Getting prepared for the JackAl

Some of you are waiting with baited breath for the JackAl Board, announced by Jack W8TEE.   You can get yourself geared up for the JackAl by pre-purchasing some of the kit required, as it is due to be released shortly.  You will need a colour touch display panel, a Teensy 3.6 processor and associated Teensy audio board.

Display panel

There are two display options for the JackAl board: 5″ or 7″.  Neither is likely to fit in your existing µBITx enclosure, so you may also want to purchase a new enclosure.

The panels can be purchased from Their order numbers are:

ER-TFTM050-3 (5″)
ER-TFTM070-5 (7″)

Both displays use the following options:

4-wire SPI interface
Resistive touch
No font (the library is being used for fonts)

Both are 800×480 displays using the RA8875 chip. If you run the samples using a touch screen, make sure you run the Calibration sample program first.

Teensy 3.6 and audio board

The Teensy 3.6 and its associated audio board can be purchased from the manufacturer’s website or from other sources.


JackAl Board

Now you can have a look at a partially populated JackAl board thanks to this photo from Jack W8TEE in response to a question about a LA4425 as a replacement to the TDA2822.

The highlighted square in green is the audio amp stage of the JackAl board: a 7W TDA7266M.  Seems like you could really blast the neighbours with that one!

In case you haven’t figured out what the JackAl board is about: it is a supplementary board that hsould be released in the next few weeks by Jack and Al, that adds a Teensy 3.6 processor, and a number of other mods, all on one board.  The Teensy will give the µBITx new features like DSP.

JackAl is here!

Jack W8TEE and Al AC8GY have  released details of the JackAl board following FDIM (preceding Dayton Hamvention).

Friday night is a sort of Show-and-Tell at FDIM and they used that opportunity to show their JackAl board in action. The photo above shows a little more about what it is and does.

At the show, Al hooked up a noise generator to the µBITX to show how the filters work. (There are 4 preset filters for CW and 4 for SSB.) In addition, you can customise one CW and SSB filter to the bandwidth you desire. You might be able to see that the skirts are pretty steep for the filters on the scope in the background. The setting of the CW custom skirts are set differently, in that you pick a centre frequency (e.g., 700Hz in the shot below), press the encoder, and then you see this:

In this case, turning the encoder CCW increases the bandspread (i.e., the 440 red number above, although it looks orange in the photo) by simultaneously moving the skirts (480Hz and 920Hz) further apart. If you turn the encoder CW, you narrow the bandspread. Most CW users will probably center the bandpass on their favorite sidetone frequency, which centers the bandpass on that frequency.

The demo used a 5″ display, although a 7″ display is also available. The third knob on the front is for a second encoder that we use for everything from setting the CW keyer speed to adjusting the filter skirts. You can see some of the plots on the panel at the rear of the picture above for some of the board’s features (e.g., filter responses, compression, etc.) Those will be included in the documentation when the (downloadable) manual is finished.

The JackAl board has the following features:

  • 5″ or 7” touch screen 800×480 TFT color display
  • Dual VFO’s
  • RIT
  • S meter
  • RTC
  • CW keyer, 5 to 50wpm (we could go up to 100wpm, but…really?)
  • Up to 50 CW preset messages, selectable at runtime…perfect for contest messages
  • Touch screen function and control selection (e.g., band changes, RIT, mode, VFO, VFO increment, LSB/USB, etc.)
  • Automatic LSB/USB selection based on frequency (overrideable)
  • One touch frequency increment changes (1Hz to 1MHz in multiples of 10…the white underscore in the frequency window)
  • Dual encoders (frequency, features)
  • EEPROM storage of user preferences (one-click reset to “factory” defaults)
  • Uses Teensy 3.6 processor (1Mb flash @180MHz) and companion audio board
  • Support for 3 external CW push button switches (NO) for sending stored CW messages (e.g., contesting)
  • Hardware AGC using IF take-off
  • Audio AGC with adjustable threshold
  • Mic compressor with adjustable threshold
  • 8 band audio equalizer
  • Receive audio filter: 48dB/octave (8 pole equivalent DSP filters)
  • 4 CW presets (150, 300, 400, 600, [or none] Hz 3dB bandwidth) + 1 user-defined knee frequencies (at runtime!) filter
  • 4 SSB presets (1500, 1800, 2200, 3000, [or none] Hz 3dB bandwidth) + 1 user-defined knee frequencies (at runtime!) filter’
  • Variable Notch filter, encoder adjustable, use specified Q
  • 7 watt power amplifier

The board will be distributed with all (surface mounted) parts in place. The user must supply the Teensy 3.6 ($30), its supporting audio board ($15), and the 5″ ($34) or 7″ ($44) touch screen displaying (using the RA8875 controller chip,

We expect the JackAl board to sell for $50.

We may need to adjust this price as we have only received “ballpark” cost estimates for the board since we only have the Gerber files for the Beta board.

Currently, we are using less than 20% of the available flash memory (out of 1Mb) and less than 15% of the SRAM (256K), so there is plenty of memory resources available for adding “stuff”. The board also brings out a number of I/O pins to help your experimentation. With the exception of removing one SMD resistor on the µBITX board and soldering two wires to those pads, all interconnections are via existing connectors.

Our best guess is that after finishing the modified Gerber files, production, Beta testing, and writing support manuals, it will be probably two months before we begin distribution. We will announce its availability here as soon as we can. BTW, if anyone knows a high-quality PCB manufacturer who also does pick-and-place at reasonable prices, we are getting quotes and would like to know about them.


W8TEE JackAL Board at FDIM

Jack W8TEE provides a bit more insight into the JackAL board that uses the Teensy 3.6 to give lots of processing grunt.

Jack suggests that he and Al were going to put an SWR meter on the JackAl board, but have backed away from it for this iteration. The main reason was because of the board size. The nano-acres it would take on the board would raise the PCB cost above the 100x100mm size to do it right for the possible power levels that might be involved. That doesn’t mean you can’t add one…

The good news: Right now, there are about a dozen “empty” pins available on the board for experimenting.  They are currently using less that 15% of the 1MB of flash memory and less than 10% of the 256K of SRAM.   That includes code space for some features that we’ve coded for (e.g., a RTC) but have not implemented yet (e.g, adding a button battery to power the Teeny’s RTC in sleep mode).

The Teensy is a 3.3V device, so we have an onboard regulators for 5V and 3.3V. Al and Jack think this will up the “fun level” for hackers considerably…at least that’s our intention.

The bad news: They got caught in some kind of Chinese holiday and other “delays” to get the PCB. Al ordered the board since he did all the work on the EE design. It seems our Beta PCB order got pushed to the back of the line.

When Jack wrote to them and pointed out that he was disappointed with their service, especially after ordering more than 1000 boards from them last year, the order suddenly went from “In line” to “shipped” in under 24 hours. They received the board this week and discovered errors on the board (2 from the design team, 1 from the manufacturer of the board).  The Beta board will have some “hairs” on it.

Jack and Al will be demoing JackAl at FDIM, but not all of the features will be implemented. The order for the new board will be sent this week.  We’ll immediately send it to our Beta testers and then make it available via an announcement on the BITX20 list.

Al and Jack look forward to seeing uBITx constructors at FDIM!