Topband: Two 2:1 transformers to choose from!!

[Charlie Cunningham]

Well, that FO0AAA KAZ terminated loop has pretty good gain as terminated RX
loops go, so I wouldn't expect the system to be noise starved, but the gain
opf that loop is of the order of -30 dBi at 160, so a preamp is in order.

Charlie, K4OTV

-----Original Message-----
From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Tom W8JI
Sent: Thursday, August 22, 2013 9:41 PM
To: 'topband'
Subject: Re: Topband: Two 2:1 transformers to choose from!!

>
> Since  you wound both transformers, why not try them both, and see if you
> can measure any difference? I' guessing you won't see much!
>


Unless the antenna system is starved for background noise, or the element is

in an end-fire phased array, it makes very little difference. The only real 
effect of mismatch is signal and noise from the antenna drop equally. 
Outside of a low sensitivity array, or an array that is phased end-fire, 
until background drops with 10 dB of RX system noise floor, or preamp noise 
floor, it really doesn't matter.

Two turns for 75 ohms is plenty for decent 100 kHz to 30 MHz performance.

Now if you hook up a Sky Buddy, it's a different problem.  :)

Tom 

_________________
Topband Reflector