It is currently Mon Sep 24, 2018 9:53 pm

Click the link below to visit the site sponsor

The Ham Radio Shop




Post new topic Reply to topic  [ 12 posts ] 
 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Windom antenna ?
Is there any evidence to suggest a windom antenna antenna will work better in a straight line rather than in say a sloping v shape with the ends at say 20 feet and the centre on a non metallic pole attached to the house around 5/6 feet above gutter height so say 25 feet in total ?

Although I have a fair sized rear garden it's long in length rather than width and with the windom being off centre fed then obviously the coax run would be a lot longer if I had to run the coax half way down the garden to reach the feed on the shorter leg.

Sloping v shape as above sound okay ? Have bought a line isolator for the windom how far would you recommend siting this below where the coax enters the windom ie. anything to be gained by running it say 6 feet down the coax to achieve any Carolina windom style vertical radiation gains or just run it say a foot down from the Feedpoint and block out any coax radiation full stop ?!

The non metallic pole I would be using to mount the centre feed off the windom and the line isolator again around 6 feet above the gutter level would be made off a heavy duty plastic pipe and held securely by two TK brackets could I mount an HF vertical ( Cushcraft r6000 ) from this or would a fibreglass mounting pole be better to hold it all ?

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Sun Apr 15, 2018 9:42 am
Profile Send private message

 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Re: Windom antenna ?
Okay from further reading it would appear to forget the fibreglass mounting pole for my situation due to it flexing so much etc. So okay if I use an ally pole what's best to isolate the feedpoint enclosure and also the line isolator from the mast ?

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Sun Apr 15, 2018 10:12 am
Profile Send private message

 Windom antenna ? 
Advanced Member
User avatar

Joined: Fri Sep 14, 2012 5:32 pm
Posts: 3585
Location: Salisbury, Wiltshire
Feedback: 16 (100%)
Reply with quote
Post Re: Windom antenna ?
You say made of a heavy duty plastic pipe. You then refer to a fibreglass pole.

I think you are talking about using a 25ft fibreglass pole mounted on T K brackets. I further think that you have read something that says the fibreglass will flex too much.

Now, I think you've read an article which refers to the fishing poles...yes, too flexible.

But if you are planning to use a 2" heavy duty fibreglass pole, feel free...that won't be too flexible. Just think.of a windsurf mast. (carbon now but GF in my day)

D

_________________
David. G4YVM


Sun Apr 15, 2018 2:21 pm
Profile Send private message

 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Re: Windom antenna ?
Thanks David appreciate that. Sorry if I was unclear with my question . The support pole I was talking about would be about 10feet in total and again held by T&K brackets with about 6 foot above gutter level and would support the centre feed for the windom and also hold the HF vertical.

There is a metal support pole there just now which I could use but again not sure if the centre feed / coax and line isolator would be affected by the close proximity off this metal mast ? Could obviously run the coax at an angle away from the metal mast with the line isolator attached further along on say the wood facia board but the centre feed enclosure box off the windom would still be need to be secured to the pole itself ?

Would this be okay or get myself a 10 foot 2"" thick walled fibreglass pole to hold both ? If so where would I obtain such a thing ?

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Sun Apr 15, 2018 4:03 pm
Profile Send private message

 Windom antenna ? 
Contributor 2018
User avatar

Joined: Fri Feb 20, 2009 11:43 pm
Posts: 1910
Location: Mwyljyn Moddey, Ellan Vannin. IO74ti
Feedback: 33 (100%)
Reply with quote
Post Re: Windom antenna ?
Engineered composites http://www.engineered-composites.co.uk in Wrexham do all sorts of GRP poles. They will post.

However if that's no good contact a local scaffolding supplier, you can get GRP scaffolding poles now.

Finally, be careful using GRP with TK brackets or similar U bolt type fixings. It's easy to over tighten them and crack the composite. It'll look fine until it comes crashing down in the wind.

_________________
Andy - GD1MIP
Using decidedly average equipment from Mwyljyn Moddey, Ellan Vannin or IO74ti to you and I.


Sun Apr 15, 2018 10:31 pm
Profile Send private message

 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Re: Windom antenna ?
Thanks Andy great info appreciate that.john

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Sun Apr 15, 2018 10:56 pm
Profile Send private message

 Windom antenna ? 
Advanced Member
User avatar

Joined: Wed Jan 27, 2010 8:56 pm
Posts: 2935
Location: IO92mg Northampton... Boz Wellox!
Feedback: 2 (100%)
Reply with quote
Post Re: Windom antenna ?
Just nosing on your QRZ page John and you have a wire dipole in the picture so what's wrong with that one unless it's a single band dipole?

Just thinking you could gain height just by runnng the end of the wire up to the gable which is what I've done with my bit of wire this morning, here I could go a bit higher still by mounting a pole at the gable but having nearly shit myself when the wind reached 10 mph that will be the next session and wearing bicycle clips.

Disappointingly the only contact so far with the added 8 ft of height at one end has been LX2LA on 40 using 200w :blush: however on 20 listening to OM3TWM I could actually hear some of the W's and the VY station he worked lunchtime, when I say hear it was more lip reading.

Cheers, Dave.


Mon Apr 16, 2018 1:24 pm
Profile Send private message

 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Re: Windom antenna ?
Okay cheers Dave that's great, yes your right picture was off an old Carolina windom that I had up which to be fair worked fine until the wires snapped and the innards off the line isolator broke up. !!

Anyway with this new windom style ( not Carolina windom style with vertical radiating length off coax )I wanted to mount in the style suggested. thanks If I was to use mount the balun enclosure on the metal pole but insulate it wonder if this would still effect it's tuning ?

The other idea is to mount another pole further along the roof in the same style but use a foot feet off wood above the pole to mount the balun as on this support pole this is all it would never.no further antennas planned to be mounted on top off it other than this balun.

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Mon Apr 16, 2018 2:32 pm
Profile Send private message

 Windom antenna ? 
Advanced Member
User avatar

Joined: Wed Jan 27, 2010 8:56 pm
Posts: 2935
Location: IO92mg Northampton... Boz Wellox!
Feedback: 2 (100%)
Reply with quote
Post Re: Windom antenna ?
I think I get the gist of what you want to do John and if that metal pole is simply supporting the end of the Windom and you're worried about detuning the antenna you could swap the metal pole for a length of wooden dowel called a broom handle, they're normally hardwood so last quite a while before failing spectacularly years later.

If I've got the wrong end of the stick you could use the same broom handle to support the nearest end of the Windom and that metal pole shouldn't screw up the feed point too badly with the antenna running horizontally at right angles over the top.

Cheers, Dave.


Mon Apr 16, 2018 4:06 pm
Profile Send private message

 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Re: Windom antenna ?
Okay cheers no not the end off the windom the balun in the centre !! No problem what I will do is get a crossover plate and clamp it to the metal pole and mount a length off plastic piping horizontal and attach the balun enclosure to this.. hopefully problem solved. !!

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Mon Apr 16, 2018 5:02 pm
Profile Send private message

 Windom antenna ? 
Contributor 2018

Joined: Wed Nov 17, 2010 3:34 pm
Posts: 1694
Location: Fife in scotland
Feedback: 72 (100%)
Reply with quote
Post Re: Windom antenna ?
GD1MIP wrote:
Engineered composites http://www.engineered-composites.co.uk in Wrexham do all sorts of GRP poles. They will post.

However if that's no good contact a local scaffolding supplier, you can get GRP scaffolding poles now.

Finally, be careful using GRP with TK brackets or similar U bolt type fixings. It's easy to over tighten them and crack the composite. It'll look fine until it comes crashing down in the wind.


Sorry mate did mean to get back to you to say had a quote from the above company for 1 x scaffolding type pole in GRP and it's working out around £150 delivered ... Gulp !

As I have mentioned I am going to use a crossover pole mount to have a length off horizontal 1.5" plastic pipe around a metre in length to secure the balun enclosure. Just wondering regrards tightening the bolts against this plastic pipe, better to use some rubber strip between the tube and unbolt to prevent cracking ?

_________________
Icom IC7300 / Kenwood TR751e
5/8 wave 10mtr vertical / 80-10mtr OCF dipole.
Behringer xm8500 mic ( IC7300 ) Datong ASP ( TR751e )
Ameritron als600x s/s linear

QRV on 10mtrs ssb.


Tue Apr 17, 2018 11:39 am
Profile Send private message

 Windom antenna ? 
Novice Member
User avatar

Joined: Tue Feb 20, 2018 1:40 pm
Posts: 21
Location: Darwen, Lancashire
Feedback: 0 (0%)
Reply with quote
Post Re: Windom antenna ?
I bought some rubber lined munsen rings (ebay) to clamp a fibreglass tube (sandpiper) for the far end of my windom.


Thu Apr 19, 2018 9:53 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.