uBitx News – Page 11

February 26, 2019February 26, 2019

History of designs leading to the v5 uBITx

The following list of circuit designs has been compiled by Tom KF5NWC:

Minima

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). 🙂

link to schematic

Ubitx v1

Continuing on with the general receiver concept with lessons learned from the minima, the uBitx was published.

link to schematic

uBitx v2

No schematics are known to have been published.

uBitx v3

The version 3 schematic is the version of the first production board from HFSignals.com (formally hfsigs.com).

link to download

uBitx v4

link to schematic on HFSignals

c210 and c216 – are listed as 0 pf and are not present on the board used in production by HFSignals.
Q942 and Q952 – are not populated on board sold by HFSignals. As sold by HFSignals, the final drivers for the PA are IRF510. These alternative pads allow experimentation such as replacing the IRF510’s RD15HVF1’s which are a different pinout.

uBitx v5

link to download

c210 and c216 – are listed as 0 pf and are not present on the board used in production by HFSignals.
Q942 and Q952 – are not populated on board sold by HFSignals. As sold by HFSignals, the final drivers for the PA are IRF510. These alternative pads allow experimentation such as replacing the IRF510’s RD15HVF1’s which are a different pinout.

Reference

February 23, 2019February 23, 2019

JackAl

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.

Reference 1

Reference 2

February 19, 2019March 2, 2019

BITeensio card beta firmware released

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.

Reference

February 17, 2019

Antuino kitset coming

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:

https://github.com/afarhan/antuino

February 17, 2019February 27, 2019

V5 uBITx board in production

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 :

The LM386 is back as the audio amplifier (like in the BITx40. All hail the cross-over distortion sickness!
The IF is now 11.059 MHz. These 68pF crystals are easily available, with a pretty good 2.7 KHz band pass. As their frequency is away from any spur of 16 MHz and 25 MHz (the two crystal oscillators on the Raduino) there will be no spurs.
The relay switching scheme is different. The 30 MHz LPF is now always on, the individual LPFs for lower bands are switched in or bypassed (by default). It is easily understood in the circuit diagram
The CW wave-shaper uses a 1 uf capacitor in place of 0.1u, this reduces the key-clicks.
The circuit now uses BFR93W in the 45 Mhz IF amps, for more overall gain in the TX lineup.
A 470pf in the emitter degeneration of pre-driver instead of a 0.1uf gives more gain at 28 MHz than 3.5 MHz.

Reference #1

Reference #2

February 17, 2019February 17, 2019

Toroid winding hints

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).

Reference

February 17, 2019February 17, 2019

Ashar talks about the BITx world

There is a long segment interviewing Ashhar Farhan, inventor of the uBITx (and in fact the whole BITx series of radios). He talks about the release of the v5 board, future plans, etc. Ashhar notes that around 20,000 boards have been manufactured to date! He is also planning to bring out an antenna analyzer kit with a number of additional features.

Reference

February 17, 2019March 3, 2019

uBITx.net has been out of action

Regular visitors will have observed that uBITx.net has been out of action. The gap started with a vacation, and a quiet spell over Christmas and New Year. However, Mike ZL1AXG has had some health issues. Posting will commence again now, but it will take a while to catch up!

Note that older list posts will appear as back-dated items in December, January and February so as to appear in the correct sequence on this website. That means you may have to look back a few pages to find some real gold. This BITX20 list signal to noise ratio has been falling since a peak in around March 2018. More and more constructors are discovering the joys of the µBITx, but new ideas are harder to uncover amongst all of the postings!

[EDITOR]

February 15, 2019February 27, 2019

Cleaning up the output of a uBITx by putting an LPF on the raduino output

Jim AB7VF made some measurements of CLK0 ouput (from the SI3571a chip on the Raduino board) and concluded that it would be helpful to filter the output.