Transmission lines 600 ohm vs 450 ohm vs 300 vs coaxial cable

[Heavy Metal]

Wow read a lot and sounds like 600 ohm is way to go BUT what is its advantages over the rest 450 ohm, 300 ohm and coax cable when using say on a dipole or doublet ect, and why is 600 ohm ladder line so wide vs 450 ohm and 300 ohm. What kinda power can it handle, can it be used on a MFJ-989D wire / balance line setting?

 

[Road Squawker]

don't confuse "twinlead" , "ladderline" , and "windowline"

the spacing/wire gauge is different.

the MAIN difference is the loss when operated into high VSWR.

 

[Heavy Metal]

Ok, got my attention, explain differences of what's I am seeking between them and what your showing, so many different items out their.

 

[Captain Kilowatt]

The line impedance is determined by the size of the conductors and the spacing between them as well as any insulating materials between the wires. Change one of those parameters and the impedance changes. As for power handling, using standard 14 gauge wire you have absolutely NOTHING to worry about unless you have a three phase electrical service entrance to supply power to the finals of your amp.

Open wire line

Ladder line also called window line

Twinlead

 

[Road Squawker]

... what is its advantages over the rest 450 ohm, 300 ohm and coax cable when using say on a dipole or doublet ...

quick and dirty answer,
if you are feeding a monoband di pole use coax,
if feeding a multiband, cut it for the lowest band, feed it with ladderline and use a tuner on the higher bands


The primary advantages of coax with respect to ladder line are

1. most transceivers are equipped with coax connectors, whereas using ladder line requires a balun or balanced tuner
2. coax is not affected by nearby metal objects, unlike ladder line
3. the impedance of coax doesn't change when it rains or snows, unlike ladder line

The primary advantages of ladder line with respect to coax are

1. lower loss at frequencies of 28 MHz and up
2. easier to make connections
3. can drive a balanced antenna (e.g. a dipole) without a balun
4. lower weight

 

[Captain Kilowatt]

quick and dirty answer,
if you are feeding a monoband di pole use coax,
if feeding a multiband, cut it for the lowest band, feed it with ladderline and use a tuner on the higher bands


The primary advantages of coax with respect to ladder line are

1. most transceivers are equipped with coax connectors, whereas using ladder line requires a balun or balanced tuner
2. coax is not affected by nearby metal objects, unlike ladder line
3. the impedance of coax doesn't change when it rains or snows, unlike ladder line

The primary advantages of ladder line with respect to coax are

1. lower loss at frequencies of 28 MHz and up
2. easier to make connections
3. can drive a balanced antenna (e.g. a dipole) without a balun
4. lower weight

Really when it all boils down the only true advantage coax has over a balanced feedline is convenience. It can be run anywhere without due consideration to its surroundings. All other factors vary from one extreme to the other with balanced feeders having almost no advantage over coax (single band 80m dipole) to it having a huge advantage such as high power fed into a multi band HF antenna.

 

[Heavy Metal]

The MFJ-989D has wire/ballance feeling capabikity, just curious on which line to use and which lune basically bottom line to use get most bang out of it for a multi banded dipole or doublet.

 

[Captain Kilowatt]

The MFJ-989D has wire/ballance feeling capabikity, just curious on which line to use and which lune basically bottom line to use get most bang out of it for a multi banded dipole or doublet.

OK I am getting tired and my eyes are bothering me so I FINALLY have to ask......are you really spelling things wrong on purpose or are you ignoring spell checker or are you just hitting random keys and hoping that the predictive text suggests a word? I mean seriously it is very frustrating trying to read and actually understand what it is you are trying to say in ALL of your posts. I know that you have to see it yourself on your end but don't understand why you do not correct it as it would make things a LOT easier for everyone to read your posts. Just frustrated and curious.