Flat top w/ 50ft. Vert and about 90ft Horiz. to work with.

[Superhet66]

thanks Tom
I guess the G5RV will end up a receiver only antenna or a portable QRP jammiedoo....  

I have to admit, when I grabbed the 500' roll of 10# ( with a grunt ) I had second thoughts. I looked at 14# & 12# but stuck to me guns. Once you pull the insulation back it really isn't that bad. I'll support it well in the center & it will be fine.

If my idea works out for securing the ladder spacers it will be one for the books ( or the trash...)

I have plenty of wire, insulators and spacers left for a heavy 10m / 20m diaperpole. That will be next. I can make up a wound coax/PVC balun to get me from open wire to RG8U and around to my shack.
 Lossy: maybe. Excuse to use ladder line: Yes  

P.S.
 Duty Cycle:
The AM vs. SSB duty cycle was pointed out and made a believer out of me as far as beefy components for AM service. I never thought about it before.

                                      
                               Is it Friday yet? I have stuff to build...
                                                                 DJ

[Superhet66]

Hah, I just opened the Yazoo link. Based in Nashville TN by pure coincidence  
That's a well constructed web page.
Text book perfect weather here, I need to get away from the damn keyboard!!
                                                          73    DJ.  
                          

[K1JJ]

"I have plenty of wire, insulators and spacers left for a heavy 10m / 20m diaperpole. That will be next. I can make up a wound coax/PVC balun to get me from open wire to RG8U and around to my shack."


   It's very important to go into a link coupled tuner for the openwire to coax transition, esp on 10-20M.  You will get a 1:1 on any freq with minimal loss.  Using a balun is guesswork and will be way off on most freqs.

Do a search here for "K1JJ Tuner" and build two tuners -  one for 10-20M and one for 40/75.  Buy two 500pf vac variables on eBay, get some copper tubing and you can make two easily.

Tuner schematic:
http://amfone.net/Amforum/index.php?topic=18054.0

T

[Superhet66]

Yep, I see now.
I thought the wound baluns were broader than that. Now that I look at it, I guess it's the nature of the beast, as it's a fixed value. The K1JJ tuna is within my ability fabrication wise. I'll look at some of the working examples out there.
 
Lightning protection is also on my reading list. I need to condense the crap load of information out there and tailor something reasonable here. As it is now, I disconnect every thing, toss it out the window and clamp it to ground away from
the house. A few weeks ago I awoke to the sound of rain & thunder at 2am. I scrambled and was shunting and grounding leads in boxers shorts and slippers, in heavy rain, waiting to get lit up. Catskill electrical storms are fierce and sudden. I have a nice old, large, Con-Edison knife switch that I will put to work soon.

I appreciate the patience. I like working with this stuff, it takes me out of my comfort zone knowledge wise. Waaaaaay out some times. 

                                      Is it Friday yet? I have stuff to build.
                                                              DJ


 

   
 

[K5UJ]

The coax wound on the PVC in the photo looks like a coax choke.  If they are wound with the right coax; right no. turns and diameter for a given range of bands, they are find for choking off common mode RF (RF on the outside of the shield) but I don't know about using one for Z transformation and even if that's possible I would go the link coupled tuner route.  Coax chokes are superior to bead 1:1 ununs as common mode chokes because they don't heat up and saturate. 

Actually disconnecting everything and throwing it all outside is pretty good lightning protection.  that's basically what I do.  You just have to get in the habit of having everything off and disconnected and all the antenna feeds pulled away outside all the time in storm season except when you are at home, awake and able to react quickly.  I do this at night and when I'm away from home.  The only time I relax and leave everything hooked up is in the dead of winter.  When it's -20 I figure the chance of a thunderstorm is pretty low. 

I don't want to discourage you or anyone from going all out with all lines bonded together at the AC service entrance; everything bonded so it rises to the same potential during a hit and all that, with a buried perimeter ground strap all around the house, cad welded to rods every 15 feet or so.  I'd like to do all that but I'm not a broadcaster who has to have a station on the air all the time no matter what, in a site that is designed from the ground up for radio transmission.  I'd love to plow the property and lay down gravel and dig trenches and turn the place into a real radio station but I'd probably have a torch procession to my front door if I did all that.   So I just unplug everything and pull the feedlines away from the house outside and let it go at that. 

One thing about lightning I never hear the experts dwell on (they're all full of cadwelding and bonding everything, and gas discharge units blah blah) is that no matter what you do, 50 amps at 100KV is going to go where it wants and professional transmitter sites with all the protection you can think of, often have gear get zorched in a thunderstorm.   But they have the do rei mi to just go out and buy a new rig, processing box or whatever they have that got fried.   As a ham, I do not, and since I don't have to be on the air all the time, I stick with the disconnect insurance plan.

[ka3zlr]

If yer gona throw it all outside don't forget to unplug an disconnect the grounds too.

73

Jack.

[Superhet66]

 A bit of knowledge led me astray.
( again, I need to read more and Bullsh*t less. )
I'll use the J-matchbox in the meeny time and build a link coupled tuner down the road. I like the remote, step motor driven version that pops up in a search.

Yeah, it ALL goes out the window, including the ground cable and gets clamped to a 8' ground rod. I unplug all line level stuff in the shack and get the cables away from the duplex outlet.
My place is/was a cob job from the last owners, electricaly and plumbing wise. I'm going to bring dedicated BX fed quads up into my work area, right off the panel.
My plumbing is copper free. It's all PEX. Some hate it some love it. I used PEX because it's a temp situation here and PEX will survive freezing. My house needs to be Bulldozed and i can't see plumbing it out in copper.
On the subject, I wonder what PEX vs. copper plumbing does when lightning comes to visit. The shadow knows.

SO...
I plan on loading up and actually modulating this weekend. ( Do ya' hear me Bear? )
Lord have mercy....

[WBear2GCR]

Mmmm... well good luk!

I gave '2YOI my suggestions in a private email.

it boiled down to this: get on with the simplest thing you can.

I'll be listening this weekend... try in the AM or after ~5 in the afternoon when conditions are best...
Talk to whomever you can!

                    _-_-bear

[Superhet66]

While feeding the mosquitoes, gnats and black flies my blood, I figured I'd put the 130' dipole together.

I measured out two runs of the 10# wire for each half of the dipole and the drop, secured to a tree with a few feet extra for breathing room. I then secured the other end to a piece of pipe and drew a foot or so more out of the wire to pre-stretch it and create pin straight runs to work with.


I chose to thru-drill the PVC separators, not just slot them. I made a jig up and took my time.
It was an unexpected PITA! Despite a solid drill press, good drill bits, a "V" block, "C" clamp and patience, getting consistent, parallel, spacing was tough but I got it.

What I learned was:

Use the "Gold" PVC 1/2" pipe from Home Creep Show. It does stand up to UV and is very tough stuff. I tried to shatter it, it just compresses.


Find the off-set from the ends to give you the distance between conductors.
Chuck a fine point Sharpie marker in the drill press. Make a simple jig with a stop and mark the circumference. Rotate the piece with the press locked and the tip just touching the work. You should be able to slide the pieces in and out and not crush the marker tip.

Lay the piece in a piece of angle and mark a line the length of the tube to create 2 cross points for drilling. Use as fine a marker as will work. This improves accuracy.

Lock the bit as far up into the chuck as possible to minimize flex.

Don't flip the work to drill the 2nd hole. Any skew will go in the opposite direction and double the error if you flip the piece to drill the second hole. Slide the piece over in the V block.

It sounds obvious but the bit will want to walk off the radius. Allow the bit to bite a bit before applying more pressure.

Use a counter bore, a larger size bit or chamfering bit to clean up the sharp edged holes. This payed off in a big way as i went to slide the 30 or so separators along the 65' of 10# wire. They would have been biting into the PVC skin the whole way.

Slide the tubes along one at a time. Sliding 2 will bind up and grab the jacket & tear it. One in each hand at a ft. or so apart sped things up.

Use bug spray.

The pay off is a very clean, solid, uniform look to the ladder feed.

I'm using UV resistant zip ties inside the tube to trap the wire, 1 per side. Then I squeeze a dab of heavy duty PVC glue on each side from a 50cc vinyl irrigation syringe. ( drug store item ), This fuses the PVC wire jacket and pipe. Little or no space is left for critters to move but water can escape.

The potential center support is beefy, no?  
I'd like to turn a ribbed center support my self out of polycarbonate stock. The Pyrex is heavy, fragile and part of a set I don't want to screw up.
 I hope it lasts a while.    
              
                                     D.

[K5WLF]

Try this................been using it for years with no complaints. Workz good if you're a little stuck for space. With the right tuna, it'll get ya 160-10. It dont strap on 160, but it does work. It straps pretty good on 80, and 40. Especially if you got a little horsepower to push it. Although I have used it with piss-weakers and still been heard without any problems.

Frank,

I'm space-challenged on a midget city lot and that design looks real interesting. Two questions. One, your drawing shows a vertical length of feedline before it heads off horizontal. Is there a specified length of the vertical run (like a G5RV) or was that just for convenience in drawing? Two, how robust a tuner is required if the antenna is fed with a DX-100?

Thanks,
ldb
K5WLF

[W4AAB]

The insulating material mentioned earlier is called Delrin. I am trying to get my 268 foot center-fed dipole up soon(fed with crap brown OWL).

[The Slab Bacon]

Frank,
I'm space-challenged on a midget city lot and that design looks real interesting. Two questions. One, your drawing shows a vertical length of feedline before it heads off horizontal. Is there a specified length of the vertical run (like a G5RV) or was that just for convenience in drawing? Two, how robust a tuner is required if the antenna is fed with a DX-100?
Thanks,
ldb
K5WLF

the length of the feed line is not critical, However you might have to adjust it some to keep from having a current node right at the tuna. IIRC, mine is somewhere around arond 50' or so. It's been a while since I even looked at the sketch. I am using 14ga crappy brown stuff for feedline. (I was too lazy to make my own)

One of the larger mofojunk type tunas should be OK-FINE with a DX a hundred class transmitter. Just dont use one of those little dinky ones. If you plan to run legal-limit (or more)  class power, you should get serious and build a beefy tuna. I have used mine with a Valiant and one of the bigger mofojunk tunas without any problems. The 4X1 rig, however is another story, that brought about the end of that tuna and the need to build a serious one!
   

[K5WLF]

Frank,
I'm space-challenged on a midget city lot and that design looks real interesting. Two questions. One, your drawing shows a vertical length of feedline before it heads off horizontal. Is there a specified length of the vertical run (like a G5RV) or was that just for convenience in drawing? Two, how robust a tuner is required if the antenna is fed with a DX-100?
Thanks,
ldb
K5WLF

the length of the feed line is not critical, However you might have to adjust it some to keep from having a current node right at the tuna. IIRC, mine is somewhere around arond 50' or so. It's been a while since I even looked at the sketch. I am using 14ga crappy brown stuff for feedline. (I was too lazy to make my own)

One of the larger mofojunk type tunas should be OK-FINE with a DX a hundred class transmitter. Just dont use one of those little dinky ones. If you plan to run legal-limit (or more)  class power, you should get serious and build a beefy tuna. I have used mine with a Valiant and one of the bigger mofojunk tunas without any problems. The 4X1 rig, however is another story, that brought about the end of that tuna and the need to build a serious one!
   

Thanks, Frank. That's what I needed to know. I've got one of the Mighty Fine Junk 941E's (300 watt) sitting on the shelf. I probably should get a bigger one, or just build a K1JJ tuna in preparation for the day when I finally get some high power excitement happening. I'm currently running a coil-loaded 97' LOA dipole on 160 and it seems to radiate pretty well, but the bandwidth is dismal. Think I may just have to get busy build a new antenna.

Thanks again,
ldb

[The Slab Bacon]

Just keep in mind that you are dealing with the short antenna / high feedline current scenario. Anything you can do to minimize I/R losses will work in your favor.

Good luck and have fun! !  You won't regret it!

[WBear2GCR]

Yo, guys...

The OP, made the post a year ago or more now... since then he got his ladder line up, had a FB signal, also got his license, and since then moved to a new QTH in the same area, and has not been heard from on the air for some time...

                  _-_-bear