G5RV dipoles ?..

[KD8NIV]

Ok sounds good...

Just want to play with this G5RV some to see how it does in my situation....this is a totally different situation than most people has to deal with...not having a tree in the yard to use is bad enough, but having power lines and all the metal is something else to deal with.......I'm in a trailer park, this is where all the metal comes from....

This G5RV is one of them built by Oasis, from what I have seen......the noise I get is bad...not sure what a person can do about that....

The thing is, the ladder line is off the ground, and the swr is running from the 10m band 28.325 down to 7.2 on the 40m band swr is a 1.1.......on 7.3 swr is a 1.5, I just use this as a reference point....and on the 80m band 4.0 to 3.8, swr is high because, the auto tuner keeps trying to tune it everytime you key the mic......but thing is, my swr has never been this low on the other bands, in which I have moved the ladder line 3 times or so, probably leave it here for now....hope to work you guys out there on the radio sometime....

 

[KD8NIV]

Had some bad wind here today, and the ladder line stayed on the roof, so looks like I'm going to have to do something else with it, this stuff is thinking 32' long, can only imagine with it would be like with a 40' piece of ladder line....

 

[KD8NIV]

Ended up hanging the ladder line on a 20' joint of PVC pipe, and its right at 20' off the ground right now.....it talks really well there, pretty much talks anywhere you want into the west, and into South America, but not able to work stations into Europe.....don't have the room for another dipole, so may make a change with this one soon...

 

[KD8NIV]

Have a question for your guys, still running the G5RV dipole....

I have moved the ladder line all around here to keep it off the ground, ok right now I have it on a 20' piece of PVC pipe and the choke is a little lower on the pipe, and using a 50' piece of RG 213 coax, swr is running a 1.1, using a auto tuner....this is on bands 10-40m....

Ok 80m won't tune when the ladder line and coax like this....I even tried to add coax to the 50' and it still didn't help it any...


Back when the ladder line was hanging on my back porch, and I was using 120' of lmr 400uf coax on it, it did tune for 80m easy without any problems, as well as the other bands....

Why has the swr changed like this, is this normal ?...

 

[prcguy]

Yes, that's normal. Remember a G5RV is designed as a 20m antenna and its big enough to work ok on all bands 80 through 10m but with a lousy match, especially on 80m. When you add more coax or go to a higher loss coax it makes the match appear better at your tuner. Some auto tuners can tune a 10:1 match ok and will work with a G5RV and a short run of coax, some will not.

Some companies recommend at least 70ft of RG-8X on their G5RV and more if you are using lower loss coax, What they are saying is add an attenuator in line and loose some signal in order to match their antenna. Not a good way to do business....

One way around the problem is try adding various lengths of coax until it matches. Personally, I would change the G5RV into a ZS6BKW version, which is about 93ft long and shorter than a G5RV but the ladder line is about 10ft longer at around 41ft. The ZS6BKW has a good match on most bands without a tuner and its not that bad on 80m where the tuner inside my K3 will match it with only about 30ft of LMR400 coax.

What you get with the ZS6BKW over a G5RV is the better match on nearly all bands, which means less feedline loss since its no longer working into a terrible match and the end result is usually a better signal on all bands over a G5RV.
prcguy

Have a question for your guys, still running the G5RV dipole....

I have moved the ladder line all around here to keep it off the ground, ok right now I have it on a 20' piece of PVC pipe and the choke is a little lower on the pipe, and using a 50' piece of RG 213 coax, swr is running a 1.1, using a auto tuner....this is on bands 10-40m....

Ok 80m won't tune when the ladder line and coax like this....I even tried to add coax to the 50' and it still didn't help it any...


Back when the ladder line was hanging on my back porch, and I was using 120' of lmr 400uf coax on it, it did tune for 80m easy without any problems, as well as the other bands....

Why has the swr changed like this, is this normal ?...

 

[KD8NIV]

Good info, thanks......good to hear that's normal, still learning about these dipoles and how they work in different situations...I no here it has been a pain in the butt trying to get a antenna system that will work well in the yard...


I do have a good place to tie the LL off but would have to go under the power lines to do that....doing all this stuff like I have to keep from been under the lines, and it has been fun so far...so, I'll move the LL straight out to a pole and hope it works, can't let it drop straight down like people says in needs to be..

The ZS6BKW dipole, would work better in my situation I think so as well, will go to that soon, more than likely....would have more space for the LL to hang it up...

 

[prcguy]

I ran a G5RV at home for years and also had lightweight portable versions for camping. Then about 10yrs ago I discovered the ZS6BKW and its been my main house antenna ever since. I occasionally use one for camping and when there is no good place to run the ladder line I'll use an end fed half wave or offset center fed dipole. All work well depending on your surroundings and they are easy on your tuner or they may not even need a tuner.
prcguy

Good info, thanks......good to hear that's normal, still learning about these dipoles and how they work in different situations...I no here it has been a pain in the butt trying to get a antenna system that will work well in the yard...


I do have a good place to tie the LL off but would have to go under the power lines to do that....doing all this stuff like I have to keep from been under the lines, and it has been fun so far...so, I'll move the LL straight out to a pole and hope it works, can't let it drop straight down like people says in needs to be..

The ZS6BKW dipole, would work better in my situation I think so as well, will go to that soon, more than likely....would have more space for the LL to hang it up...

 

[KD8NIV]

The thing I don't like about the G5RV is the wires not been insulated for one, that's just me....and I don't like where mine is hanging, but it will have to do for now......have a lot of big trees on the hill side, but to get to them I have to go under the power lines, in which the coax would be well insulated if I did this, just a thought....I'm still looking for a place to move my LL to, to keep it up and away from all the metal I have here, and stay clear of the power lines....

I have heard all good things about the ZS6BKW dipole, and did lot of research on it too....

 

[KD8NIV]

Have a question...

This G5RV dipole, if I put it in a tree, and it touches some of the tree limbs it will cause the swr to be high ?
My friend who is also a ham operator is telling me it won't, I don't agree with this..


Here's what I'm looking at doing, have a tree on the hill which is around 60' high that has the tree limbs all cut off the one side, and the back side still has limbs on it, looking at putting my G5RV up in this tree in a Vert position, just curious if the limbs would have any affect on the swr if it touched or not..

 

[prcguy]

Yes, if the wires touch limbs it can change the SWR and degrade performance. But a G5RV has a terrible match on all bands except for 20m and since you need a tuner anyway it will usually work ok.

A G5RV has lots of lobes and nulls on the higher bands and if you hang it vertically it may have a null at the horizon and not work very well. Look up the radiation pattern of a G5RV then you can see what bands will have this problem.
prcguy

Have a question...

This G5RV dipole, if I put it in a tree, and it touches some of the tree limbs it will cause the swr to be high ?
My friend who is also a ham operator is telling me it won't, I don't agree with this..


Here's what I'm looking at doing, have a tree on the hill which is around 60' high that has the tree limbs all cut off the one side, and the back side still has limbs on it, looking at putting my G5RV up in this tree in a Vert position, just curious if the limbs would have any affect on the swr if it touched or not..

 

[KD8NIV]

Ok yeah kinda thought it would since there's no insulation on the wires......it does a pretty good job here, able to work the states, and into Europe some, and South America, and that's about it......the noise I get kills my receive here, usually have a S9 on it, most of the time on the G5RV....

May just go with the ZS6BKW soon, need to get me some ladder line, it be ok to splice into what's on it now ?..

I've been playing some with a ground plain I put up a few days ago, it's just 3' off the ground and using 6 ground radials on it, so far it seems to be doing ok, the noise ain't bad on it.....

 

[KE0GXN]

Here is a very good analysis on the G5RV showing 3D patterns for various bands. This should give you an idea where yours is working best. http://www.bvarc.org/pdf/g5rv_w5rh.pdf
prcguy

I just purchased an MFJ 1778 G5RV and did a G5RV site search and came up with this thread....

Many thanks for this link. Very informative!

 

[KD8NIV]

Hello guys, haven't been here for awhile, but here's a up date.....

Still running the G5RV dipole, and it's been working great here, only thing I ran into is I do have some RFI now in the shack, not sure how to get rid of it....I'm running 50' of RG 213 coax on it, and a 4" coax choke on it as well....have moved the ladder line and choke several times, but never noticed the RFI until I got this new computer tower and I use a USB adapter on it, it don't have windows in it like the lap top did......but while using the radio my pc freezes up, and it keeps you busy shutting it down and taking the USB plug out and plugging it back in......

What can I do to cure this problem ?...

 

[KD8NIV]

Something else we have been working on....

Have a friend who was talking to me about using this Imax 2k I have for HF use, so I hooked it all up like he said and it works really well on 10-40m bands.....later have plans on trying a small beam...

 

[KD8NIV]

Problem with my G5RV, hoping it's just the conditions but my Imax 2k has better receive on it than the G5RV does, it's been like this for a couple weeks now....not sure what's going on with it, this has never happened before, just curious if this is normal ?..

My Imax 2k, I can a S9 on someone and switch over to the G5RV dipole, and not even hear the person on it...

 

[kmh603]

I have the G5RV Jr. on a 10 ft mast on my 2nd story roof. The wires go down to both gutters and tied there. I have about 4 ft of of the 450 Ohm leader line on my roof and I get SWR 5 on all bands except 20 meters which is 1.1 SWR. Any ideas?

 

[prcguy]

To start with, a G5RV is a 20m antenna and has a lousy match every where else. A G5RV Jr is a 10m antenna and should have a reasonable match somewhere on 10m, otherwise it has a lousy match everywhere else. Some roof materials would interact and affect ladder line laying on it so that may be compounding the problem. Do you have the full supplied (tuned) length of ladder line and a 1:1 choke balun between the ladder line and the coax?
prcguy

I have the G5RV Jr. on a 10 ft mast on my 2nd story roof. The wires go down to both gutters and tied there. I have about 4 ft of of the 450 Ohm leader line on my roof and I get SWR 5 on all bands except 20 meters which is 1.1 SWR. Any ideas?

 

[wb6uqa]

If the gutter is metal you are making a short. Keep the center twin lead away from metal.

 

[kmh603]

No it's about 1 foot from the gutter tied off and I'm using a 10 ft PVC pipe mast and yes the ladder line is tuned and choked. I also put a T-4plus on the coax to reduce noise.

 

[KD8NIV]

Found a wet soaked PL connector on the G5RV was the problem, been raining here on and off for weeks.....I also moved the dang ladder line again, now it is coming straight down from the center connector, and a slight dip in it and hung the coax choke on the back porch, ladder line is all off the ground, and no RF in the shack anymore, lol, now this is weird, but it works....G5RV talks great like this, worked a guy in Venezuela, SA the other morning, lol....really don't see how it talks this good because of where the coax choke is, lol.....but will leave it here for now...