[TowerTalk] Myantennas

[Daniel Danny Horvat]

-----Original Message-----
From: Richard (Rick) Karlquist [mailto:richard at karlquist.com] 
Sent: Saturday, November 21, 2015 7:05 AM
To: Daniel Danny Horvat; towertalk at contesting.com
Subject: Re: [TowerTalk] Myantennas



On 11/20/2015 6:31 PM, Daniel Danny Horvat wrote:

>
> BTW I own an old HP/Agilent 8711 network analyzer and would love to 
> here how would you measure insertion loss of 4:1 (200:50) TLT with any 
> network analyzer? Enlight me please.

Not with just "any network analyzer", like the 8711; you need a 4 port
network analyzer, such at the Agilent E5071C with 4 port option.
I've measured many baluns with one of those.  Gives common mode and
differential mode s parameters, with programmable Zo for each port.  Also
measures imbalance.  The Agilent software will walk you through the set up.


>>>Again, not impressed, I do not need 4 port, Agilent E5071C, $50,000 USD
(refurbished) analyzer to measure insertion loss. Imbalance of simple 4:1 as
well as 1:1 Baluns can be measured with much simpler methods and
instruments.

>
> Second, your proposal of better 4:1 BALUN for OCF antenna involving 4:1
> balanced transformer in cascade with current 1:1 BALUN is impractical,
given
> the fact that broadband 3-30MHz balanced transformer will always have more
> insertion loss than simple 4:1 transmission line transformer formed with
two
> separate 1:1 current BALUNS.

My homebrew broadband 1.8-54 MHz 9:1 transformer has very low insertion 
loss.  If it didn't, it wouldn't be able to handle 1.5 kW without over
heating.  Has worked for me for many years.

>>>My 9:1 TLT Balun with three 2.4" separate wound cores has less loss than
any 9:1 balanced transformer I tried to make. Mine can handle 1500W RTTY in
48 hours contest, yet that does not tell what is the insertion loss until it
is measured.

>>>73 Danny E73M



73

Rick N6RK


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