Category: uBitx News

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A processor upgrade – via a plug in to your Arduino Nano.

Here’s what the little Skunkworks from Jim N5IB in collaboration witih W0EB and W2CTX has been up to!

Jim says he has “A wee PC board that accepts a Teensy 3.5 or 3.6 processor, then plugs into the space that would have been occupied by a NANO”.

Corresponding I/O lines are routed to maintain compatibility with the uBITX. Since the Teensy has a RTC (real time clock) there’s a spot for its backup battery.

In principle, the adapter could be used to plug in a Teensy anywhere a NANO used to live. On a stock Raduino (you would have to remove the NANO and socket the space).  On an enhanced Raduino, such as the RadI2Cino (developed by N5IB/W0EB and W2CTX) it is simply a matter of inserting the plug.

The Teensy brings lots more memory, more I/O lines including lots of analogue ports, an on-card microSD slot, and of course a Real Time Clock.

The Teensy 3.5 runs on 3-6 volts, with 3.3V logic, but has 5 V tolerant digital inputs. The Teensy 3.6 also runs on 3-6 V, but its logic is 3.3V only.  It is faster and has more memory than the Teensy 3.5.

Prototype boards are in hand and will be beta tested within the next few days. Firmware portability is of course the thing that must be confirmed.

Jim promises to keep us up to date.

Reference
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Power curve flattening in the driver and pre-driver stage

Glenn VK3PE is attempting to flatten the power curve from the µBITx by playing with the driver and pre-driver stages. 

He has completed his mockup of the PA driver stages and

  • used MPSH10’s in all stages.
  • Used FT37-43 toroids all wound with 10 turns 0.25mm wire either tri- or bi-filar according to original Sch.
  • Bypassed all emitter resistors with a 220pF cap.
  • swept from C80 input to T10 secondary (as wound)

The result is a very flat response: better than 1db from 3Mhz to 54MHz.

Glenn plans to mock up the finals now to see what the net impact is on the power response curve.  If it is nice and flat he will replace the parts in the µBITx and we will have a solution that everybody who wants to flatten the power curve can use.

Reference
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What’s a safe operating voltage for the uBITx?

Bill Erickson asks, “Is it safe for me to use my current 13.8 v power supply on a ubitx, or do I need to pick up a 12 v 5a version?”

The answer is probably.   Many constructors have been using 13.8v supplies with the µBITx and the BITx40, and quite happily over a reasonable period of time.  The parts are generally rated to cope with 12v nominally, but this typically means up to around 14-16v.

There are components in the µBITx, however, that will not cope with more than 15v.  Some capacitors are 16v rated.  A component that is rated at a maximum voltage of 15v is the TDA2822.

Those of you with a WX version of the TDA2822 should be using a voltage regulator to reduce the voltage to 9v or less on this chip.   The chip is, otherwise, bound to fail.  Those with the FCI version needn’t worry so much, but may want to current limit (with a resistor) the output of the audio stage into speakers/headphones.

Reference
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uBITx FMSOS – Another new firmware branch for the uBITx!

Bob GM4CID placed a comment on our article “Ubitx modders are hard at work”  about another very interesting Raduino solution from BG1REN.   This can be found here:  https://github.com/qiwenmin/ubitx-fsm

The objective of BG1REN’s code (taken from the Readme) is “to implement a new firmware for ubitx, based on FSMOS. I am trying the FSM modal in this project, to verify that FsmOs is useful or useless.”

FSMOS is “a tiny and simple finite-state machine based embedded operating system. Currently, it supports Arduino and Linux/macOS platforms.”

Bob notes, “CAT commands use an Icom protocol and are well featured and Google translate does a good job with the Chinese documentation.”

Google  Translate says that the FSMOS implementation of the µBITx:

  • Supports LSB, USB, CW, CWR mode reception and transmission
  • Support VFO mode and channel (MEM) mode
  • Supports A and B dual channels
  • Support SPLIT, can operate in different modes
  • There are 20 memory channels, each channel can store the mode and frequency of A/B two channels, Split status and currently active channel
  • Supports manual keying (both mono and stereo plugs are supported) and paddles (optional Iambic A or B mode, and left and right hand modes)
  • Adjustable CW sidetone frequency, auto key speed, CW stop delay, key mode
  • You can set ITU zones (1, 2, or 3) to limit the frequency range that can be transmitted according to different zone settings
  • Support ICOM CI-V command, can use common software to operate radio, support Ham Radio Deluxe v5.24.0.38, WSJT-X, OmniRig, FlDigi, etc.
  • Supports automatic transmission from PC software
  • Supports the display of your call sign
  • Oscillator calibration function (10MHz transmit mode calibration or Zero Beat receive mode calibration) to ensure accurate frequency
  • Provides BFO calibration (CW and SSB calibration separately) to ensure optimal signal quality

The developer has drawn heavily on Ian Lee’s (KD8CEC) code and implementation concepts and acknowledges this. 

The screen display

After the boot information is displayed, the radio enters the home screen.  Ubitx-main

As you can see from  above, the main interface information mainly includes:

  • The most important information is displayed on the second line, including:
    • Channel mode: VFO mode or MEM mode. If VFO mode, V is displayed, and if channel mode, M is displayed.
    • Channel: The current job is A channel or B channel. The VA  (above) indicates that the VFO mode and A channel are currently selected.
    • Working mode: CW, CWR, LSB or USB. The CW mode is shown above.
    • Frequency: The frequency in the figure above is 7.023 MHz.
  • Status information and information for the other VFO are displayed on the first line, including:
    • Locked state: When the lock state is turned on, the frequency or channel remains unchanged when the knob is rotated, preventing accidental changes to the frequency or channel due to accidental touch of the knob. When lock is turned on, a lock icon is displayed in the upper left corner of the screen.
    • Split mode: The S character is displayed when split mode is on.
    • The middle and right sides show the mode and frequency of the other VFO.

If you start transmitting, the radio changes as shown below:

Ubitx-tx

In the main interface, the available operations are:

  • Rotate the knob: If the lock is not turned on, turn the knob to adjust the frequency (VFO mode) or change the channel (channel mode).
  • Short press the F button (press duration is less than 0.8 seconds): Enter menu mode.
  • Press and hold the F button (press for longer than 0.8 seconds, less than 1.6 seconds): Enter frequency adjustment accuracy mode.
  • Press and hold the F button (for more than 1.6 seconds): Turn lock mode on or turn off lock mode.

This new software option looks really interesting and many will probably be downloading the sketch to have a look at what it does!

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VE1BWV/VU2SPF firmware update to add CAT and SPLIT functions

JoeVE1BWV has announced that the team (Joe and Dr VU2SPF) have just released version 2.9U of their firmware to support CAT control  and split TX/RX operation particularly useful for 40m operations and contesters. The new code is available at http:// vu2spf.blogspot.ca

The team has  also been testing it with WSJTX FT8 mode and all is working quite well… Occasional episodes of rig time out appear to be related to limitations in hamlib.
See http:// vu2spf.blogspot.ca  for more details and instructions for downloading the updated sketch.
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uBITx modders are hard at work …

There are a number of very talented people involved in modding the µBITx.  A number of BITX20 IO group members have mods under way that we can look forward to hearing reports on in due course. This news item provides a bit of a round up of what’s in store for the µBITx constructor community.

Mods under development

Martin AE7EU, has been building and testing his Top Board for the µBITx. A lot of constructors are watching  Martin’s project with interest, because the top board would make the µBITx into a very compact (6″ x 6″x ~1 & 1/4″) high performing QRP TXCVR.

Nik VK4PLN, is experimenting with replacing the finals in the µBITx and has been giving us updates.  He has already told us how to use the ADAFRUIT TPA2016 I2C module as an AGC device and given us the required code.  He is in the process of offering a number of circuit boards (his RaduinoI2C – a Raduino replacement board, a similar board with a Teensy 3.2 on board, and LPF and BPF boards).

John VK2ETA, has already reported on his mic compressor  using the SSM2167 module, but is also working on an S-Meter,  an SWR/POWER meter, an Arduino pro mini linked by I2C to the Raduino to measure power, swr, and the final’s current (using hall effect sensor).  He also plans to control an ATU plus shutdown the final’s bias if required.  His ATU is an L-Network with 2 servos controlling a variable capacitor and a two wafer rotary switch to get 6 coil positions on high impedance and 6 on low impedance.

Glenn VK3PE, has been experimenting on improving evenness of output across all bands, by focussing on the response of the PA driver stages.  He is using MPSH10’s in his test board build and FT37-43 toroids wound as either trifilar, or bifilar, according to stage needs, of 10 turns each.  Comparing the original uBITX driver which has a ~7db less gain at 10M end, this version has ~2dB drop.

Andy KB1OIQ has made some really important mods that can be used by any constructor, but has also built in features for the white stick brigade (blind ops).   His firmware can be found here, but does require the addition of a number of hardware features including a matrix keypad, an I2C LCD display (to free up digital pins), and voice synthesis module (Emic2).
 

Jack Purdum W8TEE, an accomplished author and reviewer, and somebody who has previously released enhancement to the BITX40, has been working quietly in the background on something – possibly a touchscreen, upgraded processor and associated software?

Gerry EI8DRB, has been doing some playing around with the Teensy 3.2.  It will be interesting to see what he brings to light.

Bill K9HZ is working on an antenna tuner, but has already contributed the design of the full rig power control unit and his practical solution to the problem of uneven power output across bands.   He may well be working on other projects!

Mike, WA6ISP has contributed a range of Raduino replacement circuit boards and also developed a port expander to get over the shortage of µBITx I/O ports.  I suspect he is also working on other new hardware for the µBITx!

Jim W0EB and Ron W2CTX have provided hardware and software fixes for the CW keying issues, and in combination with the Radi2cino board they have developed restores I/O lines for other purposes.  They have plans for further software releases and have previously talked about including CAT control.

Ian KD8CEC has released his firmware variant with all sorts of features including CAT control, Memory Channels and IF Shift. The most recent beta version even includes built in WSPR (no computer required).  He has also produced his uBITx Manager PC/Linux software for EEPROM management for the uBITx and his hack of the WSTJ-X software for the Raspberry Pi provides almost complete control of the µBITx within WSTJ-X.   However, he has plans for a v2 firmware release in conjunction with hardware mods.

Dr. SP VU2SPF and Jo VE1BWV have already shown their stuff with a 2.7″ touch-panel controlled µBITx and a firmware release to go with it.  They are no doubt hatching up a few more mods right now!

Have I missed somebody cooking up a mod?

There are bound to be others lurking or that I have missed in summarising keen µBITx developers.   If you are working on something, drop me a line at info@ubitx.net to bring your developments to light.

Mike ZL1AXG

 

 

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Screen protector

Jeff, AD6RH, mentions that he protected his LCD screen from getting scratched by using a screen protector for an iPad (a screen protector for any other device would work) and cut it to fit.    He reminds you to clean the surface well before applying!

Reference
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Replacement to TDA2822 coming soon!

Sajid, VA3QY asked Ashhar Farhan where he could source a new and reliable TDA2822 audio chip.

Ashhar Farhan has replied, “I am working on an audio amp.  I am testing it live. I always personally use circuits on the air before recommending them. I hope that by Tuesday I will have something you can use.   About 100 out of 4000 boards have had this problem. and less than 20 of them have reported the blow out.”

Reference
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Second lot of Radi2cino boards available to purchase

Jim Sheldon, W0EB has announced that the W0EB/W2CTX/N5IB “RadI2Cino” (pronounced rad ee too CEE no) I2C replacement for the Micro BITX (uBITX) Raduino card is again available for purchase.

NOTE: these are only for the uBITX, not the BITX40 and other earlier models.

This board is designed to utilize either a 2 x 16 or 4 x 20 I2C LCD Display (not included) instead of the parallel display originally included with the uBITX so that the digital I/O lines formerly used by the display can be used to run the CW keyer and a few other functions in a much more efficient manner.

Prices have lowered a little since the first offering.

Partial kits with the IC’s soldered in place are no longer being offered.

Current options are:

  1. Bare Board (you supply the parts & you build it). $10 US shipping included. . International $15 US shipped.
  2. Complete Kit of Parts (less the Arduino NANO, LCD display and display I2C controller) – you build it. (All parts except the NANO, display and display controller are included in the kit.) $30 US shipping included.   International, $45 US shipped. All customs duties and VAT will be the responsibility of the purchaser.
  3. Completely assembled and tested RadI2Cino Including the Arduino NANO but less the display and I2C display controller.Assembled and tested RadI2Cino boards will be available by Special Order Only. They will require up-front payment by PayPal and up to a 1 week lead time to build and properly test) $75, shipping included in the U.S.

    No international orders will be accepted for assembled and tested boards at this time.

All orders will receive the complete assembly manual which includes a full bill of materials, full board layout diagrams and full schematics in PDF form via email.  This manual has also been attached here for your download:  RadI2CinoBoardConstruction. You can read through it and decide if it’s something you’d like to build.  The same manual will be included with the order by Email.

The bill of materials, included in the manual, has ordering information for the parts. Parts suppliers are Tayda, Digi-Key and Mouser.

Please, don’t post orders or info requests on the BITX20 list as Jim doesn’t always get the posts from the reflector.

Email w0eb (at) cox dot net for ordering or further information.

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Variable power supply

One of the discussions on the BITX20 IO list over recent weeks has been a variable power supply to control power out on different bands.   This seemed like the wrong approach to addressing variable output of the µBITx to the editor of ubitx.net (where the problem of inadequate drive or inadequacies in the PA design should be addressed directly) until he spotted this circuit diagram drawn up by Walter W9KJO, based on earlier suggestions.     It is simple and straight forward with the TIP142 device at the centre of the “buck” function.   24v input can be adjusted downwards to set the power output of the µBITx PA stage.

Walter says, “It controls voltage nicely. Really helps limit output power while working digital.”

However the TIP 142 really generates some heat.  He has a heat sink on the device, but the heat sink will need to be much larger to be safe.

Reference