It is currently Sun Dec 17, 2017 3:34 pm

Click the link below to visit the site sponsor

The Ham Radio Shop




Post new topic Reply to topic  [ 12 posts ] 
 All band wire antenna. 
Advanced Member

Joined: Mon Mar 24, 2014 4:22 pm
Posts: 275
Location: Warrington
Feedback: 21 (100%)
Reply with quote
Post All band wire antenna.
Hi,
I currently negotiation a deal on some land to rent which is 300ft in length for a remote station.
I am looking for advice / suggestions on what to erect.
My thought was to go for a Carolina Windom 160 all band or one of the Hyendfed longwire antennas, although 160m doesn't seem to be an option.
I've tried one of the Carolina OCF before but struggled with keeping the vertical element up in the air.
I was thinking of maybe 3 Fibreglass poles at 40 ft ?

Any other suggestions or advice would be appreciated.

This will be a remote station so ideally the antenna needs to be tuned by the radios ATU.

Was looking at in of the Flex radios to remote and use the Maestro at home.

Thanks

Glenn


Wed Dec 06, 2017 7:51 pm
Profile Send private message

 All band wire antenna. 
Intermediate Member

Joined: Sat Jul 14, 2012 11:15 am
Posts: 89
Location: Waterlooville, Hampshire IO90LV
Feedback: 3 (100%)
Reply with quote
Post Re: All band wire antenna.
I have been running a double sized 204ft G5RV at 40ft which I have found to be a very good all round antenna. I am feeding the matching stub with about 80ft of RG213 and I find the internal ATU in my IC7600 will find a match on all bands in terms of what the PA is looking at!

If you want one antenna that will give good results from LF to HF then the double sized G5RV is worthy of consideration. It has a multi lobe pattern once you get higher in frequency and you do start to realise a little modest gain.

I wrote an article about it in Practical Wireless. If you email me direct (see qrz.com) I will send you a copy.

My personal preference would always be for a centre fed balanced antenna rather than an OCF or end fed. However, having said that, the off centre fed "Windom" if constructed correctly and using a 4:1 Guanella (current) balun does show some good swr figures on a number of bands.

If you are able to, it might be instructive to try both a centre fed system (such as the double sized G5RV) and then a Windom so you can compare the two.

73's Vince G3TKN Waterlooville, Hampshire.


Wed Dec 06, 2017 8:02 pm
Profile Send private message

 All band wire antenna. 
Advanced Member

Joined: Mon Mar 24, 2014 4:22 pm
Posts: 275
Location: Warrington
Feedback: 21 (100%)
Reply with quote
Post Re: All band wire antenna.
Hi Vince,
Thanks for the advice, the article would be much appreciated and I will email you shortly?
How did you support the G5RV at the centre to stop it drooping ?
I am sure there will be lots of trial and error but it's not has frustrating if you have the space to work with.
Thanks
Glenn


Wed Dec 06, 2017 8:23 pm
Profile Send private message

 All band wire antenna. 
Contributor 2017

Joined: Sat Mar 31, 2012 8:11 pm
Posts: 2371
Location: Markyate, St Albans, IO91ST
Feedback: 6 (100%)
Reply with quote
Post Re: All band wire antenna.
M1AQO wrote:
Hi Vince,
Thanks for the advice, the article would be much appreciated and I will email you shortly?
How did you support the G5RV at the centre to stop it drooping ?
I am sure there will be lots of trial and error but it's not has frustrating if you have the space to work with.
Thanks
Glenn


My antenna is a doublet which is about the same length of a G5RV and I've got a Spiderbeam fibreglass pole supporting the middle and the feeder runs down the pole cable tied to it, alloy scaffold poles are supporting each end of the doublet.

_________________
Image


Wed Dec 06, 2017 8:38 pm
Profile Send private message

 All band wire antenna. 
Advanced Member

Joined: Mon Mar 24, 2014 4:22 pm
Posts: 275
Location: Warrington
Feedback: 21 (100%)
Reply with quote
Post Re: All band wire antenna.
Thanks Paul,

That sounds like a plan with a non conductive pole for the centre.

I assume attaching the ribbon feeder to the pole doesn't affect the performance?

Is is the 200ft doublet you have ?

Glenn


Wed Dec 06, 2017 8:42 pm
Profile Send private message

 All band wire antenna. 
Contributor 2017

Joined: Sat Mar 31, 2012 8:11 pm
Posts: 2371
Location: Markyate, St Albans, IO91ST
Feedback: 6 (100%)
Reply with quote
Post Re: All band wire antenna.
Mine is only 100ft long, I have tried with the feeder in free air and strapped to the pole and can't notice any difference, there is a slight difference in matching when it gets wet, but nothing the balanced matching unit in the shack can't handle.

_________________
Image


Wed Dec 06, 2017 8:50 pm
Profile Send private message

 All band wire antenna. 
Advanced Member

Joined: Mon Mar 24, 2014 4:22 pm
Posts: 275
Location: Warrington
Feedback: 21 (100%)
Reply with quote
Post Re: All band wire antenna.
Thanks for the info Paul.

Vince,

Why did you choose the G5RV over a Doublet ?

Thanks

Glenn


Wed Dec 06, 2017 9:10 pm
Profile Send private message

 All band wire antenna. 
Contributor 2017

Joined: Sat Mar 31, 2012 8:11 pm
Posts: 2371
Location: Markyate, St Albans, IO91ST
Feedback: 6 (100%)
Reply with quote
Post Re: All band wire antenna.
I think I can answer that Glenn, a G5RV is a doublet, it's the open wire feeder plus half the antenna length when calculated offers a match on certain bands. The ZS6BKW antenna is a G5RV variant that offers a better match on more bands than the G5RV, but it won't cover 160M like a double size G5RV would, there are plenty of measurement on the internet for it.

I just like running the feeder back to the shack where I've got control over the matching with a decent home made matching unit, not so easy if you are remotely feeding though.

_________________
Image


Wed Dec 06, 2017 9:24 pm
Profile Send private message

 All band wire antenna. 
Advanced Member

Joined: Mon Mar 24, 2014 4:22 pm
Posts: 275
Location: Warrington
Feedback: 21 (100%)
Reply with quote
Post Re: All band wire antenna.
All understood Vince,

So I think my best choice will be either a full or double size G5RV,

Looking at the EA Antenna version, they offer 300 and 450
ohm. I assume 450 offers less loss ?

On the assumption that the antenna is mounted at 40ft and the ribbon length
is 17m would you suggest that it trails in the floor or raise it off the ground ?

The radio ATU should handle the matching.

Glenn


Wed Dec 06, 2017 10:28 pm
Profile Send private message

 All band wire antenna. 
Advanced Member

Joined: Mon Mar 24, 2014 4:22 pm
Posts: 275
Location: Warrington
Feedback: 21 (100%)
Reply with quote
Post Re: All band wire antenna.
All understood Vince,

So I think my best choice will be either a full or double size G5RV,

Looking at the EA Antenna version, they offer 300 and 450
ohm. I assume 450 offers less loss ?

On the assumption that the antenna is mounted at 40ft and the ribbon length
is 17m would you suggest that it trails in the floor or raise it off the ground ?

The radio ATU should handle the matching.

Glenn


Wed Dec 06, 2017 10:38 pm
Profile Send private message

 All band wire antenna. 
Intermediate Member

Joined: Sat Jul 14, 2012 11:15 am
Posts: 89
Location: Waterlooville, Hampshire IO90LV
Feedback: 3 (100%)
Reply with quote
Post Re: All band wire antenna.
I fully agree with Paul's (G4LNA) comments about the "ZS6BKW". If one is not bothered about top band, then the "ZS6BKW" offers a better match on more bands than the 102ft G5RV. I have used the ZS6BKW (full info on internet) and feeding coax to the matching stub (as per ZS6BKW's article) resulted in a low SWR on 40, 20, 17, 12 and 10m. No ATU was needed.

I ran some 80ft of coax (RG213/UR67) to the matching stub and found the aerial worked quite well on 80m provided I used an ATU at the shack end. Now it is very important to understand that doing this does NOT reduce the mismatched line loss on the coax at 80m, but since the frequency is low, the mismatched line loss was not too great. The use of the ATU at the shack end enabled the PA stage to see a resistive 50 ohm load and deliver full power.

I have always been surprised that we see lots of ready made up 102ft G5RV's being sold by various outlets and on the internet, but hardly any made up "ZS6BKW's" which offer a good match on 5 bands as I have listed above.

Prof. Brian Austen (G0GSF/ZS6BKW) wrote a computer programme back in the 1980's to optimise the G5RV (the article was published in Radcom) and I feel that he has not had the credit that he deserves. More people still talk about the "G5RV" than the "ZS6BKW"! I do feel the double sized 204ft G5RV is a very worthwhile antenna as it does give a "near" resistive match (at the end of the matching stub) on 160, 80, 40, 30, 17 and 15m. I have been using one for nearly two years and certainly on 160m to 30m it has proved a good all round antenna. However, I am only able to accommodate it's length due to my next door neighbour allowing me to run it across to a tree in the corner of their garden.

If one wants maximum efficiency, then the ladder line (or open wire feed) should be brought right into the shack and tuned via a properly balanced ATU. The antenna is then a "doublet".

73's Vince G3TKN


Sat Dec 09, 2017 5:47 pm
Profile Send private message

 All band wire antenna. 
Advanced Member

Joined: Mon Dec 28, 2009 8:46 pm
Posts: 162
Location: pencoed, south glam (j35 m4)
Feedback: 13 (100%)
Reply with quote
Post Re: All band wire antenna.
I use a Zs6BKW here , home made with open wire feeders, to get it in I folded it like a cobra and it works very well. They are for fore sale via a Scottish station (ebay) and plenty on sale in the states.
The internal atu on the rig tunes it from 3.5 to 50 megs no problem, but via the 4 to 1 balun as described in the rsgb mag. I also wrote an article condemning the g5rv, as on sale commercially, it is a good doublet but like any doublet it needs tuning on any band except 14/ 24.9 megs. In my opinion, here, it is the most miss sold antenna commercially available.

don gw3rvg


Sun Dec 10, 2017 12:14 pm
Profile Send private message
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 12 posts ] 


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB © phpBB Group.
Designed by Vjacheslav Trushkin for Free Forums/DivisionCore.