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Marconi wrote:

You've misunderstood me Marconi. Where the SO239 is located on the A99 is approx 10 or 12 inches from the tuning section (the length of the short piece of coax inside). This arrangement has a disadvantage over a standard half wave GP if you want to mount radials. The reason being: you would have to include the length of the mounting tube in your quarter wave electrical length to create your 108 inch radial otherwise you will have 132 inch radials.
To bypass this problem the easy solution would be to remove the SO239 completely and solder your coax direct to the feed point aswell as soldering a bridge from the top of the tube to your outer braid at the feed point. This would cut out the losses associated with feed point sockets, remove the mounting tube from the electrical length of your radials and ensure your radials are located where they should be electrically and in proximity to the radiator where they would be on a half wave GP.

<blockquote data-quote="nav2010" data-source="post: 347196" data-attributes="member: 14757">Marconi wrote:You&#039;ve misunderstood me Marconi. Where the SO239 is located on the A99 is approx 10 or 12 inches from the tuning section (the length of the short piece of coax inside). This arrangement has a disadvantage over a standard half wave GP if you want to mount radials. The reason being: you would have to include the length of the mounting tube in your quarter wave electrical length to create your 108 inch radial otherwise you will have 132 inch radials.To bypass this problem the easy solution would be to remove the SO239 completely and solder your coax direct to the feed point aswell as soldering a bridge from the top of the tube to your outer braid at the feed point. This would cut out the losses associated with feed point sockets, remove the mounting tube from the electrical length of your radials and ensure your radials are located where they should be electrically and in proximity to the radiator where they would be on a half wave GP.</blockquote>

[QUOTE="nav2010, post: 347196, member: 14757"] [B]Marconi wrote:[/B] You've misunderstood me Marconi. Where the SO239 is located on the A99 is approx 10 or 12 inches from the tuning section (the length of the short piece of coax inside). This arrangement has a disadvantage over a standard half wave GP if you want to mount radials. The reason being: you would have to include the length of the mounting tube in your quarter wave electrical length to create your 108 inch radial otherwise you will have 132 inch radials. To bypass this problem the easy solution would be to remove the SO239 completely and solder your coax direct to the feed point aswell as soldering a bridge from the top of the tube to your outer braid at the feed point. This would cut out the losses associated with feed point sockets, remove the mounting tube from the electrical length of your radials and ensure your radials are located where they should be electrically and in proximity to the radiator where they would be on a half wave GP. [/QUOTE]

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