Date   
Re: New uBitX - Start up Questions...

Jerry Gaffke
 

The uBitx mixers use schottky diodes, they are level 7 mixers.
They don't quite see 7dBm from the LO though, they get several dB down from that.
So the receiver loses a few dB of dynamic range at the top end, not a major issue.

Jerry, KE7ER


On Thu, Aug 1, 2019 at 03:43 PM, Christopher Ryan wrote:
Does anyone know the LO Drive level being used with the double balanced mixers off-hand? I suppose I could look it up on the data sheet for the synthesizer, but not in a place to do that at the moment.
Christopher

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

If you are going to use a Raduino with its 25mhz reference oscillator,
you probably want to move the crystal filter to something other than 25mhz.

Jerry



On Thu, Aug 1, 2019 at 09:02 PM, Jerry Gaffke wrote:
Those wishing to build one could borrow the Raduino from a *Bitx* rig
and not bother building the Nano/Si531/Display part of the Antuino.

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Ashhar Farhan
 

24 mhz would be a good idea. If you have borrowed the raduino. Alternatively, as I did, you can order a qrp labs Si5351 board. It is nifty, you should have a couple in your drawer.


On Fri 2 Aug, 2019, 9:50 AM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
If you are going to use a Raduino with its 25mhz reference oscillator,
you probably want to move the crystal filter to something other than 25mhz.

Jerry



On Thu, Aug 1, 2019 at 09:02 PM, Jerry Gaffke wrote:
Those wishing to build one could borrow the Raduino from a *Bitx* rig
and not bother building the Nano/Si531/Display part of the Antuino.

Re: Cool cheap oscilloscope for troubleshooting

kh6sky
 

Hi Graham,

Which link are you referring to?
It's a minefield out there' for sure.

Jim KH6SKY

Re: Cool cheap oscilloscope for troubleshooting

Tom, wb6b
 

On Thu, Aug 1, 2019 at 02:39 AM, David Wilcox wrote:
 The reference manual reads like a college text book
Hi,

I've looked at the "Analog Discovery" Digilent scopes. I can understand why the manual would be a densely packed tome. The Analog Discovery is nearly a universal device and the whole universe of what is does as well as how to create those universes is likely covered in the manual. 

So for a beginner you have to take a big bite to get through it.

However, if you just pick out one thing, the simplest examples that hopefully exist in the manual of how to look at analog analog waveforms and go with that for now, likely you can have some success and fun learning how to use an Oscilloscope. Even though the scope first requires you to understand how to make the circuitry in the Digilent device to "assemble" itself into an oscilloscope by doing something from the control software to upload the "scope circuitry" to the Digilent device.

If you stick with the "Analog Discovery" module it looks like you can get a lot of mileage out of it as you learn more.  Hopefully, there are videos that users of the device have put up in an effort to help others use it. Once you get through that you should be able to relate the instructions/videos on more generic scopes to what to do on the Digilent scope.

Tom, wb6b

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Tom, wb6b
 

On Thu, Aug 1, 2019 at 09:02 PM, Jerry Gaffke wrote:
For example, watching I2C and UART traffic on the Nano pins,
I've found this little $10 logic analyzer to be very handy for looking an I2C, encoders and other digital things.
https://www.amazon.com/gp/product/B07F8C1PMQ/

I use it with this software. The software will capture fairly high speed data for seconds on end and even display many data protocols in their decoded form.
https://sigrok.org

Tom, wb6b

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

24mhz might be problematic for the Antuino filter.
Perhaps 27mhz would be a better choice?
Or most any oddball frequency in that ballpark?

A few users were having trouble with the uBitx back when its filter
was at 12mhz, due to interference with local oscillators on the Nano.
Though typically not, since the ceramic resonators on the Nano
are not very accurate.  The second harmonic of 12mhz is 24mhz.

Jerry, KE7ER


On Thu, Aug 1, 2019 at 10:23 PM, Ashhar Farhan wrote:
24 mhz would be a good idea. If you have borrowed the raduino. Alternatively, as I did, you can order a qrp labs Si5351 board. It is nifty, you should have a couple in your drawer.
Hide quoted text

 


On Fri 2 Aug, 2019, 9:50 AM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
If you are going to use a Raduino with its 25mhz reference oscillator,
you probably want to move the crystal filter to something other than 25mhz.

Jerry



On Thu, Aug 1, 2019 at 09:02 PM, Jerry Gaffke wrote:
Those wishing to build one could borrow the Raduino from a *Bitx* rig
and not bother building the Nano/Si531/Display part of the Antuino.

Re: uBITX v5 Finished #3d_printing #calibration #v5

Bob KB1TEK
 

Hi Doug,

Did you design the microphone case yourself?  It looks great!

Could you point me to the models or more info?  I'm not yet great at 3D design.

Thanks and 73,
Bob KB1TEK

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Ashhar Farhan
 

27 mhz is tricky because a number of these crystals turn out to be 9 mhz crystals sold for their 3rd overtone.
The 27 mhz filter was also horribly lossy. More than 13 db, if i remember correctly.

On Fri 2 Aug, 2019, 8:11 PM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
24mhz might be problematic for the Antuino filter.
Perhaps 27mhz would be a better choice?
Or most any oddball frequency in that ballpark?

A few users were having trouble with the uBitx back when its filter
was at 12mhz, due to interference with local oscillators on the Nano.
Though typically not, since the ceramic resonators on the Nano
are not very accurate.  The second harmonic of 12mhz is 24mhz.

Jerry, KE7ER


On Thu, Aug 1, 2019 at 10:23 PM, Ashhar Farhan wrote:
24 mhz would be a good idea. If you have borrowed the raduino. Alternatively, as I did, you can order a qrp labs Si5351 board. It is nifty, you should have a couple in your drawer.
Hide quoted text

 


On Fri 2 Aug, 2019, 9:50 AM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
If you are going to use a Raduino with its 25mhz reference oscillator,
you probably want to move the crystal filter to something other than 25mhz.

Jerry



On Thu, Aug 1, 2019 at 09:02 PM, Jerry Gaffke wrote:
Those wishing to build one could borrow the Raduino from a *Bitx* rig
and not bother building the Nano/Si531/Display part of the Antuino.

uBITX Calibration Question #calibration #ubitx

JT Croteau
 

Could someone please point me in the direction of how to calibrate the uBITX with a PC audio spectrum analyzer?

Many thanks.

Re: uBITX v5 Finished #3d_printing #calibration #v5

Doug Hall
 

Bob,

I didn't design the mic case - I got it from Thingiverse:
https://www.thingiverse.com/thing:3044144

It uses the mic element and microswitch that were included in the uBITX kit. I printed it with black filament and then rubbed some white paint into the front to give it some "character." I'm not sure I succeeded on that front, but the mic works fine.

I also printed the uBITX case from here:
https://www.thingiverse.com/thing:2823172
but I only used the front and rear panels. I designed my own middle section to add mounting holes and a baffle for an internal speaker. For that design I used FreeCAD.

73,
Doug K4DSP

Re: Antuino as a Spectrum Analyzer: Lots of birdies?

Jerry Gaffke
 

Hmm, if 27mhz crystals are often 3'rd overtone, I wonder if some of the 25mhz crystals are too.
Might want to be careful about exactly what brand of crystal is being used.

Arv had an interesting notion for a hobbyist's spectrum analyzer,
even simpler than the Antuino:  https://groups.io/g/BITX20/message/55902
The conversation there brings to mind a possible hack for the Antuino:

Add a second mixer, using the third output of the si5351, to convert the 25mhz IF to audio.
Have the si5351 a bit to one side of the 25mhz IF so we get single signal reception.
Monitor that audio using a soundcard audio spectrum analyzer.

This would allow us to easily differentiate by ear between first mixer images and primary signals,
the images move in frequency the opposite direction when the thing is tuned.
Also harmonics of the VFO, they would cause an audio tone that moves about 
faster than the VFO fundamental..
And the audio spectrum analyzer makes this a very fine grained tool, able
to distinguish between RF signals that are jsut a few hz apart.
Just listening to the resultant audio would be instructive.

Jerry, KE7ER


On Fri, Aug 2, 2019 at 08:12 AM, Ashhar Farhan wrote:
27 mhz is tricky because a number of these crystals turn out to be 9 mhz crystals sold for their 3rd overtone.
The 27 mhz filter was also horribly lossy. More than 13 db, if i remember correctly.

Re: uBITX Calibration Question #calibration #ubitx

Doug Hall
 

On Fri, Aug 2, 2019 at 11:03 AM, JT Croteau wrote:
Could someone please point me in the direction of how to calibrate the uBITX with a PC audio spectrum analyzer?

 JT,

Here's what I did, and it seems to work well. Note: I am using KB8CEC v1.2 firmware. I don't know if this applies to the stock firmware since I have never used it.

I downloaded Spectrum Lab from here:
https://www.qsl.net/dl4yhf/spectra1.html

Install it and run it and go to Options->Audio Settings and select your sound card for the device input. Click Apply, and then you should see the spectrum display. If you don't you might have to click Start->Start Sound Thread. And if you're using some spectrum analyzer software other than Spectrum Lab then things will be different, but that's the gist of it.

Now connect a 1/8" stereo cable from the uBITX headphone jack to the audio input jack on your PC. Then turn on the uBITX and select USB. I did this on 20M but I don't think it matters. Slowly advance the volume control until you see the audio passband rise up from the noise floor.  If you advance the audio too much you won't be able to distinguish the passband from the noise floor.

Now turn on Setup Mode in the radio firmware, and then select "Set the BFO." Now adjust the VFO knob until the upper corner of the passband is at 2300 to 2400 Hz. The lower corner will be around 300 to 400 Hz. Press the PTT button to save the values. Now select CW mode and then select "Set CW RX BFO" and repeat the process for CW.

I posted a screen capture of the Spectrum Lab program after I finished adjusting the BFO. Thanks to Adrian KK6VQK and others for this idea.

73,
Doug K4DSP

Re: uBITX Calibration Question #calibration #ubitx

JT Croteau
 

Doug,

Thank you very much for the detailed reply.  I will be working on it this weekend.

73
N1ESE 

On Fri, Aug 2, 2019, 13:56 Doug Hall <k4dsp.doug@...> wrote:
On Fri, Aug 2, 2019 at 11:03 AM, JT Croteau wrote:
Could someone please point me in the direction of how to calibrate the uBITX with a PC audio spectrum analyzer?

 JT,

Here's what I did, and it seems to work well. Note: I am using KB8CEC v1.2 firmware. I don't know if this applies to the stock firmware since I have never used it.

I downloaded Spectrum Lab from here:
https://www.qsl.net/dl4yhf/spectra1.html

Install it and run it and go to Options->Audio Settings and select your sound card for the device input. Click Apply, and then you should see the spectrum display. If you don't you might have to click Start->Start Sound Thread. And if you're using some spectrum analyzer software other than Spectrum Lab then things will be different, but that's the gist of it.

Now connect a 1/8" stereo cable from the uBITX headphone jack to the audio input jack on your PC. Then turn on the uBITX and select USB. I did this on 20M but I don't think it matters. Slowly advance the volume control until you see the audio passband rise up from the noise floor.  If you advance the audio too much you won't be able to distinguish the passband from the noise floor.

Now turn on Setup Mode in the radio firmware, and then select "Set the BFO." Now adjust the VFO knob until the upper corner of the passband is at 2300 to 2400 Hz. The lower corner will be around 300 to 400 Hz. Press the PTT button to save the values. Now select CW mode and then select "Set CW RX BFO" and repeat the process for CW.

I posted a screen capture of the Spectrum Lab program after I finished adjusting the BFO. Thanks to Adrian KK6VQK and others for this idea.

73,
Doug K4DSP

Re: Cool cheap oscilloscope for troubleshooting

Mark Hatch
 

In case no one else mentioned it, take a look at EspoTek Labrador. You can order it from Amazon for $29. Plugs into a breadboard (well sort of, a couple pins have to be persuaded ) and it includes a oscilloscope (0.75MSa/s), signal generator, volt/ohms, and a logic analyzer. Even has a power supply function. You run software on your windows/Mac/linux and control it thru a program. Again, not going to replace a full scope, even one that is 20-30 years old, but the board is 50mm/sq...  I throw it in my desk junk drawer and grab it if I want to look at something. Much easier on my back than going to the garage to fetch that Tek 475...

BTW: I am in the process of designing a 3d printed case with room for real BNC connectors. Will put it thingiverse when I am done.

73
Mark
AJ6CU

Re: Cool cheap oscilloscope for troubleshooting

Terence Taylor
 

Would be interested in the case when you upload it to ThingiVerse

keying errors ubitx

rickaputi@...
 

have a version 3 and version 4.   when using paddles for keyer function, spurious dashes are generated quite often when hitting the dit side, after the dit is generated.  no keying errors generated on the dash side.  interestingly, i found that changing the resistor from 2.2 k ohms to 2150 ohms prevented almost all keying errors.  discovered this using a resistor substitution box, then i combined resistors in parallel to match 2150 ohms.  not sure why the circuitry is so sensitive to such a narrrow range, but it did work.  still having lots of fun with ubitx!  many thanks to sthe guys who compiled the .tft for the 5 inch nextion.   woohoo !!   WA2TDL, Rick.

Re: Issues with ordering the BITX40

Jerry Gaffke
 

While you are at it, include a way to buy a Raduino.
That option seems to have disappeared from hfsignals.com


On Thu, Aug 1, 2019 at 07:21 PM, Ashhar Farhan wrote:
Yup,  'Group, we have a problem'. I will fix this Paypal trouble in 24 hours. Aah, the joys of Paypal customer service, here we go again...
- f

amatureradiokits enclosure question #ubitx-help #ubitx

Dean Souleles
 

Hi - I ordered a universal ubitx enclosure from amateureradiokits.in. Its a beautiful case and all the parts needed for a nice clean build are included. However the PCB they sent for the front panel display has a couple of problems. On the analog 8 connector port the hole for pin 6 is missing and the pin 2 and 3 solder pads are shorted. If I read the schematic correctly for the ubitx pin 2 is ground for the mic and pin 3 is ground for the volume so the short won't matter. And pin 6 appears to be unused. So if I clip pin 6 off the pin strip I think I should be able to proceed with the build, no harm, no foul. Yes? Thanks in advance from a newbie builder.

Dean

KK4DAS


Re: Issues with ordering the BITX40

Ashhar Farhan
 

I think that paypal has tweaked something and the old style button had stopped working. I will fix the raduino too.
- f

On Sat 3 Aug, 2019, 3:17 AM Jerry Gaffke via Groups.Io, <jgaffke=yahoo.com@groups.io> wrote:
While you are at it, include a way to buy a Raduino.
That option seems to have disappeared from hfsignals.com

On Thu, Aug 1, 2019 at 07:21 PM, Ashhar Farhan wrote:
Yup,  'Group, we have a problem'. I will fix this Paypal trouble in 24 hours. Aah, the joys of Paypal customer service, here we go again...
- f