Topics

Anyone (US Only for now) need a uBITX Raduino repaired? #ubitx

Jim Sheldon
 

This is only for uBITX owners in the US right now as I don't want to get into the hassle of International shipping of repaired equipment as I am not sure how foreign customs handles repaired stuff duty and VAT wise and I don't have time to research it.  Also, international shipping rates from the US to other countries are extremely high so it isn't really practical.

Background - I just finished designing and building a Raduino test fixture that allows me to look at all the signals coming out of the board and also hook up all the digital controls to the board.  I have the equipment here to replace the Si5351 clock chip if it is bad and I can also replace a bad Nano (you provide the Nano).

Not sure how long I'll be able to offer this but I know there are a few of you out there that have somehow blown up your Raduino's and you can't easily get a new card yet.

For now, DO NOT send me your Raduino in need of repair without first contacting me outside of this group and discussing the problem with me.  I may refuse to work on it if it appears too badly damaged - that's at my discretion. 

The reason I built the test set was I blew up my own Raduino and with no new boards available it was either fix it or trash a completely good radio. 

The offered service is ONLY Raduino repair, not complete uBITX repair - that I don't have the desire to even think about.

Contact me via my QRZ address (email is listed there as well) if you are in need of Raduino repair service.

Jim Sheldon, W0EB
Park City, KS, USA

John Kemker
 

Hopefully, I won't need your service, Jim, but it's great to hear that you're willing to provide it!
--

73 de W5NNH

Christopher Miller
 

Sweet, now i just need a ubitx

Jim Sheldon
 

That DOES present a problem - LOL.

I found that one does NOT want to power the Nano using the Vin pin if you are using an external supply greater than 12VDC!  The on board LM1117 regulator can't take that with the load of the processor and the I/O on it.  Smoke, fire and flames in the regulator - overvoltaged the processor on the Nano, put more than 5 volts onto the I2C bus so it wiped out the Si5251 Clock chip as well.

I got a real education in replacing the 5351 - LOL.  I have a cheap hot air rework station and it did a nice job removing the dead chip.  I have been playing with the idea of possibly breadboarding a Raduino and have some carrier PC boards for the 5351's.  Still have to solder the chips on the boards though.  I bough a handful of 5351A's from Digi-Key for 91 cents US apiece. 

The way to go was Chip Quik's "Tack" flux - not cheap but 10ml for $20 bucks will last a LOOOONG time.  Dab of it on each pad, position the chip carefully over it's pads and using a needle point tip on my soldering iron, tacked each pin to the board.  I made up a probe for my DVM using a small sewing needle and was able to confirm continuity and no shorts on all the pins.  Programmed a new Nano and replaced the one that burned up (put machined pins and sockets on things this time).  Everything fired up and ran just fine.  Just after I built the test fixture, I read the frequencies of the clocks on my nicely calibrated uBITX and wrote them down.  With the test set, I can go into Factory Alignment mode and with a freq counter attached to the Clock 2 output, I can actually set the frequency accurately and save it.  The BFO can be read on clock 1 and I had those figures too so setting it to the right frequency was a breeze.  After the repair, I re-installed it in the uBITX, tuned to WWV at 5.000.00 MHz (the only one I can hear in Kansas during the daytime) and I was only off by 150 Hz.  Sure saved a lot of time being able to pre-calibrate the clocks outside of the radio!

The only drawback is - the clocks have to be calibrated to the specific radio for accuracy, due to the variations in crystal filters.  You can, however get very close so if I had to replace a Nano for someone, I could pre-calibrate the clocks to close proximity of what they should be and the user could fine tune them in his/her rig.

Jim - W0EB

KC9SGV <kc9sgv@...>
 

Hi Jim,
Good to know.
I might need your service later....
Ordered all the parts to try myself first.

The Raduino seems to be the Achiles heel here.
Break it, by reversing the connectors, or short some part of it out to ground by way of shoddy assembly practice, and your radio is done.
A Raduino replacement service is needed.
Not sure that HFsigs can keep up with that as well.

Bernie
KC9SGV


On Feb 5, 2018, at 4:20 PM, Jim Sheldon <w0eb@...> wrote:

That DOES present a problem - LOL.

I found that one does NOT want to power the Nano using the Vin pin if you are using an external supply greater than 12VDC!  The on board LM1117 regulator can't take that with the load of the processor and the I/O on it.  Smoke, fire and flames in the regulator - overvoltaged the processor on the Nano, put more than 5 volts onto the I2C bus so it wiped out the Si5251 Clock chip as well.

I got a real education in replacing the 5351 - LOL.  I have a cheap hot air rework station and it did a nice job removing the dead chip.  I have been playing with the idea of possibly breadboarding a Raduino and have some carrier PC boards for the 5351's.  Still have to solder the chips on the boards though.  I bough a handful of 5351A's from Digi-Key for 91 cents US apiece. 

The way to go was Chip Quik's "Tack" flux - not cheap but 10ml for $20 bucks will last a LOOOONG time.  Dab of it on each pad, position the chip carefully over it's pads and using a needle point tip on my soldering iron, tacked each pin to the board.  I made up a probe for my DVM using a small sewing needle and was able to confirm continuity and no shorts on all the pins.  Programmed a new Nano and replaced the one that burned up (put machined pins and sockets on things this time).  Everything fired up and ran just fine.  Just after I built the test fixture, I read the frequencies of the clocks on my nicely calibrated uBITX and wrote them down.  With the test set, I can go into Factory Alignment mode and with a freq counter attached to the Clock 2 output, I can actually set the frequency accurately and save it.  The BFO can be read on clock 1 and I had those figures too so setting it to the right frequency was a breeze.  After the repair, I re-installed it in the uBITX, tuned to WWV at 5.000.00 MHz (the only one I can hear in Kansas during the daytime) and I was only off by 150 Hz.  Sure saved a lot of time being able to pre-calibrate the clocks outside of the radio!

The only drawback is - the clocks have to be calibrated to the specific radio for accuracy, due to the variations in crystal filters.  You can, however get very close so if I had to replace a Nano for someone, I could pre-calibrate the clocks to close proximity of what they should be and the user could fine tune them in his/her rig.

Jim - W0EB

Jim Sheldon
 

Hope you do fix it yourself Bernie, It can be a real learning experience and if not, I'll be glad to try and help.  The only really tricky part is replacing the 5351.  Everything else is pretty straightforward.

If you have an oscilloscope,and frequency counter, carefully probe the clock outputs on the bottom pins of the Raduino. Clock 0 is the BFO and should show a sine wave with a frequency of 11995-12000 KHz  Clock 1 will show the receive local oscillator and clock 2 will show the transmit oscillator.  If in CW mode it should show the exact frequency the display is tuned to.

Jim Sheldon
 

OOPS, Regarding Clock 2, it will show the display frequency only in CW mode and only with the key down.

Jim - W0EB