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That is 0.75pf in parallel with 10MΩ resistor. Like a scope probe but lower capacitance. Not sure why if you are going to the trouble to build that why you couldn't go with a higher resistance and

I wouldn't think so. It's *sort* of like a spectrum analyzer - except it's got a few kHz measurement bandwidth, and if you're scanning 200-620, you've got steps every 4 MHz. The odds of you actually

That 0.75pF is 4KΩ at 50MHz, way down from 10MΩ.... 73, Don N2VGU

No? ?The Nano looks at the amplitude and phase of the signal it generates. You might see some minor amplitude variations of a strong external signal, but the Nano would nave no idea what frequency

The NANOVNAs are not suited for this application. A spectrum analyzer is. Take a visit to the following site: https://www.tinysa.org/wiki/ Dave - W?LEV -- *Dave - W?LEV* *Just Let Darwin Work*

Can I connect an antenna to ch1 and expect to see any signals? I did a scan, 200MHz to 620MHz of a TV antenna and had no trace. Is the signal just to small? Would a 20 db amp be enough to put it on

The specs say 0.75 pf and 10MΩ. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

If you look at the typical pi-network configuration of these vintage transmitters, there is nothing for the final plate blocking capacitor to work against. Therefore, it will never charge to the DC

I'm not so sure - if you're building a 3kV, 0.5 A supply (1.5 kW DC power) then you'd be putting in something that can suck up half an amp for at least long enough to trigger the overcurrent

Those chokes were rated at 125 ma or 300 ma at the most. If the plate blocking capacitor were to short, they would burn out before the primary fuse blew. Whatever the function is supposed to be, it

Thanks for the info. Luckily I figured out the capicator value and was able to derive the frequencies of the trap. Also the Nano VNA in Smith format will work. I probably will post Mosley info on the

I should have added that a dead or alive function using the vna as a troubleshooting aid is a reasonable application. Assume the probe is essentially ideal as far as the circuit under test is

Short link to that Amazon cable assembly would be the URL to get to Amazon then add /dp/B07YH9NNDQ I always use the smile.amazon since I donate to a good cause. -- 73 de Phil KE3FL

Thinking out loud, it's a unidirectional device, which maybe useful on port 2 in some way, but not useful on port 1 in any way that I can think of. Seems more appropriate for a scope, SA, or RF

I build one of my own a few years back for trouble shooting. You hold it near the oscillator, you hold it near the amp, you hold it near thedriver, you hold it near the final amp.? In a few seconds

This probe is just a capacitor input coupled FET source follower with a voltage regulator to run the FET. Input capacitance loading in in 10-15 pF range. Over a limited freq range it provides a high

Hi Clif Please let me know how you get on with it Maybe I can use it with my TS2000 ?thanks Dave 2E0DMB

Nobody said anything about calibrating it. It's a probe looking for signals with some measure of safety. Once found, then if needed, calibration could be done. This a troubleshooting tool not a lab

I'm not sure that I agree with this. For typical simple use of a VNA with the ports of a 2-port DUT, sure, but if you're wanting for example to examine standing waves in a multi-pole filter or a DUT

Active RF probing with the VNA is useful. https://www.keysight.com/us/en/assets/7018-02190/technical-overviews/5990-4148.pdf However, you would have to figure out how to apply this probe to a cal and