CQ DX >> MEET THE MICROBITX: A SIMPLE TO BUILD, ALL-BAND- Ham Radio TRANSCEIVER KIT

Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,542
edited 2019-04-05 - 01:16:07 in General Discussion
It's based on Arduino Nano controller and a Si5351 for all local oscillators

Its fun to modify and there is no reason why we can't pluck out the Arduino Nano and replace it with a Prop 1 or 2 :)

Arduino Code:
https://github.com/afarhan/ubitx4


I just ordered one and it may take a few months to get here :)

===================================================================================
t's a simple kit with most of the parts are pre-soldered( by women in India and soldering and winding inductor cores allows them to feed their kids :) ). It's 10 watts and inexpensive $US129, $CDN 176

MEET THE MICROBITX: A SIMPLE TO BUILD, YET CHALLENGING ALL-BAND TRANSCEIVER KIT

http://www.hfsignals.com/index.php/ubitx/

Receiver :

Sensitivity: a 0.2uv signal is clearly audible
Selectivity: 2.4 KHz, low ripple SSB filter with 8 crystals
RIT (Receiver Incremental Tuning)
Continuous coverage from 500 KHz to 30 MHz
Sideband selection
Detent-less encoder tuning. Tunes with larger step rates when tuned quickly
Transmitter

More than 10 watts up to 10 MHz, 7 watts up to 21 MHz, 2 watts on 28 MHz
CW transmit with the built-in keyer
Uses IRF510s x 2 as PA and 2N3904 x 4 drivers in push-pull mode for low distortion transmission.

uBITX HF Tranceiver - Overview


New All-band SSB/CW Micro BITX Now Available (AD #113)


N6QW builds the uBitx Multiband Bitx Transceiver






«1

Comments

  • MicroBITX: A simple to build, All band ham radio transceiver _NOT_ I purchased Version 3 and Version 4 when they first became available. Looking at the discussion groups, there were sooo many fixes and modifications needed to get the thing to work half way decently. Further circuit analysis showed that just about every sub-circuit had serious faults in it. It is so wonder that anyone got on the air with a decent signal, you spend more time fixing stuff than actually operating!
    Not to fear, I have been working on a brand new Parallax FLiP based ham transceiver for the last few months and making good progress. The software is pretty much written but still working on circuit details. Most of which are from various on-line and ARRL robust & proven designs.
    Since this is a brand new setup I have gone thru several design innovations. No knobs, no LDC display, no extra "stuff" All the features of the Propeller have been used, all the software from these forums has been used. A show piece to illustrate how the Propeller can be used in a practical and useful product. BTW - I still need help, especially with the 1st & 2nd IF designs. If you are interested in helping out, PM me for details. de W1HV
  • jmgjmg Posts: 13,615
    PropGuy2 wrote: »
    ...
    Not to fear, I have been working on a brand new Parallax FLiP based ham transceiver for the last few months and making good progress. The software is pretty much written but still working on circuit details. Most of which are from various on-line and ARRL robust & proven designs.
    Since this is a brand new setup I have gone thru several design innovations. No knobs, no LDC display, no extra "stuff" All the features of the Propeller have been used, all the software from these forums has been used. A show piece to illustrate how the Propeller can be used in a practical and useful product. BTW - I still need help, especially with the 1st & 2nd IF designs. If you are interested in helping out, PM me for details. de W1HV

    Interesting, is there a web page for what you have so far ?
    Will this port to P2 easily ?
  • Web page, no. I don't want to use any of the "Crowd Funding" type of introductions. Sooo... for now I am just working on getting the circuit to work and lining up parts suppliers (read DigiKey), and a local electronics assembly company to produce the basic RF circuit board(s). I have built lots of kits in the past, and kits have a way of never getting finished. This radio is targeted to the more than half of all Hams that are licensed, but NEVER get on the air. I will post pictures of this radio ( code named ACORN ) on this thread later. Also planning on setting up a booth at the Orlando HamCation, Feb. 8, 9, & 10th.
  • I love that you're using the FLiP module in your transceiver! It's an amazing product for a good price, and it would be hard to imagine a better entry ramp for designing a Propeller chip into one's product.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • jmgjmg Posts: 13,615
    PropGuy2 wrote: »
    ... I will post pictures of this radio ( code named ACORN ) on this thread later. Also planning on setting up a booth at the Orlando HamCation, Feb. 8, 9, & 10th.

    Maybe start a new thread, so the right title can apply, and you can also edit your first post to reflect updates ?

    What are you using for the clock/oscillators generate side ?
    PropGuy2 wrote:
    No knobs, no LDC display, no extra "stuff" All the features of the Propeller have been used, all the software from these forums has been used.
    With no knob(s), or LCD, what form does the user-interface take ?

  • Answers to questions: Porting to P2 is going to take awhile at least until the high level P2 SPIN is available. Using the P2 (i have one) still has a high learning curve & someday I may use it. I use most of the available commands and a lot of OBEX on the P1 to make the Ham transceiver work. The radio has not been on the air yet, so we will see. LOL
    I am using an RS-232 / capacitive touch keypad from FutureLec for all the front panel knobs & switches. The 16 keys can be user programed to do anything. Likewise I gave up on an LDC display. Using the VGA driver from Marko, with user programmable fonts and color palette.
    For clock and frequency generation I am using the available / built-in digital synthesizers on the Prop chip.
    Posts will be few, but intriguing!
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,542
    edited 2019-01-15 - 23:51:54
    @PropGuy2

    Your project sounds fascinating. I'm very interested.
    I am using an RS-232 / capacitive touch keypad from FutureLec for all the front panel knobs & switches

    Something like this:
    https://www.futurlec.com/Touch_Keypad.shtml

    TOUCH_KEYPAD_A600.jpg


  • jmgjmg Posts: 13,615
    edited 2019-01-16 - 01:30:50
    PropGuy2 wrote: »
    I am using an RS-232 / capacitive touch keypad from FutureLec for all the front panel knobs & switches. The 16 keys can be user programed to do anything.
    Likewise I gave up on an LDC display. Using the VGA driver from Marko, with user programmable fonts and color palette.
    That should port to P2 fairly easily, the P2 should manage a better VGA, via the inbuilt DACs

    PropGuy2 wrote: »
    For clock and frequency generation I am using the available / built-in digital synthesizers on the Prop chip.
    That part will not port so well to P2, as it has only one SysCLK PLL, it drops PLLs in the timers.
    Have you run those P1 parts up, to check the jitter and noise ? (The P1 PLLs are not really noise-optimized)

    The SiLabs i2c Si5351A looks to be quite popular for VFO use, and there are an expanding range of Silabs Oscillators, covering a price/performance range.

  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,542
    edited 2019-01-16 - 01:24:10
    @jmg
    The SiLabs i2c Si5351A looks to be quite popular for VFO use, and there are an expanding range of Silabs Oscillators, covering a price/performance range.

    That's what the MICROBITX is using: It's based on a Arduino Nano controller and a Si5351 for all local oscillators.

    Si5351 Spec Sheet:
    https://www.silabs.com/documents/public/data-sheets/Si5351-B.pdf
  • Bob VE1RRL - Yes that is the keypad. I use a paper overlay to redefine the keys, and the keys can be individually programmed to do what ever you want: VFO frequency, scan, read EEPROM, whatever you want. The uBITX uses a cheap mechanical encoder that will wear out in a few thousand cycles. Plus some of the uBITX functions are not very intuitive.
    I am using the built-in synthesizer function in the Prop chip. It may be too noisy. In that case I will go to the SiLabs Si5351A chip. BTW some of those frequencies may be noisy also, it is not perfect. Reports are that the uBITX has "lots" of spirs.
    Any other ideas on a digital frequency synthesizer (chip or otherwise) are welcome. Remember that I am using a 1st and 2nd IF frequency and mixing them using the SA612 ic chip(s) Challenging for sure.
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,542
    edited 2019-01-16 - 03:41:36
    @PropGuy2

    Great thanks!!
    Any other ideas on a digital frequency synthesizer (chip or otherwise) are welcome. Remember that I am using a 1st and 2nd IF frequency and mixing them using the SA612 ic chip(s) Challenging for sure

    For anyone that wants top read up on the SA612A Specs(The SA612A is a Gilbert cell, an oscillator/buffer, and a temperature-compensated bias
    network ):

    https://www.nxp.com/docs/en/data-sheet/SA612A.pdf?
  • jmgjmg Posts: 13,615
    PropGuy2 wrote: »
    ...
    I am using the built-in synthesizer function in the Prop chip. It may be too noisy. In that case I will go to the SiLabs Si5351A chip. BTW some of those frequencies may be noisy also, it is not perfect. Reports are that the uBITX has "lots" of spirs.
    Any other ideas on a digital frequency synthesizer (chip or otherwise) are welcome. Remember that I am using a 1st and 2nd IF frequency and mixing them using the SA612 ic chip(s) Challenging for sure.
    A quick web scan suggests most spur-issues are harmonics/mixer artifacts, which is less a master clock generator frequency issue, and more a downstream linearity & filtering & PCB design one.

    The master generator issues will mainly be close in, and one symptom there is cleaner frequencies that are simple exact relationships to the master crystal & avoid fractions on the output dividers.
    The worst ones will be those not quite aligned, where the PFD filter cannot average well enough.

    There is no free lunch, and as you use fractional PLLs the average frequency is digitally set, but the Phase Detector is fed a dithered frequency to achieve that, and that results in ripple on the VCO.
    The overall consensus seems to be the Si5351a is 'good enough' even with these effects. It is a low cost solution.

    If you calculate the repeat frame of that PFD dithering, you know where to look for the close-in spurs.
    This link shows some PFD repeat of 200ns (aka 5MHz) spurs
    https://la3pna.wordpress.com/2016/12/31/si5351-spurius-preformance/


    Overall, the higher the internal VCO, the higher the PFD can be, and the less jitter results, and the better dithered PFD frequencies can be tolerated.

    Here is my table of Silabs i2c clock generators... where the VCO range and XTAL used are tabulated.
    The Si54x are fairly new, and have > 10GHz VCO's, whilst the Si570 has been around longer, and has a ~ 5GHz VCO, and there are comments on that on the web.
    As expected, a part with premium specs, does not come as cheap (or as low power) as a more modest spec, but none of these are prohibitive :)

    Device SpeedGrade Xtal     Output(MHz)  MinFvco(GHz)    MaxFvco(GHz)   Icc         Jitter
     Si549.A         152.6    0.2~1500     10.8            12.511886114    87mA CMOS   95fs RMS
     Si549.B         152.6    0.2~800      10.8            12.206718160    87mA CMOS   95fs RMS
     Si549.C         152.6    0.2~325      10.8            12.206718160    87mA CMOS   95fs RMS    $25/1+ ( >$8.36/10k )
     Si544.A          55.05   0.2~1500     10.8            12.550082103    74mA CMOS   150fs RMS   Si544: 1: $20.38 @ Mouser, 5 part codes.
     Si544.B          55.05   0.2~800      10.8            12.109728345    74mA CMOS   150fs RMS     ( >$6.69/10k )
     Si544.C          55.05   0.2~325      10.8            12.109728345    74mA CMOS   150fs RMS   
     Si570           114.28   10~160M      4.850           5.670           90mA CMOS   0.62pstyp   >$12/1  ONLY in 5x7 package
     Si514           31.98MHz 0.1~212M     2.080           2.500           21mA CMOS   0.8ps       DK : $7.53/1 (10MHz.3v3 & 24M.1v8)  >$2.71/10k  ($5.27/1k+) 5x7, 5x3.2, 2.5x3.2 sizes 
     Si5351A.MSOP10  25~27    0.002~200    0.6             0.9             22mA CMOS   ~70ps pp  ~85c/1k
     Si5351A.QFN20   25~27    0.002~200    0.6             0.9             22mA CMOS   ~40ps pp  ~$1.82c/1k  SI5351A-B-GM (QFN20 has lower jitter spec)
    
    
  • PropGuy2 wrote: »
    Bob VE1RRL - Yes that is the keypad. I use a paper overlay to redefine the keys, and the keys can be individually programmed to do what ever you want: VFO frequency, scan, read EEPROM, whatever you want. The uBITX uses a cheap mechanical encoder that will wear out in a few thousand cycles. Plus some of the uBITX functions are not very intuitive.
    I am using the built-in synthesizer function in the Prop chip. It may be too noisy. In that case I will go to the SiLabs Si5351A chip. BTW some of those frequencies may be noisy also, it is not perfect. Reports are that the uBITX has "lots" of spirs.
    Any other ideas on a digital frequency synthesizer (chip or otherwise) are welcome. Remember that I am using a 1st and 2nd IF frequency and mixing them using the SA612 ic chip(s) Challenging for sure.


    Here are some tests of the Propeller PLL phase noise. I haven't tested the oscillator on the FLiP. Most of the plots do not show the effects of the jitter that occurs when the divider is not a ratio of small numbers. 1/2N is perfect, 2/N and 3/N are often quite good, but using a large number in the numerator is problematic.
    forums.parallax.com/discussion/167895/fastest-dds-128-msps-and-fm-transmitter/p1 It seems that I have not yet posted the code for the 80MSPS version. I never finished the code cleanup because of low enthusiasm for the project, both mine and others.

    You can avoid a lot of phase noise by avoiding the Propeller PLLs and driving it with a crystal oscillator. Perhaps the DDS for first LO and then choose a second LO that's an integer fraction of the Propeller sysclock. I'm not sure if that would cause strange problems. If you think my DDS code would be useful, let me know, I can help with adapting it.

    It would be easy to port frequency generation from the P1 timer to the P2 Goertzel and get far better performance at the same time. The initial setup is a bit more complicated, but afterward it's just one instruction to set the frequency.
    James https://github.com/SaucySoliton/

    Invention is the Science of Laziness
  • @SaucySoliton
    Here are some tests of the Propeller PLL phase noise. I haven't tested the oscillator on the FLiP. Most of the plots do not show the effects of the jitter that occurs when the divider is not a ratio of small numbers. 1/2N is perfect, 2/N and 3/N are often quite good, but using a large number in the numerator is problematic.
    forums.parallax.com/discussion/167895/fastest-dds-128-msps-and-fm-transmitter/p1 It seems that I have not yet posted the code for the 80MSPS version. I never finished the code cleanup because of low enthusiasm for the project, both mine and others.

    Very interesting test you did. I still have to read it a few more times to even follow what you are doing LOL

  • @PropGuy2
    I will post pictures of this radio ( code named ACORN ) on this thread later. Also planning on setting up a booth at the Orlando HamCation, Feb. 8, 9, & 10th.


    Did you get it ready in time for the show? Do you have any pictures?

    Bob
  • PropGuy2PropGuy2 Posts: 214
    edited 2019-02-12 - 23:10:04
    I had a fantastic time at the Orlando HamCation 2019 show. About 20 thousand hams showed up for the 3 day event this past weekend (2.08.2019) The ACORN transceiver is still very much a work in progress. I try to knock out one design / software / layout problem everyday. Most of the parts are from DK. The PCB board I make in-house using Sprite PCB Layout software (from Germany) for Gerber & G-code generation. The actual PCB board is isolation pad milled using a ShapeOKO CNC table-top machine, with a very sharp Silicon Carbide Engraving bit. Here are some pictures from the hamfest.
    3378 x 3340 - 2M
    4413 x 1956 - 2M
    1789 x 1135 - 519K
    2939 x 2286 - 1M
  • 2019-02-12 - 19:09:07 edited 2019-02-12 - 19:10:04 Flag
    I had a fantastic time at the Orlando HamCation 2019 show. About 20 thousand hams showed up for the 3 day event this past weekend (2.08.2019) The ACORN transceiver is still very much a work in progress. I try to knock out one design / software / layout problem everyday. Most of the parts are from DK. The PCB board I make in-house using Sprite PCB Layout software (from Germany) for Gerber & G-code generation. The actual PCB board is isolation pad milled using a ShapeOKO CNC table-top machine, with a very sharp Silicon Carbide Engraving bit. Here are some pictures from the hamfest.

    Thanks! Ken(I assume it you in the picture) It looking really great. Interesting design also. Nice job on the VGA screen , it has the Prop 1 feel LOL
    I look forward to additional updates. :)
  • Yep - that's me W1HV, vanity callsign from way back when! It uses a FLiP module and showcases just about every hardware and software feature available for the Propeller chip. There are few commands and features that are NOT used. So far I have: Keypad & Iambic Keyer & Debug using FullDuplex Serial/ 4 Ports by Chip & modified by Moore, i2c functions by Gadd, for all the peripheral devices (RTC @DS3231, EEPROM and a lot more), Prop Synthesizer function for frequency(s), VGA driver with 32 user characters and color palette from Marko Lukat, microSD card & software from FSRW 2.6 by Rokicki & Dummer, and a whole lot of sweat & original glue to get it all working.
    EVERYTHING you see in these photos is hard fought design and layout, mostly by hand! The actual PCB, enclosure case, ACORN logo, signage on the wall, tablecloth, ad copy, Bill of Material, process sheets, baskets of software. Except for the big electronics companies, I was the ONLY other ham transceiver designer and manufacturer at the show.
  • jmgjmg Posts: 13,615
    PropGuy2 wrote: »
    ...Prop Synthesizer function for frequency(s)...

    What frequencies/precisions do you generate and how do you find that for Phase noise and spurs ?
    Did you compare with Si5351A ? (or a better sibling?)
  • I am looking at a 1st and 2nd IF synthesized frequency using a Prop function. As of now and until I have some time under my belt, I do not know about the the Phase noise or Spurs. I have the option of using the Si5351A chip if need be, but it has its problems also. I am open to other IC chips.
  • I started working on getting the original BITX working with a prop. Sadly i got stuck getting the SI5351 working with the prop so I didn't get far. I have a uBITX so would be happy to help if I can. The prop would be perfect for this application.
  • I started working on getting the original BITX working with a prop. Sadly i got stuck getting the SI5351 working with the prop so I didn't get far. I have a uBITX so would be happy to help if I can. The prop would be perfect for this application.

    That's great . Why not post your code and let us know what your having problems with . That way others can help. There have already been a few offers of help for this project and the prop.

    I just received a SI5351 breakout board to play with when I get time. I agree that the Prop1 or Prop2 would be great for this project.
  • Bob, I took a look and seem to have misplaced the code. I'll take a better look and dig out my SI5351 board. If you are interested in collaborating on a BITX/uBITX controller shoot me a PM.
  • The kit showed up today. Just a little over a month since I ordered it :)

    4160 x 2340 - 3M
  • Great!!! Now the fun begins. Putting it all together and with no magic smoke! BTW - I am interested in your first, and second, take on the uBITX transceiver. Hopefully you will not have as many problems as I have had. The ACORN radio (see above) is well on its way.
  • It has been about a month now - any comments on the uBITX ham transceiver?
  • I don't know where to ask this, but maybe someone here will know--

    Did I see a report here on these forums where someone was using a Prop pin to generate a signal for rudimentary 72 Mhz R/C transmission? I can't seem to find this through a forum search.
    I am the Master, and technology my slave.
  • jmgjmg Posts: 13,615
    The_Master wrote: »
    I don't know where to ask this, but maybe someone here will know--

    Did I see a report here on these forums where someone was using a Prop pin to generate a signal for rudimentary 72 Mhz R/C transmission? I can't seem to find this through a forum search.

    This one ?
    https://forums.parallax.com/discussion/169516/p2-controlling-27-mhz-radio-controlled-f150-toy-truck
  • jmg wrote: »

    Oh wow, I didn't know the pin toggled at the full 27 mhz, I thought it used a harmonic. I didn't even know Prop1 ouput pins could toggle that fast. (I'm not a Prop user) Thank you for the link
    I am the Master, and technology my slave.
  • PublisonPublison Posts: 10,852
    edited 2019-03-19 - 14:55:26
    The_Master wrote: »
    jmg wrote: »

    Oh wow, I didn't know the pin toggled at the full 27 mhz, I thought it used a harmonic. I didn't even know Prop1 ouput pins could toggle that fast. (I'm not a Prop user) Thank you for the link

    BTW the link was for a P2 thread, but it does have a link to Beau's RC Transmitter with a P1in this document on page 49:

    http://bscircuitdesigns.com/Misc/SPIN CODE EXAMPLES.pdf

    Infernal Machine
Sign In or Register to comment.