QRP Club

QRP Station => Antennas => Topic started by: vu2nan on December 27, 2014, 03:42:49 UTC

Title: Low-cost ½ λ Dipole for HF QRP rigs
Post by: vu2nan 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 (http://nandustips.blogspot.in/2011/02/low-cost-dipole-antenna-for-hf-qrp-rigs.html)

73,

Nandu.
Title: Re: Low-cost ½ λ Dipole for HF QRP rigs
Post by: GM0LVI on December 27, 2014, 10:29:17 UTC: I like it Nandu. Simple,light and cheap! :D
Title: Re: Low-cost ½ λ Dipole for HF QRP rigs
Post by: PG4I 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. ;)
Title: Re: Low-cost ½ λ Dipole for HF QRP rigs
Post by: KC8AON on December 31, 2014, 12:55:02 UTC: Quote from: PG4I 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. ;)

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.
Title: Re: Low-cost ½ λ Dipole for HF QRP rigs
Post by: vu2nan on March 05, 2015, 11:28:39 UTC: Quote from: GM0LVI on December 27, 2014, 10:29:17 UTC
I like it Nandu. Simple,light and cheap! :D
Thanks, OM Dave!

73,

Nandu.
Title: Re: Low-cost ½ λ Dipole for HF QRP rigs
Post by: vu2nan on March 05, 2015, 11:39:12 UTC: Quote from: KC8AON on December 31, 2014, 12:55:02 UTC
Quote from: PG4I 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. ;)

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.