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See here:?

On Sat, Aug 29, 2020 at 07:52 AM, Erik Kaashoek wrote:

See here:?

Thanks Erik,
? ?The two tinySA tracking generator set-up is totally understandable now.? I noticed one spelling err ...

? ?The dynamic range in this setup is limited due to the reverse leakage true the mixers

Should be 'leakage thru' .

? - Herb

On Sat, Aug 29, 2020 at 07:52 AM, Erik Kaashoek wrote:

? ?See here:?

? ?...The dynamic range in this setup is limited due to the reverse leakage thru the mixers ..

==============================================
Erik,
? ?I compared the two tinySA tracking generator set-up against a NanoVNA-H4 s21 measurement.? I see what you mean about limited dynamic range.? Far better to own a NanoVNA and a tinySA and let each do what it does best.? When you only own a hammer everything looks like a nail.

? ?30MHz LPF, NanoVNA-H4? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ??30MHz LPF, two tinySA tracking generator set-up
? ?? ? ?

? In a pinch if you own two tinySA's and no NanoVNA (unlikely with the low cost of each device) then the two tinySA tracking generator setup may suffice for a NanoVNA s21 measurement - if you aware of the dynamic range limitations.??



- Herb

A fascinating comparison.

However, ?there are apparent differences in the results, in that the sa/tracking generator does not show the endstop attenuation at -40db, despite the scale (presumably 10db per div) going to -70db.

It brings back memories of when I first played with a home-made spectrum analyser in the early 90’s (0-100mhz, 60db dynamic range, display on a scope). I made a bridge and noise generator to align filters etc.

interestingly, I got it out recently, as I had originally modded it to have an extra rbw filter of 1khz but it was useless because the first swept oscillator ( ramp generator into a variac diode) had too much jitter, but it was because the original designer had made a circuit error. I would like to get it out again and compare it with the Tinysa.

Anyway, I have several nanovna devices, as well as an old Deepace KC901s.

Steve L. G7PSZ

The real reason why you would used the tinySA with a tracking generator is to measure frequency translation devices such as a mixer as this can not be done using a nanoVNA.
I added an example to the wiki

On Sun, Aug 30, 2020 at 01:25 AM, Erik Kaashoek wrote:

The real reason why you would used the tinySA with a tracking generator is to measure frequency translation devices such as a mixer as this can not be done using a nanoVNA.
I added an example to the wiki

Holy moly, a three tinySA set-up. Who'd of thought :)

- Herb

On Sun, Aug 30, 2020 at 07:22 AM, hwalker wrote:

Holy moly, a three tinySA set-up

You guys have those nice HP or even better signal generators, I have none, so I must use some cheap tinySA for my experiments