Sunil markets an AGC kit on his website. John NQ3RP asked group list members whether they had success with this kit. It appears that some have.
There are schematics & the adjustment procedure in the files on the BITX20 IO Group list.
Ian KD8CEC has announced a beta version of his firmware (Version 1.12) for the uBITX V5 board. He has written an article about it here.
All existing firmware functions for V3 and V4 are available on the V5 beta.
The same version of uBITX Manager will work with the v5 Board.
Only the LPF control and the frequency control part are changed in the V5 code. Ian has released firmware V1.121 for V5.
Alison KB1GMX counts 5 different schematics for the µBITx, and that is not including the HF1 or minima (2014) designs that came before the µBITx. The design was evolutionary.
The first production boards were labelled “V3”. Two further iterations have been sold since, the “V4” and now “V5”.
V3 and V4 are probably technically not fully compliant with emissions regulations in most countries (at least in the developed world). However, the low power output of the µBITx probably means that emissions will have resulted in few issues with interference in practice.
The effectiveness of harmonics, IMD and spur modifications incorporated in the V5 board have yet to be established across a selection of production boards. There are no doubt improvements, but the degree to which the product could be considered to be 100% compliant on all bands and all modes has yet to be established.
[Edited by uBITx.net]
Jim Sheldon W0EB has done some initial testing of the new µBITx board on his brand new spectrum analyser. The results are CW only (so these results won’t show the impacts of any distortion in the mixers or IF bidi amplifiers that were observed with the v3 and v4 boards.
There are still some bands that would not meet most countries’ spectral purity requirements.
For a full set of graphs for each band click on the reference link below.
The following list of circuit designs has been compiled by Tom KF5NWC:
A large group of enthusiasts worked with Farhan to create and test a general coverage receiver and multi-band transmitter called the Minima. Its simplicity, innovations such as its KISS mixer, shuttle tuning using a potentiometer, and overall low build cost inspired hope of an affordable multi-band transceiver (to me anyways). 🙂
Continuing on with the general receiver concept with lessons learned from the minima, the uBitx was published.
No schematics are known to have been published.
The version 3 schematic is the version of the first production board from HFSignals.com (formally hfsigs.com).
For those who are not following the email list, during the gap in coverage on ubitx.net in January, Al and Jack launched their JackAl board that adds a lot of features to the µBITx.
The hardware is compatible with the µBITx v5 board, but requires different firmware. More details on JackAl will be added to the website with a January posting date shortly. Check back in the list of posts, as I am backdating information to provide a better history for constructors visiting the site.
Jack is going to be at Hamcation in Orlando. If you see a shirt with the picture of the JackAl display on the back at Hamcation, then stop and say “Hi!” to Jack W8TEE.
Jim Sheldon W0EB has announced that the Triumvirate Skonk Worx (TSW) has published their latest “beta” 2.8″ or 3.2″ Color TFT touch screen firmware for the BITeensio controller card. This new firmware addresses the changes Farhan made to the uBITX in the release of his Version 5 transceiver board. This board is now shipping from HF Signals.
Using the BITeensio card in combination with the new firmware means constructors will now have the capability of selecting operation with either the older V3 and V4 uBITX boards which we are calling “Legacy” boards or the new Version 5 ones via an item in the “Calibration” menu.
Depending on which type of uBITX it is installed in, the one time calibration will be required for that uBITX board.
Calibration data is stored on the BITeensio’s Micro SD card in different locations for the 2 different versions so if you calibrate the card in a V4 (or V3) radio, and later decide to switch it to a V5 radio, you will have to again calibrate it for the V5 system. However, once that has been done, you can then swap the BITeensio back into your original “Legacy” radio, select “VL” in the calibration menu and it will recall the previously stored calibration data for that version. If it’s the same VL board you originally used for “VL” calibration, you should not have to re-calibrate the card. If, however, you install it in a different uBITX than the original one, you may have to touch up the calibration to make things sound right and operate on the right frequency. The same is true for V5 boards.
Since both of the displays (2.8″ and 3.2″) use the same ILI-9341 controller, and have the same number of pixels, no software changes are needed to change out the display. No user action is required to switch from one to the other except to make sure they are cabled properly and this is outlined in the manual.
The operating manual for this software has been completely re-written to reflect the changes and the pictures have been changed to show the operating information in the new version.
You can find complete information on this (and other items from TSW) on their website.
Ashhar Farhan has foreshadowed his upcoming Antuino design. This is a modern replacement to the Sweeperino he designed much earlier on. The Antuino uses an arduino nano and an si5351a (both can be found in the µBITx) and the crucial RF part – an AD8307.
Details can be found here:
Ashhar Farhar reported on 6 February 2019 that HF Signals has pushed the uBITx v5 into production. An initial 100 boards had arrived so they may run out quickly (reminding us of the v3 board shortages of 2018).
Note that HF Signals website has not yet been updated.
See the scans on https://groups.io/g/BITX20/album?id=84174.
The new Arduino firmware and the schematic can be found here: https://github.com/afarhan/ubitx_v5/.
The direct link to the schematic is here: https://github.com/afarhan/ubitx_v5/blob/master/ubitx_v5.pdf
The new firmware breaks backward compatibility with the previous firmware as the Intermediate Frequency is now 11.059 MHz and the relay switching is different. Probably, is it is possible to patch the new code to switch between the two LPF relay switching schemes as well as the IF with some #define statements.
The new ‘features’ are :
Mark N7EKU/VE3 has found the calculator on toroids.info to be very accurate — so much that he rarely measure after winding anymore. Toroids.info quotes a quite generous length of wire to use (even considering the 1″ leads) so he usually subtracts an inch.
No need to re-wind if you loose count. As long as you have a cell phone or other digital camera, just take a picture and then zoom in on it. It becomes very easy to count if you do that.
How to wind: first put the wire through the center, gather the ends, and pull them taut. Now wind one half of the windings, and then the other. This way you only have to deal with one half the length of wire at a time (instead of threading the entire length through for the beginning turns).