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Re: 28khz
On Sat, Nov 16, 2024 at 09:23 AM, valis wrote:
Is the tiny sa ultra capable of glitching and self generating a 28khz signal? Even without an antenna? Please see attached. I get the same signal at a level of -48 dB on my Ultra with a short on the antenna input.? It is a spur generated inside the tinySA.
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BUT - You are operating below the published performance specs for the product.?
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Re: Choosing an attenuator
¿ªÔÆÌåÓýHi MDW, Come off line with your address and I'll send you 2ea 30db 1W
attn, no charge. (CONUS only, these items were part of a pkg I
cannot sell overseas, sorry) Mike C. Sand Mtn GA On 11/14/2024 12:53 PM, Flex-tech via
groups.io wrote:
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Re: Possible design issue with TinySA Ultra.
This bit my former employer in a wireless intercom beltpack we made. TRRS jacks didn't hold up as well as the XLrs. All it took was a dangling headset cable to snag on something as the user moved and the connector popped right off the board. We replaced a lot of mainboards under warranty. The solution was to use larger solder pads. I don't know how well it worked out.
On Fri, 15 Nov 2024 04:52:41 -0800 "Dallas N4DDM via groups.io" <mylastname@...> wrote: I see this kind of stuff all the time, and I think it comes from Engineers and CAD layout folks who never repaired things before they went to engineering school. -- 73 -Jim NU0C |
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Locked
Re: Possible design issue with TinySA Ultra.
I see this kind of stuff all the time, and I think it comes from Engineers and CAD layout folks who never repaired things before they went to engineering school.??
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There are times when SMT connectors should NEVER be used. My rule is that if the pressure to insert/remove the connectors is more than the pressure you would let somebody else use to insert/remove contacts in your eyes then you need a through-hole connector.??
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There is clearly enough room around that connector for through-hole pins and at a minimum the pads could have been 2-3X bigger...??
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Too many CAD layout folks get caught up in using SMT connectors because in the early days of PCBs drill sizes (diameter of the holes) and the number of holes jacked up the cost of the PCB...??
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I've seen too many PCBs destroyed because the SMT pads and many of the traces got ripped off the board because just a little too much force was used...
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73 Dallas N4DDM
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Possible design issue with TinySA Ultra.
Hi, First let me say I'm glad this device exists so I don't have to lug my 35kg 40 year old SA around... However, having said that I have to point out a serious design flaw (and rant somewhat that it is not an open source design which would make repair so much easier). So I was pretty happy to be able to purchase my TinySA from a local reseller here in Poland after he confirmed he got it from Zeenko's. I was happily using the SA for testing the output of my ham radio amplifier when I thought. What is this "Listen" option in the menu? Can it possibly demodulate audio signals? So I took my headphones and I inserted them normally into the jack, but it felt very loose and the plug fell out when I lifted it. There was no crack felt when inserting. Minimal force was used (I've owned mini jack equipment for ages, including ones with the port on a bare pcb, I know what force to use to plug it in). So I inspected the port closer and I noticed the receptacle is not there. I opened the device and I saw the carnage and the design flaw that led to it.? The receptacle is an smd part and all the support it has is in a form of very narrow cutout around the mouth. There was not even the "hot snot" type of glue around it as support. There is no back support. The part simply torn out of the pcb and damaged what I assume is a voltage regulator for the sd card behind it. This picture was taken after I very carefully placed the voltage regulator back on its pads.? Is it possible I got a previously broken and returned unit from the seller? I initially thought so, but I reviewed my "parcel opening" video and there was no gaping hole where the audio port is and I doubt the receptacle would just sit there held by the case cutout. So it appears when I tried to plug it in it indeed ripped out of the pads. To add insult to injury, the design is not open source (despite being based on nanovna that is, which made me assume it too would be open hardware) ... So I have no idea what the value of now missing r32 resistor should be. When I blew up an RF switch in nanovna I simply looked up the schematic online, ordered a part from China and replaced it myself. Here it is not possible. But what about clones? Don't I understand, open hardware designs get cloned? So does current TinySA Ultra. Not being open hardware has not stopped cloners one bit, but it hinders end users in attempts to repair the device. The only reason why I could figure out the chip is a voltage regulator is because I saw such regulators before. I did manage to fix it with wires. I also lubricated the mini jack receptacle and tried to insert/retract the plug few times after the repair. It holds for now. I'll probably be applying the hot snot to stabilise it further if someone could measure that resistor and let me know it's value so I can replace it first. Maybe it is 10k?. So here you have my feedback. Why do I think it is a design flaw? Well, for one, if a smd part is used and through hole is absolutely impossible for an audio jack the case should be formed in a way that provides support behind. At the very least some sort of glue (preferably hot melt so it can be removed for repair) could also be used for purpose.? I realise the "listen" feature is not that important. It's more of a gimmick as it only supports AM (my signal is SSB so I couldn't listen anyway), but in the process of messing up the jack port a very important feature (the ad card port) was damaged. I'm pleased to report the SD card works fine. I haven't tested listening yet (without the final grounding resistor), but it should work too.? Regards,? F |
Roger Need
Mike C.
Jim Shorney
Dallas N4DDM