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Hi All! Some years ago I bought and built an Ultimate 3S kit and it worked straight away, but I didn't use it on the air. It has a QLG1 GPS receiver and the additional filter board with five filters installed.
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Yesterday I finally decided to put it on the air. I found that I'd set it up for Hell on the 10m band. It set its clock automatically from the GPS signal All good.
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Then I hit the wrong button on my power supply, accidentally switching the output from 5v to 20v. The output was automatically disconnected, but I hadn't noticed the accidental range change and reconnected the output. Needless to say, I've damaged my U3S. The QLG1 is still working (the flashes are correct, I haven't checked the serial output), the LCD may be working, it has one row of character positions active but no characters showing. The backlight is off but that was set for brightness control by the Atmega chip. If I'm lucky, a replacement chip? (and program) might be all I need. Of course the Si5351 might be damaged too. There is no sign of activity on that board or on the Atmega, but the Si5351 might have been protected by the LM317 on its board.
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I haven't been able to find the UK pounds prices on the QRP Labs shop site. I'm willing to buy a new kit for the U3S but I'd quite like a quicker solution if it's just a case of replacing the microcontroller.
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73 and Happy Christmas,
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John G4EDX
Nottingham, England
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Hello John
This is what you need You can click the currency icon in the top left of the QRP Labs shop screen to price and shop in UK pounds.?
I have done the exact same thing myself... the most horrible example was back in 2017 one freezing (to me, at least, having left UK for a few years) morning in Newark, at the UK National Hamfest where I was an exhibitor that year. I was setting up my working display equipment and I had a "12V" unregulated power supply with me which of course really read 19V, and I accidentally connected it to a set consisting of U3S, VFO and Clocks which were expecting 5V. Of course all three died instantly. Luckily I had some spares for some of the chips, and I had my laptop and some blank chips and an AVR programmer, so I was able to quickly replace all three chips and everything came back to life, without any other damage.?
So there's no guarantee - but if you are lucky, the LCD and the '5351 module survive, and all you need is a new microcontroller.?
Hi All! Some years ago I bought and built an Ultimate 3S kit and it worked straight away, but I didn't use it on the air. It has a QLG1 GPS receiver and the additional filter board with five filters installed.
?
Yesterday I finally decided to put it on the air. I found that I'd set it up for Hell on the 10m band. It set its clock automatically from the GPS signal All good.
?
Then I hit the wrong button on my power supply, accidentally switching the output from 5v to 20v. The output was automatically disconnected, but I hadn't noticed the accidental range change and reconnected the output. Needless to say, I've damaged my U3S. The QLG1 is still working (the flashes are correct, I haven't checked the serial output), the LCD may be working, it has one row of character positions active but no characters showing. The backlight is off but that was set for brightness control by the Atmega chip. If I'm lucky, a replacement chip? (and program) might be all I need. Of course the Si5351 might be damaged too. There is no sign of activity on that board or on the Atmega, but the Si5351 might have been protected by the LM317 on its board.
?
I haven't been able to find the UK pounds prices on the QRP Labs shop site. I'm willing to buy a new kit for the U3S but I'd quite like a quicker solution if it's just a case of replacing the microcontroller.
?
73 and Happy Christmas,
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John G4EDX
Nottingham, England
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Hi John,?
I have a spare chip I could send you if you want one.
Andy
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The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.
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Hi Andy, that's very kind. My address is correct in the callbook and on QRZ.com. How may I pay you, and how much?
I'm hoping it's just the Atmega chip that's suffered and not the Si5351 which I see has its own LM317 on the board.
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73,
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John G4EDX
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Hi John,?
Don't worry about money, others have done favours for me so it's a pleasure to do one for you.
I'll check your address later and get it into the Christmas Post madness.
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.
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Aah, I don't have call book and your full address is not on qrz, my email is aeustace@.... send it there please.?
Andy
--
The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.
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Easily done John, I’ve done it myself. Unfortunately I had to replace the Si5351 module as well as the MCU. Although it has an onboard regulator, I think it received something disagreeable up the I2C bus. Hopefully yours will fare better. Cheers Nick G0OQK
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Thanks Nick. It's a case of wait and see. So frustrating that I've had the U3S for a long time, just decided to use it in earnest and blew it up within a day. Somewhere I've got two 5v 200mA potted linear power supplies, mains in 5v DC out. I should have used one of those. They're good for 200mA and my boards draw about 150mA.
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73, John G4EDX
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I wish you well John. ?The unit I blew up belonged to my father in law, also a G4, who is a few months shy of his 100th birthday. ?I built my non S version a good few years ago, with a 5v regulator for the MCU and an 8V regulator for the PA. ?I had completely forgotten this and was used to running mine off 13.8V. ?His had been built for an external 5V supply, when I fed it with 13.8V, it immediately died. Whoops. All fixed now though. 73 Nick G0OQK.?
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Happy ending! Thanks to Andy M0RON and all those who offered support and encouragement, my U3S is back on the air. The Si5351 survived the ordeal and I'm listening to my CW ID on the station receiver. I'm still feeding a dummy load until I get familiar with all the settings. Now where did I put that 5v supply?
73 all,
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John G4EDX
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All seems to be well with my Ultimate 3S now. I misunderstood about the dBm power setting in the menu, thinking I could control the power for there (although I couldn't see how). Now if I understand correctly, it's a way of inserting the (measured) power into the WSPR signal.
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To help me visualize what's happening with the relays and filters I've soldered surface mount green LEDs and 1k resistors across the relay coils so now I have confirmation of which filter is in circuit. I've labelled the filter sockets with numbers 0 to 5 at one end and the band values at the other so I can put the filters back in the right places if ever they come out.
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Thanks again to all who helped me with this.
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73 and Happy Christmas,
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John G4EDX
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Good result John, glad the damage was limited to the MCU. ?You are correct that the power setting is only an indication inserted into the WSPR message. The only way to vary the power in the U3S is by adding extra BS170 transistors and increasing the voltage on the PA. ?It’s detailed in the manual. ?I run my PA on an 8V supply. 73 Nick G0OQK
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Thanks Nick. How many PA transistors do you have? I thought I'd fitted three in mine but I see there's only one. I bought extra BS170s at the time.
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I'm now looking at housing the transmitter. I fitted a right-angle SMA socket last night so now it won't fit the original box. If I'm changing to a bigger box it opens up more possibilities; antenna switching relay, relay-switched attenuator, bigger front panel and so on. I'll feed the box from the station power supply or its own 12v supply and have linear regulators in the box for 5v and perhaps 8v or 9v for the PA.
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Turning the assembly over (yet again) last night I ripped the ground pad off the board. The corner mounting holes are plated through and at ground, so I'll use one of those in future.
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73,
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John G4EDX
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Hi John,
Glad you're nearly sorted. I don't use sma fittings on the relay board, I just solder coax direct, there are 3 large pads next to the sma placement. It also allows plenty of clearance should a gps board be fitted to the stack.
Andy
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The universe is made up of Protons, Neutrons, Electrons but contains only one M0RON.
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I fitted all three to mine John. My U3 isn’t currently on the air due to a rearrangement of my antennas, though previously it has provided years of continuous service, it is just coming up to 11 years old. I remember that the GPS chip required some careful soldering, as this was before Hans developed a dedicated GPS module. 73 Nick G0OQK
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M0RON