Hi,
Last Friday a thunderstorm passed directly overhead and produced three lightning strikes. My U3s was transmitting on 40m wspr at the time into a random wire against a ground network of 8 copper clad steel rods.
At 7pm UK time the u3s was being spotted as normal, the storm passed overhead just after 7. No more spots were made, it should have sent at 7:10pm. 
I checked on the u3s a little later, lcd working, went through a tx cycle and calibrated ok but no spots so I decided to check the output. The u3s lives outside in a brick outhouse powered by a 12v 7ah battery. On picking the u3s up it was noticed that the power leads from the battery had fused together, the +ve lead had melted through to the copper wire in a couple of places but not shorted. I don't have a fuse installed but I do have a 3a diode for polarity protection. 
Put the u3s onto a power meter and output was nil, opened up the case and was met by a pungent smell. Further inspection showed that all three bs170's were damaged, the original supplied one was worst hit. The bias resistor had fused it's body to the first pa transistor, a nearby cap and resistor were scorched and the board badly damaged underneath the first transistor, burnt underneath the other two. 
The first transistor had cracked open and was white, it looks like most of the pa section had been affected. 
Power before it stopped was less than 400mW. Anyway, board is scrap, traces have gone, replacement ordered. 

Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.

I think that's just a simple board with traces on each side, like Alan recommended I would try a repair. Clean up the traces with a Fiberglass scratch pen brush and replace the traces with wire. If a through-hole is smoked it might take some ingenuity for repair. Repair would be faster than building a new U3S.

Sometimes I'll shut down my U3S with an approaching storm and sometimes not. My 132' long end fed dipole lives in the trees so maybe that helps it hide from lightning LOL.
--
John, WB5THT

 

Hi All

 

Can I ‘share’ One QRPLabs GPS with two side by side u3S’s

Any issues I need to think about?

Thanks guys.

73

Paul M0BMN

 

Sent from Mail for Windows 10

 

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Hi,
Last Friday a thunderstorm passed directly overhead and produced three lightning strikes. My U3s was transmitting on 40m wspr at the time into a random wire against a ground network of 8 copper clad steel rods.
At 7pm UK time the u3s was being spotted as normal, the storm passed overhead just after 7. No more spots were made, it should have sent at 7:10pm. 
I checked on the u3s a little later, lcd working, went through a tx cycle and calibrated ok but no spots so I decided to check the output. The u3s lives outside in a brick outhouse powered by a 12v 7ah battery. On picking the u3s up it was noticed that the power leads from the battery had fused together, the +ve lead had melted through to the copper wire in a couple of places but not shorted. I don't have a fuse installed but I do have a 3a diode for polarity protection. 
Put the u3s onto a power meter and output was nil, opened up the case and was met by a pungent smell. Further inspection showed that all three bs170's were damaged, the original supplied one was worst hit. The bias resistor had fused it's body to the first pa transistor, a nearby cap and resistor were scorched and the board badly damaged underneath the first transistor, burnt underneath the other two. 
The first transistor had cracked open and was white, it looks like most of the pa section had been affected. 
Power before it stopped was less than 400mW. Anyway, board is scrap, traces have gone, replacement ordered. 

Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.