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Dear all,

I've been playing with my TinySA, and I think I've passed the measure power limit during some test and now my device doesn't measure correctly. Probably I exceeded the +6 dBm.

I've uploaded new FW and try to pass the self test, and I've obtained errors on tests: 3,4,7, 10,11 and 14. I attached a picture,

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Try to passed level calibration is not possible.

I've appreciated that if I inject a signal from a signal generator of value is attenuated but measurable, however if I turn on the LNA I can't see anything, so my first thoughts is going about the LNA is broken.
I've also tested the attenuator and it works well.

So I join this group with the hope that you could help me to solve the issue.

I also attach a picture of the back with the S/N.

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Thanks in advance for the support and I'll be waiting for your news.

Greetings,

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Jorge

Hello again,

Just for update about the thread, I've disassembled the TinySA and remove the U22, the RF Switch, and replace it by 0R jumper joinning traces.
The result is that the power values from CAL connector in 30MHz Output mode goes to normal values and "Safe Test" near pass succesfully. However when it needs LNA to measure it fails, which is normal, becouse know as I don't have RF switch it can measure anything in that trace.

I tried to calibrate it is not possible to finished it becouse also needs the LNA, but now the power values has more sense.

Probably I've to replace to the LNA, which I think is U14,and it will get back to the normally, but I need to know the PN to buy them.

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Could you tell me what are them?

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Thanks in advance.

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Greetings,

Jorge.

https://tinysa.org/wiki/pmwiki.php?n=TinySA4.FaultFinding

Hello Jorge,?

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LNA U14: BGA2817.?
e.g. Mouser part# 771-BGA2817115?

73, Thomas

(all parts from another posting:

- Input RF switch U22: XA17-G4K? ? or AS179-92LF ?(mouser 873-AS179-92LF)
- LNA U14: BGA2817 ? ? ? (mouser? ? 771-BGA2817115)
- Attenuator U38: PE4312C-Z ? ? ?(mouser 81-PE4312C-Z)? )

The LNA is only good up to 2.2GHz, thats according to Mouser. Since the LNA, when turned on bypasses the attenuator, do we have to expect large errors in gain beyond 2.2GHz? It looks to me that it can do a bit better but maybe not up to 5GHz.

Erik - do you compensate the display via the higher end (or manual) calibration for the decline of the LNA gain? Working with even higher harmonics (like the 7x -> 12GHz) the LNA seem useless, it just blocks everything, while surprisingly the other circuitry keeps up with the LNA turned off. Interesting...

The drop in gain above 2.2 GHz is very consistent and has fully been compensated in the factory calibration.

Above 6 GHz the ZS405/406 LNA is useless and better be disabled

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Designer of the tinySA
For more info go to

Hi Tom,

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Many thanks for your report! I've just ordered and now, I've to wait a little bit to get it in home.

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I'll keep you update when I'll replace them.

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Best regards from EA1FWI.

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73!

Dear all,

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Finally the parts arrived, and I started the IC changes.

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First, I removed the U22 0 ohm resistor, working as jumper, and place the RF Switch, and do recall. During recall it fault again, so I decided to change the LNA, U16.

After changed it and recall, the calibration from 100kHz to 5.327GHz goes succesfuly, and I passed to calibrate abovde 5.327GHz.

I've no idea that you need to generate signal from other device, so I used an ADALM-Pluto to generate the signal and power enough for calibration, and succesfuly it worked again.

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So now, my device is perfectly working and calibrated and I can play again with it.

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Many thanks to everyone for the help and we're in touch.?

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Sincerely,

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Jorge EA1FWI.