Arlo KD9HLC says “I’m sure somebody’s already done this…”
Well maybe some have talked about it, but the picture shows you how easy it can be!
The All-band HF Amateur Radio Transceiver: Just waiting to be modified
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Arlo KD9HLC says “I’m sure somebody’s already done this…”
Well maybe some have talked about it, but the picture shows you how easy it can be!
Ian Lee KD8CEC has been busy releasing his Version 1.01 sketch for the uBITx. However, he has also been busy with modding the wsjt-x Linux software to do some amazing things with the uBITx.
He has now announced the release of version 0.5 (Beta) of Wsjtx-Portable.
For those who are not familiar with wsjt-x, this software is a general purpose graphical user interface (complete with waterfall display) for digital HF modes. The software is a great product, and is available in Windows, Linux, and MacOS flavours to cover every amateur operator’s PC set up. What is more, if you have installed KD8CEC’s V1.01 uBITx sketch, this includes Hamlib CAT functionality so WSJT-X will work with your uBITx on all of those digital modes.
So what is WSTJX-Portable? This is a modified version of WSJT-X that is designed to be used on a Raspberry Pi and a 3.5″ TFT touch screen.
Did you want a nice compact touch screen for your uBITx, but don’t want to hack your uBITx enclosure and push your Arduino Nano to the limits? Then here is the answer! The uBITx is controlled by the Raspberry Pi via the 3.5″ touch screen. You can dial up a frequency, set the step value, change band or mode, go to TX or RX, etc. right from the touch screen. Quite a feat!
Mitani Misaru JE4SMQ’s ubitx has been built in an ORIGAMI paper case (15 cm square) which cost just 100JPY(about US$1).
Mitani did not use an Encoder with a push switch but substituted a separate push switch for the encoder button switch.
Ver1.00R software has been installed and modified as follows:
1. The uBITx transmits on the Japanese Amateur bands only. If you tune out of the band the PTT/CW Break In simply doesn’t work. This is required to meet Japanese regulations.
2. The BAND Select mode follows the Japanese Band Plan.
3. In CW mode the Mic PTT is used for keying. This is always in straight key mode. If a Paddle is connected the keyer can be used by adjusting the menu menu setting.
Henning Weddig DK5LV says he is in the process of using an op amp and SSM2166 on his “original” BITX40 as a way of achieving an audio AGC function.
This op amp has a gain of 10 (20 dB) and an audio AGC system. He purchased a pcb from ZL1CVD with the DIL chip via ebay years ago. Unfortunately ZL1CVD does not sell this pcb any more…
The SSM2166 has a dynamic range of 60 dB, the opamp in front of it is intended to replace the first discrete amplifier after the demodulator and will amplifiy the audio into a range the SSM2166 can handle. The SSM2166 has a provision for outputting an AGC voltage (an RMS output) and this may be able to be used for driving an S-meter.
Others are thinking along the same lines. For example, Glenn VK3PE says:
“I’m thinking along the same lines. I built a Mic amp version using the SSM2167 and thought it might work also for the Receiver. It’s essentially the module seen on ebay but I’ve added a level pot on the output side.”
Meanwhile Alex PA1FOX comments:
“I am using the AGC from the original uBitx design, but found the time constant of 1uF and 100k to be far too low. This makes it a very fast AGC, not producing a nice sound with voices. I changed to 1.5 uF and 4M7 and now stronger stations are nice and clear (they ‘push’ the noise level down ) and the gain comes up nice and easy when the QRG is clear. I think I’ll keep it this way.”
Anders SM5NNO has drawn attention to a published fix for low levels of drive on SSB with BITx transceivers from Mr K P S Kang (VU2KR / VU2OWF) on this blog. While the mic gain fix relates to the BITx40, it translates readily to the uBITx.
André PA3EIV confirms that the above fix (by Mr. K P S Kang VU2KR works 🙂
He changed the value of R65 to 4K7 and the value of R63 to 10 Ohm using 1206 surface mount components (desoldered from scrap prints).
He now has, on normal voice volume, 10 watt’s out on 20m. RV1 is turned counter clockwise for about 75%. André uses a Baofeng microphone.
K P S Kang VU2KR / VU2OWF has an item on his blog showing an RF AGC for BITx designs. The AGC is apparently very effective at calming those 9+20dB signals that on the uBITx will damage your hearing!
The design is for the BITx40, but can be readily adapted for the uBITx – probably not at the antenna (because it is best to avoid diodes at the front end of the uBITx), but at the 45MHz IF stage. Are there any takers to adapt this design for the uBITx?
Sajeesh VU3PSZ shows off his new uBITx case design alongside his older BITx40. A nice pair of rigs. His blog item shows all the details, including a home made jig to achieve the folds in the aluminium. This is definitely worth a look if you are considering a home-brew aluminium case for your uBITx.
Vic WA4THRI always enjoy seeing how others have built their BitX’s and has pointed out ideas that others might find useful:
1. Almost everyone places their tuning control to the right, but if you place the Raduino to the right you can easily update and play with the software by just plugging your computer into the USB port [EDITOR: With a penetration on the right hand side wall of the enclosure for insertion of a mini-USB-B connector.]
2. It is hard to beat the value of the Banggood EF01 instrument case. If you turn it upside down and eliminate attaching the hard plastic feet you have a smoother mounting surface for circuit boards and can use the vent holes for a speaker grille. Add some stick-on soft plastic feet on the “new” bottom.
3. Using the second line of the BitX display to label switches and controls saves having to find a way to place labels on the front panel.
Andy KB1OIQ has posted a file on the [BITX20] IO Group files page: kb1oiq_i2c_mod.pdf that describes the hardware and software modifications that he performed on his uBITX to free up digital pins on his arduino. You will need to be logged in to the Group page to access the file.
Andy converts the LCD to use the I2C bus, thus freeing 6 Arduino digital pins for other uses. Only very minor modifications are required to the Raduino sketch (and you will need to install a different library). He documents every step involved with photos. Well done!
[EDITOR Comment – removal of the two pull-up resistors on the additional board and direct connection to the I2C A4 and A5 ardunio pins should suffice without use of a level converter board. However, the cost of adding in the level converter is negligible and will work well!]
The website contains information on how to download the code.
Next : New Feature – Working on adding CAT Control
Joe VE1BWV subsequently uploaded the connection diagram to show how the Arduino Mega 2560 connects to the display, the si5351a and the main board.