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ubitx raduino issue/AKA the radio doesn't receive

John Knoper
 

My receiver hasn't worked since I got the kit.   I've put a frequency counter (Fluke 115 multimeter) on the raduino/ubitx connector, and clk0, clk1, and clk2 all have no signal. Display is lit and counts. The raduino is in the right position on the header (per mapping the ground pins on both boards), and the radio does not receive. Regulator 12VDC in, 5VDC out. Can anyone make a suggestion to get this radio up and running?  I'm pretty savvy when it comes to computers and electronics, but...  arduino is not currently in my skill set.
Thanks!

Jerry Gaffke
 

That Fluke 115 is good to a max of 50khz as a frequency counter:
    http://en-us.fluke.com/products/digital-multimeters/fluke-115-digital-multimeter.html#techspecs

You want something that can count at 1000 times that fast if you want to see clk#1 and clk#2.
If you have or can borrow a shortwave receiver, bring the whip antenna within a few inches of clk#0 (without touching),
see if you can hear the BFO at around 11996.500 khz.  Use the "SSB" mode of the receiver if it has one
and you will hear a tone, though AM mode will work and you will hear the receiver go quiet has it hits that carrier.

Lots of things that could be wrong, but that's the first thing to check.

On many of these, the BNC antenna connector is not quite machined right, try wiggling the antenna cable.
(That's really an issue when transmitting for those pushing the final to higher power and worried about SWR.)

Jerry


On Mon, May 14, 2018 at 05:49 pm, John Knoper wrote:
My receiver hasn't worked since I got the kit.   I've put a frequency counter (Fluke 115 multimeter) on the raduino/ubitx connector, and clk0, clk1, and clk2 all have no signal. Display is lit and counts. The raduino is in the right position on the header (per mapping the ground pins on both boards), and the radio does not receive. Regulator 12VDC in, 5VDC out. Can anyone make a suggestion to get this radio up and running?  I'm pretty savvy when it comes to computers and electronics, but...  arduino is not currently in my skill set.
Thanks!

John (vk2eta)
 

Hello John,

I suspect that there is no communication with the Si5351 or that the chip is dead for some reason.

Since you know your way around computers I am assuming that you have installed or can install the Arduino IDE and upload a program.

In the files section of this forum I have uploaded a diagnostic program (see link below) that will perform the following tests, in sequence, on the I2C bus between the Arduino and the Si5351 clock generator:

1. Is the bus locked by a device other than the Arduino (could be a short on the bus lines)?

2. Is the Si5351 accessible at its default address?

3. Can we write to a register of the Si5351.

That would give you some clues as to where to search for the problem next.

All the best,

73, John (VK2ETA)

Program is located at at https://groups.io/g/BITX20/files/uBitx%20Diagnostic%20software%20by%20VK2ETA.

Some pointers:

How to setup the Arduino IDE and upload a sketch:  http://ubitx.net/how-to-load-up-a-sketch-on-your-raduino/

The original software to be re-loaded after the tests (assuming this is the software you have in the Raduino): https://github.com/afarhan/ubitx

John (vk2eta)
 

Jerry and I were replying at the same time. Do his test first.

73, John (VK2ETA)

John Knoper
 

Awww maaaaaaaan-  Thanks Jerry- I'll see if my 735 will pick it up!  And it does!!  right smack dab at 11996.5

John Knoper
 

thanks for the info, John.  I'll take a look at what you've listed, but, as per usual, I left a couple of things out of my problem description that might help diagnose my issues.  I was able to load CEC 1.06 to the raduino, and it appears all functions work, so far as I've taken it.(no transmitting)  Does that add any applicable info?
Thanks

John (vk2eta)
 

Sorry John, but when you say all functions work, you mean the display functions AND receiving or just display functions?

73, John

John Knoper
 

raduino functions- those visible.  That is to say, tune up/down, menu select.  Receiver does not receive, static can be heard, some birdies can be heard, noise level goes down when antenna disconnected.

John (vk2eta)
 

Ok thanks, then I would say your click generator is working fine, and most likely your receiver chain.

I would double check the calibration and more likely the BFO frequency.

There may be better methods, but I would reload the factory default sw, disconnect the PA power cable,  press and hold the push button at startup, do a factory calibration using your other Trx, then go in the setup menu and do a calibration and BFO frequency alignment as they return to defaults under that software.

Hope that helps,

73, John

John Knoper
 

thank you, I'll try to track all that info down.  

M Garza <mgarza896@...>
 

John,
You will need to do the front end diode protection mod before you transmit near your bitx40 or you can blow the front end...  I will look for the info and will post it here.

Marco - KG5PRT 

On Mon, May 14, 2018, 10:01 PM John Knoper <knoperj@...> wrote:
thank you, I'll try to track all that info down.  

M Garza <mgarza896@...>
 

Here is a link to the info:

Hope this helps,

Marco - KG5PRT 

On Mon, May 14, 2018, 10:07 PM M Garza <mgarza896@...> wrote:
John,
You will need to do the front end diode protection mod before you transmit near your bitx40 or you can blow the front end...  I will look for the info and will post it here.

Marco - KG5PRT 

On Mon, May 14, 2018, 10:01 PM John Knoper <knoperj@...> wrote:
thank you, I'll try to track all that info down.  

Dennis Yancey
 

John,
once again, your software saved me tons of time in troubleshooting. It turns out I have a bad 5351 on the Raduino now.. looking for possibilities of replacing it either as a chip or completely as a unit.

Thanks again..
--
72 and God bless
KD4EPG

zl1rd@...
 

Hi John

Wonder if you have solved this problem?  I just finished my uBITX and experience the same issues you have....  receiver sensitivity very low etc.  Would you mind responding to zl1rd@... and let me know about the progress you have made.  Your help is much appreciated.

Regards,


Rob
zl1rd

Evan Hand
 

zl1rd,

Most likely the problem is the BFO adjustment.  We would need more information on which model and what equipment you would have for testing.

I personally have found a free Audio Spectrum Analyzer (google one on the net) was the most helpful.  You can plug in a usb mic, have it close to the speaker of the uBitx, tune to a clear frequency, and adjust the BFO for the noise plateau to be centered between 500 and 3,000 hz.  The BFO has the most impact on the receive sensitivity.

There are other methods on groups.io.  You can search for them with BFO Setting or something simalar, just remember that the v3 and v4 are at a different frequency than the v5.

Hope that helps,
Evan
AC9TU
 

Gordon Gibby
 

you can use any waterfall (e.g. FLDGI, or even packet sound card software) to do the same.


On Tue, Nov 12, 2019 at 2:45 PM Evan Hand <elhandjr@...> wrote:
zl1rd,

Most likely the problem is the BFO adjustment.  We would need more information on which model and what equipment you would have for testing.

I personally have found a free Audio Spectrum Analyzer (google one on the net) was the most helpful.  You can plug in a usb mic, have it close to the speaker of the uBitx, tune to a clear frequency, and adjust the BFO for the noise plateau to be centered between 500 and 3,000 hz.  The BFO has the most impact on the receive sensitivity.

There are other methods on groups.io.  You can search for them with BFO Setting or something simalar, just remember that the v3 and v4 are at a different frequency than the v5.

Hope that helps,
Evan
AC9TU