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Author Topic: Low-cost ½ λ Dipole for HF QRP rigs  (Read 1683 times)

Offline vu2nan

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Low-cost ½ λ Dipole for HF QRP rigs
« on: December 27, 2014, 03:42:49 UTC »
This is the antenna I strung up ages ago, when I had hombrewed my vacuum tube transmitter and couldn't wait till I had acquired some coax!

http://nandustips.blogspot.in/2011/02/low-cost-dipole-antenna-for-hf-qrp-rigs.html

73,

Nandu.

Offline GM0LVI

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Re: Low-cost ½ λ Dipole for HF QRP rigs
« Reply #1 on: December 27, 2014, 10:29:17 UTC »
I like it Nandu. Simple,light and cheap!  :D
Dave

Offline PG4I

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Re: Low-cost ½ λ Dipole for HF QRP rigs
« Reply #2 on: December 29, 2014, 09:38:18 UTC »
another secret tip: when you use twin lead electricity appliance wire (the wire which plugs into your 110/220 V sockets), you impedance will be near 50 Ohms symmetric. You only need a 1:1 balun at the end of the wire.  ;)
Joop - PG4I/QRP

Offline KC8AON

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Re: Low-cost ½ λ Dipole for HF QRP rigs
« Reply #3 on: December 31, 2014, 12:55:02 UTC »
another secret tip: when you use twin lead electricity appliance wire (the wire which plugs into your 110/220 V sockets), you impedance will be near 50 Ohms symmetric. You only need a 1:1 balun at the end of the wire.  ;)

The impedance on the wire you are speaking of would calculate out to around 105 ohms, but still only a 2:1 swr thus a 2:1 balun or transformer would be needed.

Offline vu2nan

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Re: Low-cost ½ λ Dipole for HF QRP rigs
« Reply #4 on: March 05, 2015, 11:28:39 UTC »
I like it Nandu. Simple,light and cheap!  :D
Thanks, OM Dave!

73,

Nandu.

Offline vu2nan

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Re: Low-cost ½ λ Dipole for HF QRP rigs
« Reply #5 on: March 05, 2015, 11:39:12 UTC »
another secret tip: when you use twin lead electricity appliance wire (the wire which plugs into your 110/220 V sockets), you impedance will be near 50 Ohms symmetric. You only need a 1:1 balun at the end of the wire.  ;)

The impedance on the wire you are speaking of would calculate out to around 105 ohms, but still only a 2:1 swr thus a 2:1 balun or transformer would be needed.

Hi OM Joop & OM Richard,

No problem since I've used the antenna with rigs having pi tank output.

73,

Nandu.