In article . com,
wrote:

On Apr 19, 7:38 pm Telamon wrote: 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...

-- Telamon
----------------------------------------------------------------

Please review the information at:
http://www.microwaves101.com/encyclo..._splitters.cfm

And note that a resistive splitter has:

"Resistive power dividers are easy to understand, can be made very
compact, and are naturally wideband, working down to zero frequency
(DC). Their down side is that a two-way resistive splitter suffers 3
dB of real resistive loss, as opposed to a lossless splitter like a
hybrid. Accounting for the 3 dB real loss and the 3 dB power split,
the net power transfer loss you will observe from the input to one of
the two outputs is 6.04 dB for a two-way resistive splitter. (Thanks,
Dr. BKS, for helping us clarify that point!)"

I own a Mini Circuits ZFSC-2-. It has a measured insertion loss of
less then 3.5dB for 100KHz through 30MHz

Another strength of tranformer based hybrids/power splitters is the
greater isolation between power out ports.

The Mini circuits ZFSC-2-1is rated for: 5 MHz 25dB isolation
midband (~450MHz) 20dB isolation 500MHz 20 isolation These are
minimum not typ[ical.

My unit has been measued to have better then 25dB isolation between
the power out ports from ~250KHz to above 30MHz. The isolation start
to creep up below 250KHZ reaching a minimum of ~21dB at 100KHz. Below
100KHz the loss starts increasing and by 10KHZ the loss is just over
9dB and the isolation is down to just less then 15dB.

The "roll your own splitter" page gives some real world loss and
isolation data:
http://www.dxing.info/equipment/roll...own_bryant.pdf

MiniCircuits isloation PDF
http://www.minicircuits.com/appnote/pwr2-4.pdf

MiniCircuits hybrid/power splitter PDF
http://www.minicircuits.com/appnote/psc2-2.pdf

Quoting again frm the article on resistive splitters: "To put it
simply, the resistive splitter has double the dBs compared to a
lossless splitter's insertion loss. Thus a two-way resistive splitter
transfers -6.04 dB power to each arm, a three-way splitter transfers
-9.44 dB, a four-way transfers -12.08 db, etc."

And: "The isolation of a resistive splitter is equal to its insertion
loss."

I hope that we can all agree that 3.5 dB loss is much better then 6dB
loss and that 20dB isolation is better then 12dB isolation. I ued the
wort case bad specs from minicircuits for loss and isolation.

In the microwave world resitive splitters are the rule. In HF/VHF/UFH
transformer splitters appear to dominate.

Sorry for the dublicate posting under two threads. I feel this is a
very important concept and wanted to make sure my position is clear.

Some of the information you posted above is wrong. Please read my post
at the top.

It does not matter if the passive splitter is resistive or a coupled
transformer type the power divides in half otherwise you will violate
the laws of conservation.

The transformer type will provide some isolation between the ports above
what the resistive splitter will provide but that's about it.

Sorry that just the way it is as you don't get something for nothing in
this world.

--
Telamon
Ventura, California