Thread: splitter ?
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Old April 26th 05, 07:09 AM
Telamon
 
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In article ,
Tebojockey wrote:

On Wed, 20 Apr 2005 02:38:40 GMT, Telamon
wrote:

In article ,
Tebojockey wrote:

On Mon, 18 Apr 2005 00:12:32 GMT, Drifter wrote:

- Hide quoted text - - Show quoted text -
************************

thanks to one and all for some great info. i need to study on
this. i found an old article in the july/04, NASWA Journal. get
my facts together here, and move to there. would be fun to build
when i find the time. thanks again... Drifter...


Now that the dust has settled a little bit and the belligerents
are hopefully being triaged.....


Not a chance! I have to give you a hard time.


You don't. One-upmanship has no place here.


You have no sense of humor.


Please read the spec sheets on the prospective splitter you intend
on using or, if rolling your own, look at the design. Many
splitters claim to have "only" a 3 or 5 dB loss, but that's only
"best case." Often times, the loss will vary greatly across the
operating range of the splitter (and sometimes the impedance!).
For HF and MF, the losses are usually not too bad.


Snip

There are passive and there are active splitters.

Passive can be transformer or resistive it does not matter. If the
splitter is one port to two ports then the power is going to divided
in half between the two output ports. It is that simple. Half the
power is 3dB and half the voltage is 6 dB. That's all there is to
it.

Active splitters can be anything because you can have any amount of
amplification to to make up for the division in power.

Same story with one to four ports where the power out is 1/4 the
power in. Same story with any other division splitter.

Now if you force me to I WILL resort to an analogy where you have
this bushel of apples you want to divide in half and...




You are arguing points that I did not even discuss.


That happens on Usenet when more than 2 people participate in a
discussion.

What you are describing is the standard "Wilkinson" splitter or
combiner. We could also discuss 90 degree splitters and other
variants, but that would be beyond the ascope of what I was trying to
impart to the person I was trying to help.


Sorry I messed up your message.

Your assertion that they may be active or passive is correct. Loss
implies a passive splitter (be it resistive or reactive), while the
other part of my dissertation (as far as raising the noise floor,
etc.) implies an active splitter. Perhaps it was not clear to you,
but perhaps the person who it was posted for understood what I was
saying.

I should have also given him information on port to port isolation as
well as the effect upon his 3d order intercept points that active
splitters can cause, but I didn't feel it would benefit him.

My intent was to be as layman as possible to assist the person asking
the question.


Yeah, it's a balancing act all right.

--
Telamon
Ventura, California