question about balun? - RF Cafe Forums

The original RF Cafe Forums were shut down in late 2012 due to maintenance issues - primarily having to spend time purging garbage posts from the board. At some point I might start the RF Cafe Forums again if the phpBB software gets better at filtering spam.

Below are the old forum threads, including responses to the original posts.

-- Amateur Radio
-- Anecdotes, Gripes & Humor
-- Antennas
-- CAE, CAD, & Software
-- Circuits & Components
-- Employment & Interviews

-- Miscellany
-- Swap Shop
-- Systems
-- Test & Measurement
-- Webmaster

Tiany
Post subject: question about balun? Posted: Sat Sep 12, 2009 10:39 pm

Lieutenant

Joined: Sun Jun 07, 2009 9:14 am
Posts: 4
1.Who know the balun(T2&T3) in following picture is
1:4 or 1:9?

2.If the balun(T2&T3) is 1:4,then what is the different between this balun and another balun(T4&T5) as following picture.
.
Thanks.

Top

Jose Arrina
Post subject: Re: question about balun?Posted: Wed Sep 16, 2009 12:18 pm

Lieutenant

Joined: Thu Mar 30, 2006 9:01 am
Posts: 4
Hi Tiany:

Based on the cascode transistor configuration, I'd say those are coaxial implementations of 3dB hybrid couplers for the input and output. Length differences for input/output are for bandwidth/tuning purposes.

Sound reasonable?

_________________
... Jose' Arrina

Top

Tiany
Post subject: Re: question about balun?Posted: Thu Sep 17, 2009 8:09 am

Lieutenant

Joined: Sun Jun 07, 2009 9:14 am
Posts: 4
Thank Jose Arrina.
Do you know the impedance transform of the balun is 1:4 or 1:9?

Posted 11/12/2012