Just repaired a Sansung Plasma monitor. ?The Sansung designers went to great lengths to provide proper shielding for the HV supply and used ?RF chokes on the control leads.
One of the main problems with Plasma TV's, tends to be the Plasma itself, which is basically an electric arc contained in a gas, and if the screen is of a decent size, it can radiate significantly.
LED TV's are a lot better in this respect, and personally, if presented with a Plasma TV to fix, I'd probably suggest that it was more 'economical' to replace it with a new LED TV instead.
Just repaired a Sansung Plasma monitor. ?The Sansung designers went to great lengths to provide proper shielding for the HV supply and used ?RF chokes on the control leads. ?If someone, ?who has repaired the monitor, ?did not put *all* the shields back on properly, that device will certainly be a great source of RFI. ?
Many repair tech has no clue regarding RFI suppression ¡ -- 73, Bernie, VE3FWF (most typos in this message were generated by highly sophisticated auto-correction software)
OK - here is my take on the "minimal" tinySA case - sized to only accept the tinySA with no accessories (but I think the guitar pick should fit in the space between the sma connectors).? As before, I am just uploading the files here for those who may want to print it, prior to creating another "thing" on thingiverse.? If anyone does print it, PLEASE provide feedback and confirm fit.??
As before, there are two versions which share a common lower case.? The upper case changes depending on whether you have the correct foam pieces to use in the upper case (roughly 3.25mm/1/8" thick neoprene). If you DON'T have the foam, print the 'nofoam' upper case. If you DO have the foam, print the 'foam' upper case.
All previous comments in this thread (and the original Thingiverse page for post printing still apply), and the hardware is still the same (M3 x 40mm SHCS x 2, M3 nylon locknut x 2, M3 washer x 4).
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/
Ham Radio
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Chris Shaker, KJ7BLE