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Author Topic: Building your own RF spliters  (Read 194 times)

Offline ChrisSmolinski

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Building your own RF spliters
« on: November 08, 2020, 1501 UTC »
Two of my recent RF projects, a 2-1 and a 3-1 splitter for HF and down. Wound on FT50-75 cores.

I use 1 pint "paint cans" for many of my RF projects, the lid provides a good surface for connectors and deadbug construction, testing is easy, then put it on the can for RF shielding when you're done.

First up, a 2-1 splitter based on this design, with a different resistor value: http://www.dxing.info/equipment/rolling_your_own_bryant.dx

Here's a nanoVNA plot of one of the outputs vs the input, mag(S21), the red line. Resistive load on the other output port. Not terrible, but not exactly close to what you'd expect, too much loss on the higher frequencies:

Next, a 3-1 splitter. This time, I just wound four identical windings, about a dozen turns each, no attempt to get fancy and match impedances or anything.

And the nanoVNA plot. Resistive loads on the other output ports. I think it's better  :)

« Last Edit: November 08, 2020, 1601 UTC by ChrisSmolinski »
Chris Smolinski
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Offline RobRich

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Re: Building your own RF spliters
« Reply #1 on: November 24, 2020, 0641 UTC »
Like the project, and thanks for the VNA plots. 8)

Admittedly, recently I took the lazie... err, slacker approach to the issue for HF signal splitting to multiple receivers. I bought an used A/V distribution amp. Probably going to have to poke at it to better limit EMI/RFI and perhaps decrease the active gain a little, though. Maybe when I get around to hooking up the various receivers, which could be sometime between in a few minutes and possibly never. :slack:
« Last Edit: November 24, 2020, 0659 UTC by RobRich »
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