On Sep 25, 2023, at 15:55, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:

?

My homemade microphone with a -24DB rated Mic cartridge work just fantastic. Able to get full power output with my normal voice with just a little bit of a close setting. ?I have three remaining cartridges from digikey, ?so lots of high power output mics I can make in the future. ?I bet in a year or two I’ll find the original mic that I lost….

The sBitx V2 that I purchased without the pi, got turned on for the first time today. Added power poles to the incredibly thick and wonderful power cables, and also added in my homebrew design polarity protector (P channel MOSFET system)?

turned it on with a little bitty wall wart 12 V power supply just in case, and all went just wonderful.

I might mention that I heard a tiny rattle inside when it first got unboxed after having been shipped to the original owner and then shipped again to me. ?(So TWO shippings) What fell out was a tiny bit blob of solder. ? Very glad to have found that! ??

after I do some more testing on it (in original factory condition), I plan to try and add Zener protection on the final MOSFETs, and also change out the Mica insulator for aluminum nitride.?

VERY impressed with the case and mechanical design of this unit. Great job, Ashhar! ?Fits together like a glove. Took me a bit to get the DSI cable into the pi with my less-dexterous ?fingers — but success! ? Thinking about putting up a whole new antenna for myself 100 m away from my 2 WINLINK ?24/7/365 gateways so I’ll get to do more ham radio myself!!

gordon kx4z?

On Oct 22, 2023, at 13:18, rose@... wrote:

?At the request of Ashhar I'm posting this here.

Original message:?

Rose,

I was told by the sales that you are having trouble with your sbitx. As we mentioned in our manual as well as the website, the place to ask and quickly get help for the radios is by joining our mailing list. If you click on /g/BITX20/join, you can join us in a minute.

Let me take a few minutes to explain, why the help is through the group and not a regular support by email etc. The sbitx is an open source radio. For instance, it is the ony radio in the world that supports FT8 mode without needing an external computer. The FT8, in turn, has been developed by Dan Tayloe, W1JT, a Nobel laureate. If someone runs aground with FT8, much of the protocol details are not even fully understood by me (I wrote the sbitx core). We need help from others who understand those parts better.

The sBitx is an SDR, and as an SDR, almost everything is controlled by software. The sBitx software is open source, which makes it do so many things that a normal radio won't. This also means that it is being actively developed by a number of hams who don't work for us. They are all active on the bitx20 group.?

The second reason for asking help in the group is that almost every conceivable problem has been voiced and resolved in the past emails. When you post a query, others just look up prior fixes to it and you the collective wisdom of the group quickly resolves the issues.

Now, about your issue itself.

1. You have referred to two mics. What make and kinds are these mic? Is any of the mics supplied by us? The sbitx mic needs the tip to be connected to the mic's +ve, the ring to the PTT and the sleeve to the ground.

2. You mentioned the sidetone. it can be adjusted clicking on settings button on the left column of the user interface, this will bring up the settings that includes the sidetone volume.

3. You output power does appear to be low. I would want to know the current draw when receiving and when you try transmitting on LSB with mic gain set to 1 and drive 1 and without any speech into the mic. This will measure the idling current on transmit without any modulation.

Do post the outcome of #3 to the group and we will take it up from there.

My reply:

Ashhar,

It is good to hear from you, but I have been promised help for the past few weeks.

I was really behind the concept of the radio and I understand but I excepted some kind of out of box experience with at least a minimum level of functionality. Why should I not contact the manufacturer if the thing I've purchased literally hasn't worked since day 1 out of the box. I can understand it in terms of future development and participation.

1. Yes I have used two mics, the original one provided and also a new one wired up in the same manner. A similar styled fist grip mic. I have recorded the sound from both in audacity, the one that was supplied does sound really tinny by comparison and has to be gained right up to hear anything.

In software I was having to gain it up to 70-100 just to get any output at all. My new mic worked better but I've tested so many things it isn't totally consistent. My email chain has more detail.

2. Yes I am aware sidetone is adjustable, and I have tried it, it sounds awful. Like I can hear the peaks of my voice and that is it. It's choppy and incoherent. This matches with the report only contact that actually ever responded to me using this radio.

3. The radio is currently boxed up again as I had not heard anything since around the 5th. And had zero progress, again after being promised multiple times of having resolutions.

But at idle at 13.5v I was drawing around 800mA. And at transmit I'm pretty sure it was around 10A but that was with tone or voice. I'll have to set it up again to gather these results as you have asked but I am away for a couple of days. Though I'm fairly sure it was in a similar range.

I have had constant issues with the radio, it has not worked since I received it.

To answer question 3. In LSB with drive 1 and nothing going into the mic the draw was 1.5A at 13.5V

On Oct 22, 2023, at 10:35, Gordon Gibby via groups.io <docvacuumtubes@...> wrote:

?Thanks Evan. Yes we need confirmation. One way or the other. Either I’m doing something wrong, or my unit is a complete fluke, or there’s a problem!

I’m not sure why anyone would bother developing software for a radio that might not be legal to operate…..

What if ?only 25% of the units have a problem? But that still way way too high!! ? This is a groundbreaking transceiver and it should not be troubled by these kinds of problems. ?We certainly fixed them on the developer unit. ?And my measurements there may have been clouded by the Heathkit Cantana so it may be even better than I know! ?

The bypassing issue I think is important for the 470 ohm resistors. ?Only c204 protects at that end —-Adding several more may help. Also between the 470 and the indconductors may help

It’s dicey to slow down the switchover with capacitors on the 470 K. ?Theoretically, into a 50 ohm system, the 470 K alone provides better than 60 DB isolation. ?So I’m not sure a lot needs to be done there. Maybe a few picofarads? ?The output of the RF voltage doubler has a few hundred picofarads already. ?so it provides some significant isolation. ?

I think the real issues are the +12 line, where RF energy can get back into earlier stages and wreck havoc as far as spurious responses there, !!!!! and maybe just maybe on the ground line itself which I hope is solid. ?

The QDX seem to show that it’s possible to fix all of this. But we’re running a lot more RF current through those diodes than it did. ?I don’t know if we need additional diode’s in parallel at the output, I just don’t know. ?? A text jig fixture and a good clean commercial transceiver might be able to prove this— run the RF through a turned-on 1N4007 and measure the spurious response afterwards; this would also be a way to select preferred diodes ?for this service

I’ll be back to Gainesville in about 10 days and then I may be able to start measurements again. ?

I don’t know how many other people have quality test set up such as the Siglent or Rigol spectrum analyzer‘s but we could sure use some data; as my finances allow I’m going to buy a higher power RF pad so I can easily tolerate the full output for some time. ??

Thanks for your thoughts!

Gordon?

On Oct 22, 2023, at 07:15, Evan Hand <elhandjr@...> wrote:

?Gordon,

If it is passed through on the bias circuit, would adding some capacitors help?? Every connection of the bias to the LPF circuit may need to be bypassed.



This might mess up the filters instead of helping.

So far, you are the only one that is reporting an issue.? It would help if others verified that there is an issue with other V2 sbitx or for HFSignals to respond with measurements from the production units that have been tested.

73
Evan
AC9TU

On Oct 22, 2023, at 09:15, Aaron K5ATG <Aaron@...> wrote:

?Thanks for the replies.?
--
'72

Aaron?

On Oct 22, 2023, at 07:15, Evan Hand <elhandjr@...> wrote:

?Gordon,

If it is passed through on the bias circuit, would adding some capacitors help?? Every connection of the bias to the LPF circuit may need to be bypassed.



This might mess up the filters instead of helping.

So far, you are the only one that is reporting an issue.? It would help if others verified that there is an issue with other V2 sbitx or for HFSignals to respond with measurements from the production units that have been tested.

73
Evan
AC9TU

I am hoping that someone could help me out and provide me with a link on where I can purchase a Baofeng microphone. I'm referring to the one that comes with the uBITX, the hand microphone that looks like it is for an HT but it has just the one pin instead of 2 pins.?
Thank you
--
'72

Aaron?