Hi all, In my uBitx v6, I am trying to do CW keying from a PC through serial port. For this I used DTR line from PC and used optocoupler to couple the CW port in radio like below: Problem is it works for first few word sent, then TX latches up to ON continuously. I disconnected the input line from PC, then also TX remain in ON. Then I connected the O/P line only to radio and kept the I/P line disconnected, power cycle the radio and set the CW mode to enable from radio. After 30 sec or so, the TX again comes to ON automatically. This indicates problem is in the O/P circuit that connects to radio. There is noise somewhere that puts the photo-transistor in conduction mode automatically without any input. But how this is happening ? Thanks

Error in Sound Input I got the above error message while using sbitx with an external hdmi monitor and the jtdx program. The built-in RPi4 has 4GB of memory. I've been using the device in this configuration for a few days and occasionally I get this message, which I can eliminate by restarting. My audio settings are: input: plughw:CARD=Loopback, DEV=1 mono output: plughw:CARD=Loopback_1,DEV=0 mono Maybe my audio input setting is wrong? I am sure that I have output when I have the above output settings. When the error message appears, it still works, the sound does not drop. -- Gyula HA3HZ

I've been using it with this modification for a few days. The idea to look for a solution in the hardware was given by the fact that the error message came immediately after switching it on. Then I started following the hardware signal reception process and compared it to the factory datasheet and came to this solution. I still use the settings referring to LAG reduction, but now I'm more confident in setting a higher volume and a higher IF (incoming signal sensitivity) level. I also don't reduce the BW, as is stated in the recommended settings. Here's the solution: -- Gyula HA3HZ I made the shielding with self-adhesive copper foil, on which I glued Kapton tape as an insulator. Both tapes are 50mm wide, about 30 cm are needed. --eof

It is difficult to find a description for jtdx, and what is there was written 6 years ago. Fortunately, the description already addressed the slow PC problem and included an automatic RX filter. The next step is the LAG problem, which is only visible with jtdx, because when the number of stations in the audio track exceeds 30, there is little time for decoding. How little time is left can be read in the description at https://en.wikipedia.org/wiki/FT8 Out of the 15 second period, 12.64 seconds are the transmission time, leaving 2.36 seconds for decoding. It is understandable that with a large number of stations this can only be done with a fast PC. What can someone using the RPi do? My experience shows that the Lag value is at most -0.55 seconds / 0 stations or -0.50 / 2 stations. This is constantly changing. So our device takes 1.8 seconds to operate. There is not much we can do: - set the decoding functions to reduce LAG. (some settings need to be changed, experiment) - select option 3 from the Autoseq options and do not forget to set the Auto RX frequency filter accordingly. - since there is little possibility to reduce the signal between the radio and the jtdx input, keep the IF and volume values ​​low. - another option is to reduce the receiver BW - you need to learn to use the auto RX Filter, check from time to time that when you want to monitor the band, the filter is turned off. In the receive window, the activated state of the filter is gray. - I think that the time between the end of the transmission and the start of the next period is 15 - 12.64 = 2.36 sec. When I excluded the other stations with the RX filter, I saw the best Lag value of -0.55 / 0. The remaining time is 2.36 - 0.55 = 1.81 seconds that our device uses, this is the time lost from decoding. I am curious if this time could be shortened? What does our device use the 1.81 seconds that it loses from decoding for? Does anyone know the answer? -- Gyula HA3HZ

Hey all, I'm trying to run wsjt-x natively in the sBitx_v3 by following the directions in the "sBitx V3_Hello Manual_V1.0" who's link I got from HFSignals. Seems to work ok, cat control changes frq's etc. The time displayed in the app is UTC (I assume) since it is exactly 7hrs ahead of my local time in AZ (UTC-7). I have the app set to decode only (no tx) but I get nothing, except the "decode" button lights up blue here and there... My antenna is a Chameleon F-Loop V3 tuned to the 20M wspr freq. using a RigExpert stick with an SWR of 1.04 Looked around in the group messages but nothing came up that would help me, so any help would be great... Thanks

Looking for responses and opinions on what people are using for reverse polarity protection on the sBitx? -JJ

Hi, Sorry to reopen an old thread. I modified my uBITX V6 to use a Nextion display, but I happen to be reusing the original TFT display for another project. The display may not be operating under the recommended voltage conditions on the uBITX V6. On the TFT module I received, jumper “J1” was closed, which means the on board 3V3 regulator is bypassed. Extracts from the Touch Sensor IC (XPT2046) and LCD Driver IC (ILI9341) datasheets are shown below. XPT2046: ILI9341: On the UBITX V6 (Raduino) PCB, the power supply to the TFT module is 5V and the signal levels from the Arduino are 5V. The ILI9341 is being operated above the absolute maximum supply voltage limit and there is a risk of damage occurring. If jumper J1 is open on the TFT module, the supply voltage to the IC's will be regulated to 3V3, but the interface signals ideally need to be level shifted to 3V3. 73, Dave

I just received the Panadapter kit to add to my uBitx V6 radio. Along with the Panadapter I also got the I-F Buffer which is needed to connect the Panadapter to the uBitx. The installation is simple, just 6 solder connections to connect the I-F Buffer to the radio, then a coax with SMA connectors (which come with the I-F Buffer) to connect it to the Panadapter. I used a 3D printed case from files downloaded from the website. This makes a great addition to the uBitx radio. It’s nice to see other activity on the band and tune right to it. The span is selectable from 16 KHz to 192KHz Luca (IW2NDH) has a U.S. rep so shipping is quick. Mine arrived in approx 4 days via USPS. Here is the website for more details. https://jackdev23.wixsite.com/panadapter

When I was working with my transceiver in ~106F temperatures last month, there were some obvious heat issues with the RPI with multiple applications loaded. I bumped into the thermal throttling threshold a few times. Even at home it's running in the 70s or 80s depending on what's running and I run it all day lately. Anyways, I figured that I'd crack mine open and try to mitigate that a bit. I typically run my RPIs in standalone cases with active cooling of some sort. Probably not wise to place a fan right next to the transceiver. I found that I was able to apply the RPI 4's 'OEM' set of heat sinks with the room afforded us between the PI and the transceiver board. I thought that I was going to have to mill off some of the aluminum material on the sink for the CPU because of the crystal directly below it but there's about ten thousandths between the heat sink and the xtal. The default heat sinks appear to have decreased the average temps by about ten degrees F. Hopefully, I won't have to try this out in those high temps again but with an external fan blowing in from the side these heat sinks may help mitigate the heat a bit more. I have a DC blower fan that I'll try at some point. Which reminds me, I need to print or build a battery holder for the back. Anyone know of any STLs for that? I figured that I'd share. Just an FYI.