[ARC5] Why an UNUN?

[Mike Hanz]

Pick a number...any number...between 0.1 and 13.  <huge grin>  If you'll 
go to http://aafradio.org/docs/Aircraft_Antenna_Design.html you'll see 
why it's difficult to specify a lower limit for a transmitter designed 
to go in a number of aircraft, from small fighters to large bombers.  
Their example is a 47 foot antenna resonant at 5MHz, operating at 3MHz - 
the radiation resistance is 1.9 ohms. The graph at the bottom is perhaps 
more useful in visualizing the problem.

73,
-  Mike

On 10/24/2012 10:58 PM, Neil wrote:
>> The 13 seems a bit high. Is there a lower limit given also? I don't have
>> that manual to hand.
> I've seen a figure of 5 ohms, but I can't recall where.
> Most likely on this very forum.