OK - I will shrink it down to the minimum.? No place for the guitar pick "stylus" either?? I might have a natural place for that between the SMA connectors - we shall see...
Correct, no test leads, no antenna, no accessories, except the mounted SMA Savers. Once they are on with the correct momentum I don't want to remove them, but I want to protect the TinySA (NanoVNA) in a box. This could make the box as small as 7 x 11.5 cm or so, and printable on 14x14 printers. Thanks!
So just to be clear - are you looking for something that would just hold the tinySA and those attached connector savers?? No place for antenna or connector cables?
Also - to respond to Lawrance - if you are referring to the "narrow" case option, that was just a "hack" to see if I could squeeze a case onto a smaller print bed.? It sounds like the original commenter had something different in mind (hence my questions for confirmation on the size he is looking for).
A common SMA-saver is?SMA5071A1-3GT50G-50 from Amphenol Mounted on the case it will extend 18 mm from the plastic, 19 mm with the yellow plastic cap (as opposed to 6 mm and 7 mm respectively in normal cases) I have a NanoVNA 2.8" screen, in plastic case, which was the model used as template for the TinySA, so all measurements, buttons and connectors are identical. I double checked as I did the measurements.
If you can provide/confirm the lengths of the SMA savers (measured from the edge of the tinySA case, I could probably model something up (not as quick as the last one).? I don't have the nanoVNA, so I would have to take your word that it would fit.
I would prefer a smaller version that just has room for the TinySA with SMA-savers. A case like this would also work for my NanoVNA. Cables, attenuators, calibrations sets and more converters I keep in a different box anyway. Thanks!
My version shows up as tinySA_v1.3-111-gcb2fe54.? This is better that what is shown in the update video, so I'm wondering if I should even think about doing an update since the device seems to be working quite OK. syd/wt1v
Jim, I feel the pain of noise as well. I have noise sources that are well into my IC-9700 at 1296 here, and I'm out in the countryside by a good distance. One would think the area would be RF quiet but, with the occasional use of welders on nearby farms, electric fences, older power lines and transformers, a neighbors solar panels, another neighbors wind generator, not to mention the cell tower with apparently a large amount of LTE data on it in the field down the road and the surprise FM Broadcast tower a few short miles up the road it's noisier than I had hoped when we moved out here.
The FM station I only just discovered so close because it is the first thing I found when I turned on my Tiny SA for the very first time just 2 nights ago.? I too am in the process of sweeping the house and area for noise and find this little device amazing.
You are going to find a lot of weird stuff.? I once found a band blanking noise source in my kitchen late at night that was a total eye opener. A major appliance that had a single LED that led me to find it - our dishwasher. The heating element had an indicator LED as to when it was active. That heating element took me out totally on more than one band and took me about 6 months to figure out walking around with a small radio. This thing would have been so much faster. Intermittent use of the dishwasher made that even harder mind you.
Also, in my current house I have an LCD TV that makes far more noise when off (yes, when OFF) than when on.? I suspect a mostly unloaded PS is doing that. Anyway, best of luck in your hunting. Watch your steps when sweeping. Too wide a step and you may miss a narrow source totally.
On Fri, Jul 30, 2021 at 06:03 PM, Jim Dawdy wrote:
I would like to be able to do a more accurate and sensitive survey for stronger RFI sources in my home and neighborhood.? What settings would be good to plug into the SA so that I can get a bit more granular reading of RFI sources, identifying the worst offenders?
Hi Jim,
A lot depends on the type of noise source and it's location.
For 'sniffing' emissions from stuff in the home, such as power supplies, chargers and other assorted domestic electronics, where you can get right next to the item. A small antenna such as a short whip (E-Field probe) or 1" screened loop (H-Field probe) is usually good enough to identify the worst offenders. The noise level will increase dramatically, when you place the antenna alongside the offending item, so it's relatively easy to check though a room in just a few minutes.
In this instance I tend to use a relatively large bandwidth of 100KHz or larger, and a sweep width of 0-50MHz, in order to keep the sweep speed reasonably high, whilst being able to observe the most problematic part of the spectrum in one go, but this does mean that the overall sensitivity is reduced. When doing this, beware that any conductive material will act as an antenna, so it's quite normal to find that the noise source may increase in strength (along with SW broadcast signals) due to re-radiation from the conductor, when you bring your 'sniffer' antenna close to them.
When walking around the neighbourhood, trying to locate distant noise sources, I use a different tactic. In these cases it's usually better to concentrate on a specific frequency where you know the noise to be present, and use a narrower RBW and sweep width, so that you don't get confused by other interference and signal sources, that may not be what you are trying to find.
You will also need to use an antenna with some gain and directivity, as the TinySA isn't quite sensitive enough to be able to pick out weaker signals that you can hear on you main radio. Setting one trace to maximum hold is also handy, so that you can compare if you have passed the source and then determine if you are getting closer or further way from it.
I've successfully used a small tuned loop with a 50cm (20") diameter in conjunction with the TinySA to triangulate and locate noise from roof mounted solar panel optimisers, whilst walking around at street level.
There is a plan for a simple QRP tuned loop towards the bottom of this web page.
One other useful tool when interference hunting, is to implement the audio output modification on your TinySA. It's a lot easier to be able to listen and identify the interference whilst walking around rather than having to keep your eye on the screen all of the time, especially in bright sunlight.?
This video is for people that are more familiar with the tinySA and how it can be connected to a computer and how the tinySA can be controlled via the computer.
For new users? its best to follow the "tinySA first use" video:? That will show a far easier way to do power calibration of the low input.
Here is the full list of video's
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For more info on the tinySA go to https://tinysa.org/wiki/
This is from the example "Calibrating the low output level". The first part talks about setting up a 30MHz, -25 dBm signal and seeing it with a scope at the HIGH INPUT after setting CAL OUTPUT to 30 MHz. I thought the? high output/input was for above 350 MHz signals!? So why are we looking for a 30 MHz signal at the high port? Then we do a similar setting for the low output port and compare the levels for calibration.? In the example the signal level has to be corrected by -1.5dBm. So now we are supposed to? connect a USB cable and enter
leveloffset low output -1.5 saveconfig 1234
to calibrate the low output cal signal
Somehow the user has to? have a program running to enter these commands, and all I can see to do this is have a USB serial monitoring program installed.? A little more info here would be a great help. syd/wt1v
To answer the question from Christopher about the foam, I think this would be roughly equivalent to the foam I used for the upper case:
The above should be a 5-pack of 12" x 8" x 1/8" thick neoprene rubber closed cell foam - MAKE SURE it is the 1/8" thick option.? This is WAY more than would be needed, but it could have uses elsewhere, I suppose.? Reviews seem to indicate that some of the thicker options (1/2", for example) are a bit less than the nominal values stated on the product page.
The sheet material I used under the tinySA (lower case) is probably equivalent to this:
The above is a pack of 10 pieces of roughly 8" x 10" 1mm sheets.? From the reviews, it looks like this is not "grippy", but it doesn't really need to be.? I put the bottom rubber-like sheet in mine for cushioning more than for grip.? Really just about any 1mm thick material could work for the lower case application.
The power went out in my neighborhood yesterday after an early morning storm.? I got up and out of curiosity, hooked up my FTDX-1200 to the battery I keep handy for just such occasions.? I wondered what the noise levels would be like, and lo and behold, noise levels on every band were between S0 and S1, except for 80m,, which as expected was an S5.
With the power back on, the only band that's close to S1 is 30m.? All other bands are S4-5 with 15m being almost S8.? If I wander around with my tinySA and the telescoping antenna, the baseline noise level, without any adjustments to the default settings other than scanning the HF band, is about -95 to -80db across the bands.? If I put the antenna close (within a few inches) to something like a computer or fan, it drops down to maybe -70db, which i would pretty much expect..
I would like to be able to do a more accurate and sensitive survey for stronger RFI sources in my home and neighborhood.? What settings would be good to plug into the SA so that I can get a bit more granular reading of RFI sources, identifying the worst offenders?? In other words, to maybe discern an RFI source that's REALLY contributing to the S5 levels, as opposed to an RFI source that contributes only minimally.? I.e. to identify the worst offenders,? but those which are still not massively obvious +10dB RFI sources (which, thankfully, I don't seem to have).
I had thought to construct a simple HF loop antenna for DF such as the one here:?? to use.
Any thoughts are appreciated: I have hardly taken my tinySA out of the box, so I'm quite unfamiliar with it.
Carl-Mikael Zetterling
Chris Shaker, KJ7BLE