Tram discone question

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JDE100

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I am in installing a Tram discone on a block wall between lots. To be a good neighbor I would like to remove any of the lower radials that cross over fence. If I do remove 2 how much will this affect reception?
 

mmckenna

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I am in installing a Tram discone on a block wall between lots. To be a good neighbor I would like to remove any of the lower radials that cross over fence. If I do remove 2 how much will this affect reception?

Yes. It's going to probably make it directional.
 

Ubbe

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If I do remove 2 how much will this affect reception?
They are designed for the longest wavelenght you will receive, the lowest frequency. It is usually 80-100MHz on most discones. If you only wish to receive 118Mhz and upwards you can cut them in lenght. 60cm or 24 inches in length would match 118MHz and will have no ill effects on higher frequencies or if you only cut a couple of the radials and not all of them, but it will look nicer if you cut them all to the same lenght.

The 700MHz band and higher do not work so well with discones and the shorter you can make all radials, even the top horizontal ones, the better the higher frequencies will work. If you cut both lower and upper radials to half lenght it will work better in the high frequency bands but will loose some in the lower air band.

/Ubbe
 

JDE100

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They are designed for the longest wavelenght you will receive, the lowest frequency. It is usually 80-100MHz on most discones. If you only wish to receive 118Mhz and upwards you can cut them in lenght. 60cm or 24 inches in length would match 118MHz and will have no ill effects on higher frequencies or if you only cut a couple of the radials and not all of them, but it will look nicer if you cut them all to the same lenght.

The 700MHz band and higher do not work so well with discones and the shorter you can make all radials, even the top horizontal ones, the better the higher frequencies will work. If you cut both lower and upper radials to half lenght it will work better in the high frequency bands but will loose some in the lower air band.

/Ubbe
The one I have is below. So I could cut the lowers down to 24"? I only listed to VHF and higher.

1607615421926.png
 

Ubbe

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If you settle for full receive at 150MHz and up you can cut from 32" to 20" and the top horizontal from 10 1/2" to 7" and will improve 700MHz and up if you also cut those upper ones.

/Ubbe
 
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