Dear Erik,

There have been a lot of postings on the various nanovna groups, saa2 in particular, about static discharge damage, and adding an esd diode diodes across each input. The?ESD101B102ELE6327XTMA1, seems popular, (and cheap) with a bilateral breakdown voltage of 5.5v.

Would this give any protection from input overload to the Tinysa? It is a tiny device and cannot dissipate much power but the very low capacitance is not so important for a spectrum analyser and maybe a physically bigger one, but with a 5v (or lower) breakdown voltage would be better.

Steve L

For those who are using the TinySA as a bandscope and/or panadapter: how are you connecting it to your antenna without having to constantly plug and re-plug when you want to transmit or receive?

Are you using a directional coupler or an antenna switch?

Things I have used are either end (retracted) of an ink pen, my fingernail, an orange wood stick, either end of a pencil, the tip of a key, the guitar pick stylus that came with the unit, the handle of a fingernail clipper, and a BST126 plastic pry bar with the pointy end filed to be more blunt. There may have been others but that's all that come to mind.

73

-Jim
NU0C

On Thu, 04 Feb 2021 17:08:49 -0800
"Jim Allyn - N7JA" <jim@...> wrote:

I use a variety of items as styluses, depending upon what's closest to me, but it's usually one of those shown below.? On the left is a stylus I bought at Dollar Tree for, you guessed it, a dollar.? Besides being a stylus, it has a pen in it, plus a red pointer LED and? white flashlight LED.? Unfortunately, they tend to come apart unless you crimp it to make it tighter, or tape them together, or whatever.

In the middle is another stylus I bought at Dollar Tree, again, one buck.? No lights, but it does have a pen in it.

On the right is a mechanical pencil, of which I use the eraser as a stylus.? I probably got it either at Dollar Tree, or possibly at Office Depot.? If I got it at Dollar Tree, it was, of course, a dollar.? If I got it at Office Depot, I probably bought a package of several of them for a few dollars.? I kind of like this one because the eraser is small enough that I'm not likely to hit several buttons at once, or hit the wrong button by mistake.

In any case, I usually buy several - or a bunch - of them at once and scatter them all over the house, so there's usually one within sight no matter where in the house I happen to be.

One would hope, buy you have to remember the old saying: "Nothing can be made foolproof because fools are so ingenious".

73

-Jim
NU0C

On Thu, 04 Feb 2021 11:47:58 -0800
"Erik Kaashoek" <erik@...> wrote:

We added a link to the wiki in the box in the hope people would read the specification:
--
------------------------------------------
For more info on the tinySA go to

Here's a better view. :)

73

-Jim
NU0C


On Thu, 4 Feb 2021 20:19:26 +0100
"Carsten Bormann" <cabocabo@...> wrote:

On 2021-02-04, at 19:16, John Cunliffe W7ZQ <n2nep@...> wrote:

Anyone who would assume the input not to be 50 ohms better not play with RF test equipment and go back playing in his sand castle…

Yeah, but at least HP caters to the denizens of the sand castle.
(The max power warning label is the yellow thing on the lower side of the N connector.)

Grü?e, Carsten

On Thu, Feb 4, 2021 at 04:45 PM, waltcates wrote:

I have a DSA705 on the way.

Good for you!? Spectrum analyzers are wonderful toys to have.? I have a Siglent SSA3021X spectrum analyzer here, which I really like. I also have a Siglent SDS1104X-E oscilloscope that will do FFTs so it can be used as a spectrum analyzer, too.? It's only a 100 MHz scope, but since it samples at 1 GHz, it will play spectrum analyzer quite a bit higher than that.? (Not really convenient to use as a spectrum analyzer, but usable.)? I think the highest I have ever displayed on it is about 250 MHz.? I have been looking out for an old HP or Tek spectrum analyzer that will go up to 20 GHz or thereabouts, but with the virus going around, all the hamfests have been canceled, so that will probably have to wait.? And of course I have 3 tinySAs here!

I use a variety of items as styluses, depending upon what's closest to me, but it's usually one of those shown below.? On the left is a stylus I bought at Dollar Tree for, you guessed it, a dollar.? Besides being a stylus, it has a pen in it, plus a red pointer LED and? white flashlight LED.? Unfortunately, they tend to come apart unless you crimp it to make it tighter, or tape them together, or whatever.

In the middle is another stylus I bought at Dollar Tree, again, one buck.? No lights, but it does have a pen in it.

On the right is a mechanical pencil, of which I use the eraser as a stylus.? I probably got it either at Dollar Tree, or possibly at Office Depot.? If I got it at Dollar Tree, it was, of course, a dollar.? If I got it at Office Depot, I probably bought a package of several of them for a few dollars.? I kind of like this one because the eraser is small enough that I'm not likely to hit several buttons at once, or hit the wrong button by mistake.

In any case, I usually buy several - or a bunch - of them at once and scatter them all over the house, so there's usually one within sight no matter where in the house I happen to be.

On Thu, Feb 4, 2021 at 01:36 PM, waltcates wrote:

Is there any way to get the RBW down to 200Hz with a center freq of 3.9MHz and a scan width of 8KHz?

Keep it simple please.

Not on the TinySA.?

But if you want a low cost solution use an SDRplay RSP1A and the free Spectrum Analyzer program that was written for it.? A little over $100 USD

Roger

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On Thu, Feb 4, 2021 at 03:39 PM, <whyme505898@...> wrote:

Hello, I do not believe I have a clone, I opened the SA up, and it had the version of 3.0,not 4.0,OK. Here is what I have, during the calibration, my SA will not make it past the 4th configuration I believe. Here is a -pic of the issue, does any one have a fix for this, as I tried a few things with the settings,with no luck. I cannot believe this has a issue, had this for a month, first time I am trying to learn this as I am aligning a CB radio,( and trying to figure the tinySA out on what to use and how? ) Any idas would be very appreciated. Thank you,Mark..

I see in your photo that you have a cable attached to both ports and assume you are connecting the two ports together for the self test. ? Have you checked the cable to make sure that it is OK??

If you have changed any of the level settings you can set them back to factory defaults by doing a clearconfig 1234?command in console mode.? You can use the a terminal app like the free Tera Term? or the TinySA app to send this command.?

Did your TinySA ever pass all the self-tests?? Have you used it anywhere near your CB when you were transmitting?

Roger

No. Resolution bandwidth is determined in the main chip, and it only has a certain number of RBWs available.? The filters are implemented in firmware internal to the chip.? I think 2.7 kHz, or 3 kHz, something like that, is the lowest RBW available.

Hello, I do not believe I have a clone, I opened the SA up, and it had the version of 3.0,not 4.0,OK. Here is what I have, during the calibration, my SA will not make it past the 4th configuration I believe. Here is a -pic of the issue, does any one have a fix for this, as I tried a few things with the settings,with no luck. I cannot believe this has a issue, had this for a month, first time I am trying to learn this as I am aligning a CB radio,( and trying to figure the tinySA out on what to use and how? ) Any idas would be very appreciated. Thank you,Mark..

Wow!? What a response!? Now, it's "decisions, decisions"? lol

Thanks everyone!

Rick Hendricks
KE0GB

I'm not aware of any way to go that far down in RBW (but I would be delighted to be proven wrong!), not to mention the waveform on the display will have a flat top that makes finding the exact peak a judgement call.

When I need very small RBW I just use an SDR (even a cheap $25 one like an RTL-SDR dongle), along with a program like HDSDR, which will get you RBW values down to 0.1 Hz.

Sharing some results I obtained using a GPS-disciplined oscillator (GPSDO; 1 ppb accuracy) to measure the output frequency accuracy for the TinySA. I used the heterodyne method: i.e. set the GPSDO to exactly 1000 Hz lower frequency than the (unmodulated) TinySA output, then use an AM mode receiver/software to measure the frequency of the audio tone produced, and compare it to the theoretical 1000 Hz value.

As one would expect, the ppm error was consistent, I assume based on the master oscillator that drives everything.? For such an inexpensive device this level of accuracy simply amazes me.

TinySA Frequency Output Measurements	?	?
S/N SA-2009074	?	?
?	?	?
Frequency (MHz)	Error (Hz)	Error (ppm)
50	-17.5	-0.35
150	-53	-0.35
200	-70.8	-0.35
400	-139.8	-0.35
600	-208.9	-0.35
800	-278	-0.35

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not on mine

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I use a piece of 1/4 inch wood dowel that I sanded down to a dull point. ?I also went the extra step of using some wood stain to make it pretty, but that is a personal choice.