Re: LF: Antenna relays - bifilar coil

[Markus Vester <markusvester@aol.com>]

Another approach: Make a LF loading coil with bifilar wire. For HF in differential mode the coil will just be a large common-mode choke. You can either connect relay at the bottom end where LF voltage is much lower, or alternatively use an HF-balun or diplexer there.

 

You could also use that coil together with a bifilar vertical, and use the differential mode to feed power up to a quadrocopter which holds the antenna aloft. 

 

73, Markus (DF6NM)

-----Ursprüngliche Mitteilung----- 
Von: Chris Wilson <chris@chriswilson.tv>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Do, 19 Nov 2015 1:02 pm
Betreff: LF: Antenna relays

19 November 2015 

 

 

I am currently running a bottom strapped windowed ladder line feeder to 

my  horizontal  quad  loop  as  the  vertical for LF, the loop as the 

capacitive  top hat. It means I am unable to use it for HF though. I am 

wondering if I might add a remote switched relay at the bottom of the 

ladder line, so it has two states. One connects my co ax feeder to the 

ladder  line  with  the  bottom strapped together. the other opens the 

strap and connects the 2 legs to a balun and then my co as feed line. 

 

Given  the voltages involved at LF, what sort of relay would I need to 

be looking at? Thanks. 

 

 

 

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Best regards, 

 Chris  2E0ILY                           mailto:chris@chriswilson.tv