[ARC5] Why an UNUN?

[J. Forster]

Where did the 12 Ohms, resistive, come from? A manual? The value of a
dummy load? Where?

-John

===========


>
> 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.
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>