Correct inside angle for homebrew dipole

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108EH002
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Correct inside angle for homebrew dipole

Post by 108EH002 »

What is the preferred inside angle of an inverted v dipole,and is there a precise distance inbetween the two ends of a 1/4 wave homebrew dipole,or is it just down to luck when you consider what it is constructed out of/where it is situated ?

I only ask as I am going to make a dipole out of 2 lengths of copper pipe instead of wire/other metals that I have used in the past like the plaster corner beads I use at present.I am going to put the pipe dipole on the internal wall down each side of the last A-frame against the gable end,so will be at the pitch of the outside roof,and before any says "just try it"..........I am just about to find out ;) thanks in advance.
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ch25
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Re: Correct inside angle for homebrew dipole

Post by ch25 »

1. Distance between elements 10mm is fine.
2. Putting antenna against the wall is bad idea.
3. Angle should be 90-120 degrees.
Chris
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108EH002
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Re: Correct inside angle for homebrew dipole

Post by 108EH002 »

Ok cheers Chris,had put it 6ft off gable.

The S.w.r is 1.3 on 26.965
1.0 on 27.500
1.1 on 27.991.25


I included a rf choke of 6 turns on a 4 inch plastic pipe just to make sure,each length of 15 mm copper pipe was 102 inches or 8 1/2 ft long,with the live and earth held in place with jubilee clips,before being insulated with tape and held inplace (but not touching anything ) as it was supported with fishing line :thumbup:
Plenty are talking worldwide on 27.555 usb,
Some are too far up their own @rse to admit it,
Many happen to know otherwise dx-ing test free,
Showing a complete lack of respect for the law.

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ch25
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Re: Correct inside angle for homebrew dipole

Post by ch25 »

Too good to be true. Do you trust your meter?
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108EH002
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Re: Correct inside angle for homebrew dipole

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Swr checked with 2 different radios with built in digital meters that gave identical results,but maybe these are upto 10-20% out.
The sizes used are the suggested required for length for each leg,and the suggested diamater of homebrew rf choke,with these sizes I have achieved 1.5 -2 MHz workable bandwidth in the past,with good enough results for me.Maybe it shouldn't work in theory to you Chris,but in reality it can work different eh.
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Many happen to know otherwise dx-ing test free,
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ch25
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Re: Correct inside angle for homebrew dipole

Post by ch25 »

I asked about meter, because I didn't find CB meter stand alone or built in, showing the truth out from the box :)
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Re: Correct inside angle for homebrew dipole

Post by MrWeetabix »

ch25 wrote: 17 Nov 2018, 21:30 I asked about meter, because I didn't find CB meter stand alone or built in, showing the truth out from the box :)
so what do you use and how do you know that it is accurate?
26TM175. OP: Craig. QTH: Gateshead IO94EW. Also 163TM175 when mobile in Wales 8)

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ch25
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Re: Correct inside angle for homebrew dipole

Post by ch25 »

Connect 100 Ohm resistor instead of antenna (proper wattage ofc) and check SWR reading. Must be 2. 75 ohm should give 1.5. If not, calibrate (if possible) or trash your meter.
Wattage readings can be verified with DMM, dummy load and simple RF probe.
Chris
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Re: Correct inside angle for homebrew dipole

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Managed 20 miles on fm to an op in his house,so tuned enough for me ;) :thumbup:
Plenty are talking worldwide on 27.555 usb,
Some are too far up their own @rse to admit it,
Many happen to know otherwise dx-ing test free,
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ch25
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Re: Correct inside angle for homebrew dipole

Post by ch25 »

Means nothing, but I'm glad you are satisfied :)
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Re: Correct inside angle for homebrew dipole

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No,it actually means I managed 20 miles :)
Plenty are talking worldwide on 27.555 usb,
Some are too far up their own @rse to admit it,
Many happen to know otherwise dx-ing test free,
Showing a complete lack of respect for the law.

27.555 Usb
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