to a balanced one, or feeds a 50 ohm antenna to a 50 ohm load.
Other Baluns (eg a 4:1 or 6:1 or 9:1) also match antenna impedance. Each type of line (coax, twinlead, ladderline etc) is either balanced or unbalanced and has a different impedance. All radios have a 50 (actually 52 ohm) impedance.
If the line (lead in from the antenna) has a 450 ohm impedance a 9:1 balun would convert the 450 ohms to 50, or 450/9=50. If my memory is correct, TV twinlead has 300 ohms, so a 6:1 blaun is used.

A line that is mismatched to the load creates signal loss. The next question is the obvious how important is all that.. As far as swl work, the stations use a lot of power, so a balun is not as important as it is for Ham operations..

More important is a good station ground and btw, to perform properly Baluns desire a good ground also..