[SADXA] DX SPOT 40m YF9CDL 7005 kHz 2310z

[W7EXG (Bill)]

Good Luck,

Bill W7EXG

-----Original Message-----
From: sadxa-bounces at mailman.qth.net [mailto:sadxa-bounces at mailman.qth.net]
On Behalf Of W7EXG (Bill)
Sent: Friday, December 21, 2018 12:51 AM
To: 'Southern AZ DX Association E-Mail Reflector'
Subject: [SADXA] Output Impedance of Baluns

These comments were made by Bill Davis W7EXG at the 12-20-18 SADXA meeting.


OUTPUT impedance of Baluns is not alike.  

For example, the output impedance of a 1:1 Balun [from Balun Design], is
Inductive with input terminated on 50 or 75 ohms. 

The output impedance of a 1.5:1 balun (75/50 ohm Balun) (from Balun Design)
is capacitive with input terminated on 50 ohms.  

Thus, for a fixed rotatable dipole element length, the resonant frequency of
the dipole using a 1:1 Balun (75 ohm Coax) will be substantially different
than for this same dipole element length with the 75/50 ohm balun (50 ohm
Coax).  

BOTTOM LINE: Output impedance of Baluns is important, yet this important
characteristic is typically not specified.

73's
Bill W7EXG 

______________________________________________________________
SADXA Website http://www.sadxa.org

SADXA mailing list
Home: http://mailman.qth.net/mailman/listinfo/sadxa
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:SADXA at mailman.qth.net

This list hosted by: http://www.qsl.net
You can support qsl.net: http://www.qsl.net/donate.html