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 Shorting a doublet to make it an T antenna 
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Post Shorting a doublet to make it an T antenna
Does anybody sell a shorting switch, or have plans so I can build one myself?

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Was M6NTA, then 2E0NTA now M0XAL.


Wed Jun 04, 2014 8:45 am
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 Shorting a doublet to make it an T antenna 
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Joined: Thu Jul 23, 2009 3:09 pm
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Location: Cleveleys, Blackpool, Lancashire. LOC IO83LV
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Post Re: Shorting a doublet to make it an T antenna
I have a homebrew balanced tuner (double roller coaster type) into which I built a relay to short the feeder at the antenna terminal. Saves messing about undoing the feeder connections etc. The relay also grounds the unused antenna terminal when the feeders are strapped. Controlled by a push button switch on the front panel with a red led to remind me!
73 de Ken G3RFH


Wed Jun 04, 2014 10:18 am
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 Shorting a doublet to make it an T antenna 
Silent Key

Joined: Fri May 22, 2009 1:23 pm
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Post Re: Shorting a doublet to make it an T antenna
I'm a cheapskate - I terminate the incoming ladderline at two "banana" sockets; then use leads from the tuner, terminated in banana plugs, to patch it into the configuration I need.

Steve G3TXQ


Wed Jun 04, 2014 10:30 am
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 Shorting a doublet to make it an T antenna 
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Location: Tamworth Staffordshire IO92EP
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Post Re: Shorting a doublet to make it an T antenna
G3TXQ wrote:
I'm a cheapskate - I terminate the incoming ladderline at two "banana" sockets; then use leads from the tuner, terminated in banana plugs, to patch it into the configuration I need.

Steve G3TXQ


Now why did I not think of that. I can do this as the ladder line comes right into the shack and I have banana sockets on the back of the tuner.

Soldering iron at the ready.!! Cheers Steve.

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Wed Jun 04, 2014 2:37 pm
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 Shorting a doublet to make it an T antenna 
Silent Key

Joined: Fri May 22, 2009 1:23 pm
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Location: Northampton IO92ME
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Post Re: Shorting a doublet to make it an T antenna
I fixed a plastic box to the inside shack wall where the ladderline comes through the wall, and mounted two sockets on the box. I used phono sockets which are a perfect fit for the standard banana plug. Cosmetically it's nice because you never get to see any ladderline in the shack.

Two flying leads fitted with banana plugs come from the balanced output of the tuner up to the box and are plugged in when I need balanced (doublet) operation. When I want "T" operation there's a single lead from one of the tuner unbalanced SO239 outputs which splits at the far end to two short leads with banana plugs.

So swapping mode involves swapping over the banana plug leads and changing the tuner switch position.

Hope that makes sense :scratch:

Steve G3TXQ


Wed Jun 04, 2014 2:50 pm
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