|
On 01/04/2025 22:39, kox.jeroen via groups.io wrote:
Hello,Sounds more like a job for a NanoVNA! David -- SatSignal Software - Quality software for you Web: Email: davidtaylor@... BlueSky: @gm8arv.bsky.social, Twitter: @gm8arv |
|
Yes, the TinySA is a spectrum analyzer. The NanoVNA is a network analyzer. The NanoVNA can be used to measure impedances of coax, the rate of loss of coax over a frequency range, SWR. It has a TDR function. It can be used to measure values (resistance and reactance, impedance) of inductors, capacitors, resistors. It can be used to measure the response curves of filters. It can be used to measure the gain and frequency response of preamps, amplifiers, etc. The TinySA is not meant to do any of these things. The TinySA may give you a glimmer of loss of coax, but it won't be as accurate as the NanoVNA. It certainly doesn't have a TDR function. But it can tell you if a circuit is oscillating, or if it has spurious signals. It can tell if there are outputs at harmonics of an amplifier. It can tell you what RF signals are present in an area. I have a couple microwave circuits that use copper pipe caps as bandpass filters. The circuits are frequency multipliers. The TinySA is very useful to make sure I have the pipe cap filters tuned to the correct harmonic of the input, and used to peak the signal at that frequency. Zack W9SZ On Wed, Apr 2, 2025 at 1:26?AM David J Taylor via <davidtaylor=[email protected]> wrote: On 01/04/2025 22:39, kox.jeroen via wrote: |
|
On Tue, Apr 1, 2025 at 11:25 PM, David J Taylor wrote:
I would like to see how many dB loss I have in You can see the loss at a particular frequency... but AFAIK, you can't do a sweep from 470 MHz to 600 MHz, and plot a graph.
Because, AFAIK... Tiny SA does not have a tracking gen. (You need one to sweep.)
?
You have to take several (many, if you like) measurements, at different frequencies, and then use Excel (or other software) to plot a graph of Attenuation vs. Frequency. (or plot by hand.)
Since you are missing data at frequencies not measured, you can't infer that that there isn't something funky happening at those frequencies.
But if you think there is, just measure at, and around that particular frequency.
Did it this way many times.
?
?
? |
|
On Wed, Apr 2, 2025 at 01:21 AM, Zack Widup wrote:
TinySA may give you a glimmer of loss of coax I don't see why.
If I measure power level x, with a SA
And then if I insert a 10 dB attenuator.... I usually see a 10 dB loss... maybe a little more due to connector losses, etc.
A matched length of coax properly terminated at each end, measured at a particular frequency, within the bandwidth specified for that coax....
That should be a reasonable approximation to an attenuator. |
David J Taylor