[ARC5] Why an UNUN?

[D C _Mac_ Macdonald]

I gather, then, that the ARC-5 and SCR-274 transmitters 
are designed to work into an impedance around 12 Ohms? 
And therefore, addition of the 4:1 Un-Un will allow the 
command sets to load properly into the usual dipole? 
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* k2gkk at hotmail.com * 
* Oklahoma City, OK * 
* USAF & FAA (Ret.) * 
* * * * * * * * * * * 
 
 
> From: brianclarke01 at optusnet.com.au
> To: arc5 at ix.netcom.com
> Date: Thu, 25 Oct 2012 08:22:30 +1100
> CC: arc5 at mailman.qth.net
> Subject: Re: [ARC5] Why an UNUN?
> 
> And a third reason, Dave,
> 
> You can fit an appropriate Unun inside the BC-442 or equivalent.
> 
> And the turns ratio of the unun will be 2:1 because you require 24 V across 50 Ohm to deliver 12 W. Using a small ferite core can allow this unun to cover most of the ham bands that Command sets can work - 160, 80 and 40. So, no need for external components or any per set modifications.
> 
> 73 de Brian, VK2GCE.
> 
> > David Stinson <arc5 at ix.netcom.com> wrote:
> > 
> > 
> > Found a WiFi hot spot for my laptop. :-)
> > 
> > Couple of reasons for using the series cap
> > and broadband UNUN:
> > 
> > Assuming a resonant antenna, does not require 
> > one to build and/or add an external tuning network.
> > More important: It's simple, easy and cheap.