Dipole with 102s

[The Jerk]

What coax to use? The 'best' that you can afford within rea$on. Nothing wrong with using LMR-400, or the '240, but there are others to pick from.

Oh, one 'opinion' that I will 'share' is that 'spark-gap' type lightning arrestors are totally worthless. Don't waste your money.

What are other options for cable...I was mainly looking at lower attenuation numbers. What would you recommend for a run of 100 feet?

I have some new RG-6 quad shield, actually a lot of it (as in around 1500 feet). I know we discussed the 75ohm feed line and 50ohm transmitter / feed point. I guess my main issue running RG-6 QS would be getting a PL259 on it...unless they make an adapter from cable to a PL259. (ON EDIT: I found a "F" to PL259 adapter, so I'm covered there) Would this require an antenna tuner down the road?

Thanks for that info about the spark-gap deal, that's what I was wondering.

 

[W9WD]

I use this stuff
K1CRA Radio Store - Davis RF "BURY-FLEX tm" Low-Loss RG-8 - EST TO SHIP 6/5/09 Details

but there are others.
Just to give you an idea

Coaxial Cable by the Foot : The Antenna Farm :: , Your Two Way Radio Source!

 

[W5LZ]

One of the things I look at when buying coax is price. No electrical significance with that, but there is an economical one! [It ain't easy being this cheap, you know. A lot of times it just depends on what I happen to have in my pocket at that particular time.] I also look at (or try to) how easy the stuff is to work with. I think you've seen at least one aspect of that with that RG-6. Another part of that sort of thing is the aluminum that's used for shielding in some coax. That stuff is just difficult to solder to, most of the time I'm not going to bother with it. Then again, if I happen to have a few hundred/thousand feet of it, I just might! The non-50 ohm impedance can be dealt with, the aluminum soldering is a bit harder.
It isn't as much a problem as it used to be, but I hate paying for a "name". If there's something else around that has the same characteristics as that 'name brand' stuff, I don't mind using it. The biggy is paying attention to those characteristics. 'Loss' is just one of them, there are others such as power handling ability (take a real close look at that one, in some cases, that 'name brand' comes out on the short end), size (as in connectors), if it's locally available or do I have to pay to get it here, and so on. Same sort of things you do when shopping for anything! Would I tell you to run right out and buy RG-6? No, I don't think I would. But... uh... What do those adapters cost? Also keeping in mind that they are not going to be the absolute most bestest way of doing things. (I haven't done the "F" to PL-259 thingy, but I have done some things like that. It filled the need I had so it's just dandy. Not the best way, but it works.)
So what do you think? Is it feasible for you to use the RG-6? Or not?
- 'Doc

 

[The Jerk]

The RG-6 "Quad Shield" has two aluminum foil and two braid shields...should be easy enough to solder the shield braid. I already have the weatherproof F connectors for the cable...I just rewired my entire house using this RG-6QS, Thomas-Betts connectors, and a single splitter...the increased picture quality is simply undescribeable.

The adapter runs less than $3, probably less than $10 shipped.

How is the mismatch dealt with? I assume a tuner is required?

Another question I had, would a low-pass filter be a good investment (to prevent any possibility of TVI)??

 

[The Jerk]

It isn't difficult to do at all, just takes a little time to find the right 'angle of the dangle'.
- 'Doc

I bet this would be easy with an antenna analyzer?? Like an MFJ-259B?

 

[W5LZ]

An antenna analyzer if certainly a handy gadget to have around, it can tell you several things an SWR meter can't. Would it be easier to use than an SWR meter? Not until you figure out what all it's telling you. I does include an SWR meter though, so it isn't totally a mystery. Would I recommend one for everyone? No. If you honestly don't have much of a need for one (don't mess with a lot of antennas), it's just too expensive.
As for adjusting that 'dangle angle', it's not difficult. When the SWR gets to the lowest point, quit. That 'dangle' thingy is nice cuz you haven't cut off anything as when adjusting for resonance, you just loosened a rope or two. Went too far? Tighten that rope again.
- 'Doc

 

[The Jerk]

How would trees affect things? I may be able to get it higher, but it may be getting into the tree branches (I would trim the real close ones back of course).

 

[C2]

...find the right 'angle of the dangle'.
- 'Doc

The angle of the dangle is equal to...

...the heat of the beat when the throb of the knob is constant.
...the size of the splat on the mat.
...the strain in the veins.
...the heat of the meat.
...the drip off the tip.
...the torque on the pork.
...how often you flog your hog.
...the dingle and the dongle.
...the licks from the chicks.

 

[The Jerk]

I know how buildings, power lines, etc. Affect signal, but what about trees?

I was looking, and I can probably build a tilting mast that would be 20 feet from the ground and would put the tip around 28 feet. It would be easier for myself the work on since it would lay down on the ground.

 

[The Jerk]

This may seem like a stupid question, but will trees affect signal? I'm thinking I could get the feed point right about 20 feet in the air, with the tip around 28 feet. However, the antenna will be up in the tree branches (I will trim the closest ones back).

I'm thinking I can make a hinged mast that would make working on my antenna very easy.

 

[W5LZ]

Sure, trees will affect an antenna. How much, or in what way? Depends on the tree and time of year, season. "Geeze, another depends thingy!" Yeah, well, it does. The more sap in the thing, the better it acts as a conductor rather than an insulator. You will see a difference but trying to guess how much and in what way is beyond me. I wouldn't expect a huge difference one way or the other, just some.
If you've got the choice, don't run an antenna through a tree. If you don't have a choice, do it and don't worry about it. I've done it for years, can't say I've found it all that objectionable.
- 'Doc

 

[ButtFuzz]

I'm ASS U ME N

That the device with which you are attaching the 102"s together with is something like this:

http://www.mfjenterprises.com/pictures/MFJ-347.jpg

YES?

Note the neat method they used to "minimize" grounding to the mast.

Do dat and let 'em droop.

"Your antenna got the droopy drawers!" So what--it's going to work like gangbusters, man. LOAD IT UP!!!

 

[The Jerk]

This site doesn't perform well with my crackberry...it never registered that any of those posts took, so I apologize for the multiple posts on the same subject. I think I can cut limbs back so that they are probably better than 15 feet away. The trees will be probably better than 20 feet away.

I'm trying to buy that President Washington in the classifieds, so that will be my radio for this setup. I will have it reworked by DTB prior to use...make sure its not clipped. I am going to order my adapter tonight to convert over from the RG-6 to the PL259. I will probably buy my "mast" building materials this week, after I get back from Ohio Wednesday night. Probably pick up my second mirror mount to complete my dipole tomorrow afternoon.

The RG-6QS will make a nice install for me, since I have lots of it, and I can cut it to length.

 

[The Jerk]

That the device with which you are attaching the 102"s together with is something like this:

http://www.mfjenterprises.com/pictures/MFJ-347.jpg

YES?

Note the neat method they used to "minimize" grounding to the mast.

Do dat and let 'em droop.

"Your antenna got the droopy drawers!" So what--it's going to work like gangbusters, man. LOAD IT UP!!!

I'm building something similar, using two mirror mounts...but the principle is the same.

I will have more "adjustability" since I can have them 180* out (flat dipole), and I can move them to exactly 90* from each other (inverted V). Using longer bolts, I will simply sandwich the mast between the two mounts.

I'm insulating mine using similar mounts, however; mine will use ring terminals and not a PL259. When its finished, both antennas will be insulated from the mount.

That one actually has some substance to it. There is one that is simply a piece of lexan or plastic...I would think that would eventually "sag".

 

[The Jerk]

Well, its up.

I built a crude hinge to take it up and down easy. Its basically a tee on the bottom of my mast mounted with a bolt through two eyebolts...crude, but effective on this small antenna.

The mast is a 10 foot piece of 3/4 inch galvanized pipe (schedule 40) mounted to the side of my shed (into the shed's frame). It wiggles, but that is expected. It seems plenty strong for this small antenna.

I got to trim some branches (as in 5 inch plus). Should have that done Thursday!

I got the antenna stood, it looks really good...can't really tell its there unless your up close. The legs droop about a foot at their tips.

I also did a trade for some new RG8. Traded a small 2-pill for 100-feet of coax with a PL259. Big stuff, I'm used to running mini-8. I should be able to have the cable run this weekend.

Regarding the coax, how many turns are needed at the feedpoint to make an effective choke?