Hi all, do any members know the measurements needed to build a delta-loop antenna for the eleven meter band that would be able to achieve low s w r measurements and that would be able to take approx fifty watts if needed to boost the tx signal ? Please help and Thank-you,
-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
Delta-Loop Antenna Self Build
- Thread starter barefootindian
- Start date
Here is what you need to know:
11 Meter Loop Antenna
You can make it a square, round, or even a triangle. It can be vertical or horizontal too. Should tune the same so long as the length of the antenna wire is the same and you make the matching section correctly.
Hope that helps some . . .
11 Meter Loop Antenna
You can make it a square, round, or even a triangle. It can be vertical or horizontal too. Should tune the same so long as the length of the antenna wire is the same and you make the matching section correctly.
Hope that helps some . . .
Deita Loop Self Build.
Thanks Robb for getting back to me so quickly. I recently heard that the Delta- Loop was a good antenna and I thought it might be a big bucks outlay but in fact it could be put together quite cheaply. Thanks for the link to cb online. I'll just follow the instructions and see how it turns out. Thanks again.
Thanks Robb for getting back to me so quickly. I recently heard that the Delta- Loop was a good antenna and I thought it might be a big bucks outlay but in fact it could be put together quite cheaply. Thanks for the link to cb online. I'll just follow the instructions and see how it turns out. Thanks again.
The general formula for a loop is 1005/F(MHz). Loops are designed for the lowest frequency of operation and then provide even and odd harmonic operation from there. When using transmission line for matching it will normally be designed to operate on the design frequency.
Using 26.965 MHz for channel 1 the formula is 1005/26.965 = about 37 ft, 3.25". That is for bare copper wire. It will be about 5% less when using insulated wire. A VSWR meter/bridge or an antenna analyzer is helpful for fine tuning at this point. (Note: Use a different frequency if operating elsewhere of course. I'm using 26.965 which is the normal CB Channel 1 frequency for these examples.)
The general size for different geometric shapes are:
Delta (3 sides): 12' 5" per side, about 10' 9" in height for vertical.
Sqr (4 sides): 9' 4" per side, about 13' 2" diagonal
Hex (6 sides): 6' 2.5" per side, about 12'8" diagonal
Oct (8 sides): 4' 8" per side, about 12' 2" diagonal
The 75 ohm cable is 246/F(MHz) x Velocity Factor (VF) of the cable used.
The cable is usually RG-59/U or RG-6/U. The VF for RG-59/U is usually .82 (82%), and for RG-6/U it is usually .81 (81%).
The cable length is then (246/26.965) x .66 for RG59/U = 9.12 x .66 = 6.02 ft or (246/26.965) x .81 for RG-6/U cable 9.12 x .81 = 7.38 ft.
This should get you in the ballpark.
73,
Mike
Using 26.965 MHz for channel 1 the formula is 1005/26.965 = about 37 ft, 3.25". That is for bare copper wire. It will be about 5% less when using insulated wire. A VSWR meter/bridge or an antenna analyzer is helpful for fine tuning at this point. (Note: Use a different frequency if operating elsewhere of course. I'm using 26.965 which is the normal CB Channel 1 frequency for these examples.)
The general size for different geometric shapes are:
Delta (3 sides): 12' 5" per side, about 10' 9" in height for vertical.
Sqr (4 sides): 9' 4" per side, about 13' 2" diagonal
Hex (6 sides): 6' 2.5" per side, about 12'8" diagonal
Oct (8 sides): 4' 8" per side, about 12' 2" diagonal
The 75 ohm cable is 246/F(MHz) x Velocity Factor (VF) of the cable used.
The cable is usually RG-59/U or RG-6/U. The VF for RG-59/U is usually .82 (82%), and for RG-6/U it is usually .81 (81%).
The cable length is then (246/26.965) x .66 for RG59/U = 9.12 x .66 = 6.02 ft or (246/26.965) x .81 for RG-6/U cable 9.12 x .81 = 7.38 ft.
This should get you in the ballpark.
73,
Mike
Delta Loop Antenna Self Build
Hi Mike, Thanks for the very detailed info. I wasn't too sure wheather or not to use bare or insulated wire but you answered that question for me. I was thinking of going for a three sided loop and had thought about needing approx twenty one feet ten inches on three sides but now I see that those figures were way off. I'll have a good read of your post again and then decide which style that I'll go for. Thanks again 73's Sean.
Hi Mike, Thanks for the very detailed info. I wasn't too sure wheather or not to use bare or insulated wire but you answered that question for me. I was thinking of going for a three sided loop and had thought about needing approx twenty one feet ten inches on three sides but now I see that those figures were way off. I'll have a good read of your post again and then decide which style that I'll go for. Thanks again 73's Sean.
BJ radionut
Supporting Member and 6m addict
Hi all..... Well I finally got the DELTA-LOOP put together yesterday Sunday the 20th and tried a few call outs. the usual bunch of guys weren't on so I tried a few DX shout outs but as I didn't have the antenna very high (about 14 feet or so) I got no contacts at all. I heard loads of european stations though.Next up is to get the delta-loop up higher and get some extra coax to get it futher up the hill and then I reckon it'll be cookin. I had great fun doing it up tho. I was thinkin of doubling up on the measurements to make an antenna twice the size. Would that work or would it be a misadventure? Just wonderin.....
You can give it some more height with some more coax length. You don't need to put it on the top of the hill; but higher in the air would be better.
Did you check it with a SWR meter to see if it was tuned correctly?
The length of that loop is already tuned correctly for your radio as it is right now. That loop is exactly 1 wave length @ the 11 meter/CB band. If you made the loop twice the size it is now, then it would no longer be tuned for the 11 meter/CB band. Put it twice as high instead. Now, that is a plan . . .
Last edited:
Hi Robb and hi m42duster, iust callin in for a quick comment. I checked the SWR readings and it read 1.1 on channel 1 and 1.3 on channel 40. I'm happy with that for sure so with more height it should do the trick. I dont know how to post a picture yet but I'll ask a friend who is more technicly capeable to explain how to do it and then I'll post one of the antenna in a higher position.At the moment am workin late most evenings and some late nights so I wont be able to call in so often. 73's for the moment and Thanks again for your help.