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W2KS
01-04-2008, 03:59 PM
I am thinking of using and hanging a G5RV(102ft) antenna for my base satation and multi-band use in my back yard.However, I am limited for space. I would like to install the center feed at the apex of my roof peak (35ft), and have the ladder line come down the side of the house, over a second roof and then conected to coax leading into my basement shack. Also, I would extend the wire elements out to two old trees in my back yard (my property is about 35 feet wide, which would give the antenna a configuration of a flat top V. Is there a required angle of seperation which is necessary for the antenna to work properly, and would this configuration work? Also, should I use an antenna tuner?? Any advice would be great.
Thanks and 73's Ken W2KLS

T

WB2WIK
01-04-2008, 04:16 PM
You will *always* need an antenna tuner with a G5RV, that goes without saying (even per the design, per all the published articles and data sheets, etc).

The configuration you describe is way less than ideal (horizontal vee). I'd keep the "angle" between the legs as "open" as possible, preferably more than 90 degrees.

What would work a lot better is if you can raise the center up to higher than 35 feet (apex of roof peak supplemented by a long mast or pole to support the center of the antenna). That way, you can create more of an inverted vee configuraton (high center, lower ends), which allows more flexibility in the installation.

WB2WIK/6

KZ4Y
01-04-2008, 04:31 PM
Hi there,

I'm no expert on G5's. First you should know that the G5 was made for 20M and any other band is a compromise. So, yes you will need a tuner. Just about any configuration will work provided you don't hang it low to the ground and let the ladder line draw the ground. I have mine on top of the house who's peek is about 37 feet. The sides of the antenna run diagonal along the sloping roof line - to get the max wire amount on the roof then across for any extra wire that didn't make the diagonal - about 5-6 feet on one side of the dipole. Anyway, the ladder line goes down to about 10 feet from the ground to the balun and coax. I have had good luck with it; but, for my particular situation, I added another 12 feet of ladder line - seems to work better for me than the standard length. So, what you have will work for you.

GL
Ken

N3QVB
01-04-2008, 06:15 PM
I have the 102-ft. G5RV and am blessed with plenty of room, so it's fully extended. The most important thing to remember for maximum efficiency is to try to keep the ladder line as close to a right-angle to the wire as possible. Also try to get that ladder line as fully extended as possible (I think it's about 33-ft. long). And, you'll definitely need an antenna tuner. My G5RV is up about 35 feet and works great. Good luck with yours.

Andy

G0GQK
01-04-2008, 10:42 PM
There's nothing magical about a G5RV. A dipole 90 feet long and a dipole 135 feet long will work equally as well. Use 300 or 450 ohm with a good ATU and the feeder can be as long or as short as required

G0GQK

EI3GAB
01-04-2008, 11:47 PM
I'm no expert but I would imagine that trailing the ladder line down the roof would produce undesired effects due to ground issues, I would have thought running a coax feed line may be more suitable to your location but I may be wrong here ?

maybe someone in the "antenna know" will advise ?

WA3ERQ
01-05-2008, 12:15 AM
Ken;

I have both a Titan-DX vertical and a G5RV both on my roof and the G5RV outperforms my Titan on all bands. I have mine almost the same way you want yours. Due to space limitations, I have the apex on my roof supported by an 8 foot piece of PVC with a homebrew base of PVC. Both legs run down and out so my G5RV is not a perfect inverted "V" since the apex is not directly over the legs. It's more on an estimated 45 degree angle. I'm running an FT-897D with the AT-898 tuner which is required. The ladder line runs directly down to about 6' from the ground where it enters my house. Right inside the house I have the ladderline connected to an SO-239. Immediately afterwards, I have an air core balun which is basically just 11 loops of RG-8X then running to my antenna switch. I've gotten fantastic signal reports but I'm sure that if I could install it as a perfect inverted "V", I would get even better results.

I can email you a photo from google earth of my house with the antenna lines drawn over to give you an idea on how I did it. I don't have 102' in any direction and although you can let some of each leg hang down a little, that would mean supporting it even higher.

At first I had each leg going down to about 8' from the ground but I read somewhere that it should be at least 15'. I made this adjustment and didn't see any negative or positive results.

Good luck.

'73
Jim
WA3ERQ

W2KS
01-05-2008, 01:13 AM
Jim (and all others)
Thanks! If you could send me some pictures, that would be great!! One of my rigs is the FT 897 w/tuner. kens919@optonline.net[/EMAIL]

73's Ken W2kls

KD6WAG
01-05-2008, 06:56 AM
I have the "Radio Wavz" "G5RV-Lite" which is a bit smaller than a standard G5RV. I have an aluminum painter's mast which goes up only 24 feet. I hang the apex up to the top of the mast and slope the ends at an inverted "v." I placed the painter's mast inside a 5 gallon bucket with a piece of pvc pipe inside some quick dry cement. I then slide the mast in the bucket.

In order to keep the G5RV's lead line away from the aluminum mast, I actually pull the lead line out at about a 45degree angle from the top of the mast. The end of the lead line ends up about 2 feet above the ground. I then hook up the coax cable with no balun and run 50 feet of coax into the house to my LDG 200Pro auto-tuner. Works for me.

I belive that if you let your ladder line down the side of your house, the chicken-wire mesh just behind your stucco might affect SWR on that G5RV. So, you might also want to pull the ladder line away from the side of your house. Play with your SWR and see what happens.

KN2RC
01-07-2008, 12:25 AM
ken....am i more then 5000 feet west/southwest of you? #is your property similar to mine-50' x 200' with the house WAY forward on the property? #center-fed LONG wire antennas did not lend themselves to easy installation, and no matter how i configured them, one of the neighbors trees ALWAYS won out over 12-14 guage wire. #'par endfedz' allowed me to run the antennas in a straight line, albeit with nulling of north & south signals. #unfortunately, 7+ band operation is not going to happen without looking like the overhead of an amtrak station north of nyc. #but, i chose a few bands i'd prefer to be able to be fairly effective on & went that route. i feel performance on 12 & 40 is superior on the endfedz vs the g5rv JR i had....20 usually seems better on the par then the jr-it's closer to 1/2 wave then the jr & no tuner is needed with the endfedz. #plus, i have no ladder-line issues to worry about, lmr240 on 20 & 40, 8x on 12, and losses don't seem to be enough to make me have to yell too often. #stacked loops for 6, 2 & 432 on the same roof mounted mast & an old cb antenna for 10m & i can have just as much fun as the next guy! #during intense periods of E skip on 10m, my vertical cb antenna got me every single contact i attempted, even when the other station was running horizontal.
after construction/landscaping is done, those 3 endfeds will be re-situated & i will probably try to get either the g5 or jr version (or even off center fed windom) up as well just to have 'coverage', however efficient or inefficient it turns out.

W2KS
01-07-2008, 02:03 AM
Bob,
I've spoken to you before on 10m and 2m, and yes, my property measurements are almost exactly the same. Presently I am using the end-fedz for 40,20,and 10m with excellent results. I was looking for something that could give me all bands with a tuner. I was even considering a Challenger DX, but they are too unsightly. I'll probably stay with the end-fedz, and go with their 17m wire and 6m element. I'll just run more 8x into my shack. For dual band, I'm using LMR 400 because of the loss issue. Thanks for the help. I'll try and get you on 10m. Stop by some time to say hello.
73's Ken W2KLS

WA8RTI
01-08-2008, 08:40 PM
From April '06 to November '06 I had a 102' homebrew G5 up as a inverted V with the center at about 35' and the ends at about 10'. #Running a barefoot 746 Pro I made a lot of contacts on 40, 20, and 17. I think I got about 25 countries in Europe, Africa, #and S. America. And I got Europe on 40 meters. All contacts were SSB. It may be a compromise but I was very happy with the performance of the G5. A 60mph wind took down my mast and then we moved into town and although I have a double lot, I really don't have room to put the G5 up again. #I just took delivery of the MFJ 80-2 meter vertical and will have it up in the next few days. I will be running LMR 400 since the one line will be feeding all the way up to 2 meters and losses on anything else would be to high.

M3MVB
01-10-2008, 12:50 PM
Thats the same as i have at the qth abt 35 feet up in a horizontal vee but only about 45 degrees apart, fed with 300 ohm twin via a LDG Z-11pro aatu from a 875 not ideal but i get good results and GDX (usa/south america on 10 watts) feeder does need to be at 90 Deg to the elements though just experament with it
Steve m3mvb

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