Hi Kerry,
Very nicely built set-up! The supply internals look great.
I started building the VNA and RF-IV adapter just over 10 years ago, and I was a bit naive.
Knowing what I know now, I too would have gone with a linear supply.
I will modify at some point, and post the results.
It was the largest home-built project I'd attempted at the time (and might still be!). I couldn't have done it without the help from everyone on the N2PK mailer. My father was around then, and even though he didn't know what it was, he loved seeing it being assembled, with the careful coax plumbing inside and all, so the VNA project is a whole nice memory for me.
________________________________
From:
[email protected] <
[email protected]> on behalf of Kerry via groups.io <planningpower@...>
Sent: 29 January 2024 02:24
To:
[email protected] <
[email protected]>
Subject: Re: [N2PK-VNA] RFIV vs bridge
G'day Shabaz.
I did some measurements a few days ago on a 10k metal-film leaded resistor; this topic energised me this morning to process the S11 file.
See attached.
It's clear that the RF I-V fixture does not do well at low frequencies; its function is to provide measurements of low and high impedances.
Mine works from 0.5 - 100 MHz.
I haven't used it for low impedances; I have a project that requires measurements down to milliohms so I might use it there.
When I built my N2PK, I built a separate linear power supply; I'm old-fashioned and I don't feel entirely comfortable with switching supplies, although I admit that they have improved greatly over the years.
Photos of my home-made "wall-wart" :) are attached.
Regards, Kerry VK2TIL.
