[Amps] bi-directional coupler question

m.ford k1ern at direcway.com
Fri Nov 18 22:02:18 EST 2005

----- Original Message ----- 
From: "Dan Sawyer" <dansawyer at earthlink.net>
To: "m.ford" <k1ern at direcway.com>
Cc: <amps at contesting.com>
Sent: Friday, November 18, 2005 9:23 PM
Subject: Re: [Amps] bi-directional coupler question

> Thank you. The coupler I have is too high frequency for my current 
> needs. I am interested in a 1 to 100 MHz bi-directional coupler. However 
> bi-directional couplers are much less common then uni-directional ones.  
> There appear to be uni-directional couplers in the HF and VHF range 
> available.
> Are couplers 'reversible, that is can the output be applied to the 
> input? The purpose if this would be to make a bi-directional coupler 
> from 2 uni-directional couplers.  Is this practical?
Yes, the mainline can be fed in either direction. For a single port 10db
coupler the coupled port will be 10db down. If you feed it backwards
the coupled port will now be isolated. If you take two of them and turn
one around,  then connect them in series you have a bi-directional coupler
that is also known as a dual-directional coupler because the coupled ports
are equal. If you are interested in looking at forward and reflected power
levels over a wide range then you can use different coupling values for
each, say 30db for forward and 10db for reflected. The preferred method
is to use a dual directional and pad the ports accordingly.

> Thanks again - Dan
My pleasure.

Mike k1ern


More information about the Amps mailing list