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Hot Fusion
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Home made vertical for 45 metres
I've finished constructing a vertical for use 'around' 7MHz, and in case any of you wish to have a go at this but don't really know how to start, I've documented my efforts on a web page.
The page isn't finished really, but there's enough information there to get you started.
Oh - on the page I mention it's for 7MHz. You know what I mean. 
Yer 'tiz:
http://myweb.tiscali.co.uk/hotfusion/40m.htm
Last edited by Hot Fusion, 12/Jan/2009, 7:57 pm
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Andy - 26FB107
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11/Jan/2009, 7:16 pm
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Hot Fusion
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Re: Home made vertical for 45 metres
I haven't transmitted on it yet and I'm plaqued by interference (as I keep winging on about) but this type of antenna works well mounted on the ground - it uses the radials buried in the earth as its ground plane. This is normal format for the lower frequencies.
Apparently the angle of radiation is fairly low, meaning local-ish contacts may not be so good, but long range stuff is received well.
As for appearance, I do need a photo for the page, but basically it looks exactly like a common CB dipole - only the knowledgable would notice the slight modifications.
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Andy - 26FB107
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11/Jan/2009, 8:03 pm
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26fb99
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Re: Home made vertical for 45 metres
nice touches dude.i think a lesson we both can pass on to other homebrewers is that in the "real world" cheap key components are not easily obtainable and so as long as we firstly get the "funtion" correct using free stuff we can eventually enhance the "form".
dont suppose youve found anything for mobile(static) 45 use?
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yaesu FT857d,rmkl500,wilson5000,a99 (thats a real satchel of cack)/2element pubical quad(the BBq).split charger aux battery system.170a truck battery,mfj 941 versatune2
100percent mobile station
laters peeps 73s
Brent 26 Fox Bravo 99
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15/Jan/2009, 1:26 pm
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Hot Fusion
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Re: Home made vertical for 45 metres
Mobile use?
Funny you should mention that...
I am collecting the bits together almost as I type. It looks as if the antenna will be about 3 metres long, (obvioulsly only for static mobile!) with a centre loading coil.
I'm a bit concerned as to whether the car will suffice as a ground plane, but I'll post details and results here when I get something together.
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Andy - 26FB107
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16/Jan/2009, 8:02 pm
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Hot Fusion
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Re: Home made vertical for 45 metres
I've got a photo of this antenna for those interested. It's not a good one, bit it does show its GP27 origins.
It tuned in lovely - I had to remove about 3 or 4 turns from the loading coil, just about visible a couple of feet above the old bracket, but I still consider that pretty close.
The SWR goes down almost to 1:1, I suppose 1.1:1 would be more accurate - there is hardly any movement of the 'reflected' meter at all, and that is as measured right at the base of the antenna without feeder losses faking a low SWR. I do like an antenna that is natively a good match.
As for performance, time will tell, but I seem to be hearing a fair bit of activity, including 'local' UK stations 200 - 300 miles away when the prop. allows.
Basically I'm very pleased.
Last edited by Hot Fusion, 18/Feb/2009, 8:57 pm
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Andy - 26FB107
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18/Feb/2009, 8:56 pm
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mikefox whiskey
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Re: Home made vertical for 45 metres
Hi Andy, hope you are well, I had a look at your antenna page, well done, it was interesting to read and I think you enjoyed building the 40m vertical, I wonder have you made many contacts with it yet? and how does it perform?
--- Patrick - MFW / 68 FB750
kenwood TS870s - Astatic 1104c Microphone - 54 meter long doublet - Multiband Delta Loop.
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19/Feb/2009, 8:47 pm
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Hot Fusion
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Re: Home made vertical for 45 metres
Hi Pat.
I've not been in operation on this band very long as I only very recently acquired a means to transmit on it. (Even though the TX drifts like heck!)
The antenna does seem to work well though, and when stations are about they tend to boom in pretty strong - I hear you pretty well when the prop's running in that direction.
I should really add some more buried radials which would improve efficiency in theory, but I'll leave it as it is for now and get an impression of how it works over a period of time.
unfortunately I have to be careful operating from home, and keep any transmissions few and fairly far between - too many busy-bodies about in this village!
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Andy - 26FB107
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19/Feb/2009, 9:34 pm
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sks1966
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Re: Home made vertical for 45 metres
Now then Gents.
A question re the antenna, Ive made one of these before and it worked great but that was ten years ago.
Now what I want to ask is, if the antenna was not changed i.e the original coil not removed and the antenna was not seperated with the broom handle and the coil wound directly onto the alluminium with pvc coated wire would the anteena still see a good swr on both bands.
I ask this question because a friend purchased a 4 band vertical off ebay which is not seperated where the coils are wound.
It covers 40-20-11-10
It cost £95 plus £15 p&p
Its food for thought lads as a new silver rod only costs £20 ish
VC7
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28/Mar/2009, 11:10 pm
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Hot Fusion
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Re: Home made vertical for 45 metres
It would have to be separated at the coils, it just may not look like it.
Also, there should be no metal near the coil as this would spoil the inductance.
The idea you suggest wouldn't work as the pole would simply short the loading coil.
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Andy - 26 FB107
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29/Mar/2009, 10:34 am
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