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Re: #zbitx RX delay makes difficult CW unusable
#zbitx
Thanks, Gordon! El dt., 15 d¡¯abr. 2025, 23:10, Gordon Gibby KX4Z via <docvacuumtubes=[email protected]> va escriure:
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Re: #zbitx RX delay makes difficult CW unusable
#zbitx
¿ªÔÆÌåÓýNo, I¡¯m sorry, I can¡¯t be more specific. The issues are difficult and lots of people are working on them. Eventually, they will come up with better and better solutions just as we did with the previous radios. ? I know it¡¯s disconcerting, but that¡¯s the way it is with bringing new radios to market. The flex people had egg on their face for a very long time!!Gordon kx4z? On Apr 15, 2025, at 17:00, Mikel EA5IYL via groups.io <mikel.forcada@...> wrote:
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Re: Fixed: cw latency and wsjtx/flidigi sidetone
As a followup, I put some scope probes on my keys, a ubiquitous Bencher and a Code Warrior.? The 2nd has magnetic return which seems very slow.?? It was very difficult to get a contact that was less than 10 ms.??? 10 ms was in the range of contact bouncing.??? With most key contracts were in the range of 50 ms it makes me wonder how anyone can send fast.? Perhaps some of the high quality keys are faster than mine.
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It may be a matter of sending style.? Of the zbitx keying demo's I have watched, the op's are using the dual paddle like a single paddle and not using a squeeze technique.?? Dit and Dah memories are a feature of most keyers and they are helpful for the single paddle style.? ( see the article I posted a link to earlier in one of these CW threads ). |
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Re: #zbitx RX delay makes difficult CW unusable
#zbitx
Could you please be more specific to convince me?? Mikel L. Forcada / Alacant / l'Alacant¨ª / Pa¨ªs Valenci¨¤ mikel.forcada@... El dt., 15 d¡¯abr. 2025, 22:43, Gordon Gibby KX4Z via <docvacuumtubes=[email protected]> va escriure:
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Re: Homebrew satellite control system that can run on sBitx
Thanks, Juan, that's great advice!
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Today I finally solved a mystery -- the "buttons" that I put on the board for manual control of Elevation were not working correctly.? ?Everything else worked!? ?Computer control was excellent.? ?Buttons?? All screwed up.
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TURNS OUT that A6 and A7 cannot be used as DIGITAL INPUTS (the others can) -- and I had used A6 and A7..... so I had to rewrite a tiny portion of K3NG's lower-level read routine to properly read ANALOG inputs from these buttons, convert to "HIGH" or "LOW" -- and now even the buttons work correctly.
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HOORAY!? ? Now I have to learn all the OTHER stuff about how to use the ICOM 820H and control it properly and maybe I'll actually be able to make a contact -- and now I think (at least receiving on 2 meters) I have the transverter/sBitx option ALSO reaching workability state.? ?
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Everything is a series of steps.? ?You build something, find an "issue", fix it, and then move further.? ?The same with the zBitx.? ??
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Gordon KX4Z
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Re: #zbitx RX delay makes difficult CW unusable
#zbitx
Don't worry -- it will get better!!
Gordon KX4Z
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Re: Transmit power
Yes sir,
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That is the fix for my problem. I put the 30 amp supply in line and now get 20 watts on 20 meters. I was planning for the worst case and total relief. I put the Drive at 25 and keep under the QRP limit.
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Oh, and I noticed that the max draw was 6 amps.
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Thanks again and can't wait for the encoder board to arrive.
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73,
Dean/ N2TNN |
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Re: Transmit power
¿ªÔÆÌåÓý
I'm on a V3, but when I TX using the test tone on 40M it's pulling ~7.5A at 13.6V.? Normal use case (like FT8) will be closer to the 6.5A number you are seeing.? Best to get a supply with some head room so you don't stress it too much.
Jeff
From: [email protected] <[email protected]> on behalf of Evan Hand via groups.io <elhandjr@...>
Sent: Tuesday, April 15, 2025 12:18 PM To: [email protected] <[email protected]> Subject: Re: [BITX20] Transmit power ?
On Tue, Apr 15, 2025 at 02:12 PM, Jeff Duce wrote:
My radio at full power draws nearly 8A. Jeff,
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Is your radio a V2 that is still capable of 40 watts? My V3 uses less than 6.5 amps for 25 watts, the max for a V3.
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73
Evan
AC9TU
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
The Si5351a is primarily made to drive logic (relatively high Z). Driving low Z loads will pull the output levels out of their saturated 3.3v output which causes further non linearites. At high loads there are common internal current paths which cause further non linearites.
A high Z load is preferred. Something like a high? value resistor 470 driving a MMIC and 3 dB pad, or a logic gate suitable for driving mixer? |
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Re: Transmit power
Dean,
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I should have mentioned that you can operate the sBitx with your power supply. I suggest setting the transmit drive so the voltage starts declining and backing down a little on the drive. That is the maximum that you can get with your current power supply.
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73
Evan
AC9TU
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Re: Transmit power
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> on behalf of Dean, N2TNN via groups.io <N2tnn@...>
Sent: Tuesday, April 15, 2025 11:59 AM To: [email protected] <[email protected]> Subject: [BITX20] Transmit power ?
GM all,
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I have been reading and enjoying the sBitx V3. I have seen some references to output power of the rig to be above 5 watts. I just read the technical data and "Maximum power output of 40 watts on 80M and 40M bands, goes down to 20 watts on 15M" was stated.
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I have the sBitx powered with a 13.8 v 4 amp power supply. I have an auto tuner in line. The tuner oled will show power out and swr.
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I set the Drive at 49 and key down, tuner ---> 4 watts
??????????????????????????? 75 and get????????????????????????????? 7.6--> 5.2---> stopping at 4.7 watts
??????????????????????????? 100 and get???????????????????????????? 11--->? 5.3----> stopping at 4.7 watts
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All other bands as about the same. Drive at 49---> 5 watts? Drive 100---> 10w then drifts down to 5 watts.
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I get nothing like the specs indicate. I am usually running QRP so its not a big deal but something is wrong.
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Dean/ N2TNN
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Transmit power
GM all,
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I have been reading and enjoying the sBitx V3. I have seen some references to output power of the rig to be above 5 watts. I just read the technical data and "Maximum power output of 40 watts on 80M and 40M bands, goes down to 20 watts on 15M" was stated.
?
I have the sBitx powered with a 13.8 v 4 amp power supply. I have an auto tuner in line. The tuner oled will show power out and swr.
?
I set the Drive at 49 and key down, tuner ---> 4 watts
??????????????????????????? 75 and get????????????????????????????? 7.6--> 5.2---> stopping at 4.7 watts
??????????????????????????? 100 and get???????????????????????????? 11--->? 5.3----> stopping at 4.7 watts
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All other bands as about the same. Drive at 49---> 5 watts? Drive 100---> 10w then drifts down to 5 watts.
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I get nothing like the specs indicate. I am usually running QRP so its not a big deal but something is wrong.
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Dean/ N2TNN |
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Re: zBitx +-2 MHz transmit spurs? --> SHOWSTOPPER for transmitting
I've examined the schematic and I do have one concern about the 3.3V regulator feeding the SI5351; I noticed that there is not a cap on the input side of the chip, and only a 0.1 uF on the output side. I do note the the manufacturer Data Sheet shows a lot more capacitance on both sides of the chip (10 uF on the input and 22 uF on the output). Is it possible that the lack of caps there is causing the regulator to misbehave, with potential problems for the Si5351?? I mention this because KB1GMX (Allison) has pointed this out as a problem on linear regulators before.? Lee KX4TT
On Tuesday, April 15, 2025 at 01:14:07 PM EDT, Gordon Gibby KX4Z via groups.io <docvacuumtubes@...> wrote:
Thank you so much for doing that research!
one solution is series filters consider adjusting the idle current on the final Mosfets to see if that has any effect
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I wonder where the signal is coming from?
maybe we could attack it there??
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gordon kx4z?
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#zbitx RX delay makes difficult CW unusable
#zbitx
I was playing with an up-to-date Zbitx a while ago, trying to chase CW stations calling in 20m and 30m and I noticed that after a few minutes of the kind of CW sending that is possible now (the timing makes CW hard at 18 WPM, as many have noticed) one starts to hear an echo of what one sends, a couple of dits later. I was using an adjustable antenna, and I saw that the RX response to my adjustments to it also came a couple of dits later; disconnecting the antenna seemed to mute DX some split seconds later. All of this clearly points at some kind of RX delay building up, maybe because of processor load? After resetting, it seems to work fine for a while.
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After a couple of weeks of playing with this radio, which I intended to be one of my SOTA radios, I'm quite disappointed. Any of my Chinese cheap SDX radios is much better at CW than the Zbitx. |
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Re: zBitx speaker noise?
#zbitx
I noticed similar noise If i tune to any freq, I hear chugging noise. If i go to the menu or any where there is no waterfall displayed, the noise disappears. So for me it is the water fall causing the noise. A simple solution which would help is a button to turn or off the water fall. Other shielding might help, but trun off water display makes a huge?difference. Thanks. Joe? VE1BWV? On Tue, Apr 15, 2025, 7:02?a.m. HA3HZ via <gyula=[email protected]> wrote:
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Lee
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