Let's discuss ladderline.

[wavrider]

I have used it in the past, all band doublets. full wave loop on 160 It worked.

Used on 40-10 meter lazy H, worked well.

I have one tower by the house, I only have wire antennas on it, I want to keep the wind load down due to the storms, hurricanes we have here in Florida. So no yagi's by the house.

I have several towers in place on a 5 acre plot, I have a station in the house and another station in the shack 400' from the house.

All my antennas are resonant.

The question is, I would like to run about 400' of ladder line to the yagis on the back of the property from the house.

Ladder line seems to be a good option do to low loss on long runs.

Would I be able to use a short piece of coax, then a 9:1 balun to the ladderline, 450 ohm, then at the tower another 9:1 balun and coax running up to the yagi?

Or use the antenna coupler at the house, run of ladder line to the tower a 1:1 balun and then coax to the yagi?

Trying not to use an antenna coupler.

The yagi is a Mosley67B 10-40 meter.

Any of the antenna guys have any ideas? I am scratching my head on this one.

 

[QROdx]

here's an idea for ya.....

You know the 75ohm cable tv trunk line that you can always find in abundance.
Use 2 runs of that from your shack to the back lot.
Cut each the same length and bond the outer jackets together.
Add a ground rod or three along the length, bonded to the outer jacket.
Use the center leads to connect ladder line to for TX & antenna.
Works like a charm and you can bury it and forget about it.

What I did was to have each end come out of the ground into a small hoffman box so i didn't worry about weather proofing.
Shack end tied to about 6' of ladder line terminated with banana plugs that plugged into a disconnect console on the outside of the shack.
All radios used coax to the disconnect panel on the inside of the shack.
At the tower end, in the hoffman box, the ladder line connected to the trunk line and left the bottom of the box turned upward (with a steady twist to avoid nulls) to 20" stand-offs spaced maybe 30' apart on the 100' tower, terminated into a steerable 160/80m dipole with reflector.

In your case, since you're wanting to use a yagi, you could use the same trunk line idea and just feed it with coax at each end for ease of connection and let'er rip.

 

[wavrider]

Is there a part number for this 75 Ohm trunk line? I can look up the specs for it, and see what the loss would be on a 400' run say at 30 mhz.

at 3.8 and 1.9 mhz there is not much loss, even in mini8 on long runs but the higher bands start to become drastic in DB loss.

Just tossing some ideas so I can operate the yagis from the house station instead of going to the other ham shack. Of course all rotor controls are at the ham shack so I just point the yagi at EU and leave it there.

thanks for the reply

here's an idea for ya.....

You know the 75ohm cable tv trunk line that you can always find in abundance.
Use 2 runs of that from your shack to the back lot.
Cut each the same length and bond the outer jackets together.
Add a ground rod or three along the length, bonded to the outer jacket.
Use the center leads to connect ladder line to for TX & antenna.
Works like a charm and you can bury it and forget about it.

What I did was to have each end come out of the ground into a small hoffman box so i didn't worry about weather proofing.
Shack end tied to about 6' of ladder line terminated with banana plugs that plugged into a disconnect console on the outside of the shack.
All radios used coax to the disconnect panel on the inside of the shack.
At the tower end, in the hoffman box, the ladder line connected to the trunk line and left the bottom of the box turned upward (with a steady twist to avoid nulls) to 20" stand-offs spaced maybe 30' apart on the 100' tower, terminated into a steerable 160/80m dipole with reflector.

In your case, since you're wanting to use a yagi, you could use the same trunk line idea and just feed it with coax at each end for ease of connection and let'er rip.

 

[QROdx]

Ask your local cable company for a part number.
This is the silver coax that's run from pole to pole for cable tv.
normally they will let you have all the "scrap" or tail ends that you want, some will even give you reels of it.
Comes in two flavors, 3/8" and 5/8", at least around here.
The last batch that I ran across was commscope and there was no identifiers on it anywhere.

as for loss up to 30Mhz, if you do what i was explaining you will have balanced line with near zero loss.
just use one center lead for shield/ground and the other center lead for center/hot to your TX & ant.

 

[wavrider]

thanks I will look into that

 

[W5LZ]

Another idea is to just run that ladder line directly to the yagi's feed point and use that 'coupler'/tuner in the house. The only problem with that is keeping the ladder line from wrapping around the mast/tower. Impedance mismatch? Yep, but it won't make a hoot's worth of practical difference. A yagi is a balanced antenna, ladder line is balanced. It used to be done quite often. One variation was a 'slip-ring' type of feed to the yagi to keep from wrapping the ladder line around the support.
- 'Doc

 

[Captain Kilowatt]

Ask your local cable company for a part number.
This is the silver coax that's run from pole to pole for cable tv.
normally they will let you have all the "scrap" or tail ends that you want, some will even give you reels of it.
Comes in two flavors, 3/8" and 5/8", at least around here.
The last batch that I ran across was commscope and there was no identifiers on it anywhere.

as for loss up to 30Mhz, if you do what i was explaining you will have balanced line with near zero loss.
just use one center lead for shield/ground and the other center lead for center/hot to your TX & ant.

Actually the losses are twice that of using a single length of the same cable ( and so is the impedance) so it is not really nearly zero losses. It is a good idea for running balanced lines where a normal balanced line is impractical to use.

Typical losses for 3/4 inch CATV trunk line is about 0.25 dB/100feet at 27 MHz so it would have about 1 dB loss for a 400 foot run. Not too shabby.

 

[wavrider]

Thanks for all the replies.