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sbitx v3 issues

 

So I have had the board running for about a week. However, today I noticed that my output power is reduced, and the 4 drivers are very hot, with just power on, sbitx not started.
?I see nothing obvious. I would like some suggestions as to where to begin, as I have made the mistake of getting the board only (which I disagree with having no recourse with HF Signals, regardless of cause).?
?Any help would be appreciated.?
--
Mike - K8MCB?
 

Well, first I would turn the power OFF and let them cool a bit.

Then I would find a copy of the SCHEMATIC, and locate a voltmeter and other diagnostic tools

From MEMORY, I don't think there is power applied to those transistors when in RECEIVE, so I'd start the sBitx and see if there was voltage on their collectors.? ?If there IS and they get hot again, then yhou can start to diagnose WHY there is power applied to them.? ?They do run HOT when in normal transmitter usage.

That might get you STARTED, but this is going to be some work dealing with the schematic.? ?It is a process of breaking things down in to modules, dissecting which portion is doing somethin you?don't expect, and then figureing out why, over and over and over again.

Gordon KX4Z


On Sun, Feb 23, 2025 at 7:29?PM Michael Bales via <mikebales73=[email protected]> wrote:
So I have had the board running for about a week. However, today I noticed that my output power is reduced, and the 4 drivers are very hot, with just power on, sbitx not started.
?I see nothing obvious. I would like some suggestions as to where to begin, as I have made the mistake of getting the board only (which I disagree with having no recourse with HF Signals, regardless of cause).?
?Any help would be appreciated.?
--
Mike - K8MCB?
 

Yup -- they should not have collector voltage unless in transmit

See this post from me:? ?/g/BITX20/message/107311

I think I had Q101 get destroyed and then that causes a LOT of problems.? ?You may have to read around that message to understand it more.? ?Seems like I put in a protection resistor in my unit to prevent this damage.? ?I don't know if the same or similar issue has happened to YOU, but after you make some readings, you will figure out if that is what happened to you.....

Gordon KX4Z



On Sun, Feb 23, 2025 at 7:39?PM Gordon Gibby KX4Z via <docvacuumtubes=[email protected]> wrote:

Well, first I would turn the power OFF and let them cool a bit.

Then I would find a copy of the SCHEMATIC, and locate a voltmeter and other diagnostic tools

From MEMORY, I don't think there is power applied to those transistors when in RECEIVE, so I'd start the sBitx and see if there was voltage on their collectors.? ?If there IS and they get hot again, then yhou can start to diagnose WHY there is power applied to them.? ?They do run HOT when in normal transmitter usage.

That might get you STARTED, but this is going to be some work dealing with the schematic.? ?It is a process of breaking things down in to modules, dissecting which portion is doing somethin you?don't expect, and then figureing out why, over and over and over again.

Gordon KX4Z


On Sun, Feb 23, 2025 at 7:29?PM Michael Bales via <mikebales73=[email protected]> wrote:
So I have had the board running for about a week. However, today I noticed that my output power is reduced, and the 4 drivers are very hot, with just power on, sbitx not started.
?I see nothing obvious. I would like some suggestions as to where to begin, as I have made the mistake of getting the board only (which I disagree with having no recourse with HF Signals, regardless of cause).?
?Any help would be appreciated.?
--
Mike - K8MCB?
 

Mike,
?
I am not familiar with the board-only product, I assume the on-board finals, the 4x drivers you mention, are attached to some sort of heatsink or other means of dissipating heat in some manner, correct? I note the sBitx instructions for wiring up the board-only sBitx make no mention of adding/arranging for a heat sink or other such device, correct?
?
You say you had the board running for a week - I assume it worked fine, until it didn't, is that correct? Did you measure the output when you first used the board? How do those measurements compare with current output?
?
I assume your antenna system is unchanged, have you tested output into a dummy load?
?
As for the comment about HF Signals not providing a warranty/support for the board-only product, well, it makes sense to me, because there are so many possible issues when a random ham takes the board and starts adding to it to make it a complete, functional radio. The discount price reflects the lack of support, and HF Signals is very clear about not supporting the board-only product. I understand where you are coming from, but I understand their side too.
?
Sorry, I don't have any specific checks to make, hope this is helpful.
?
Ken, N2VIP
 

Also look at this message:? ?/g/BITX20/message/107307

If you have continuous 12V on the collectors of the drivers (which I think are also the case) then a pretty good chance you have toasted Q101 and or the 4905 or both.? ? That will give you continuous?+12.? ?There is a specific reason WHY this failure occurs, and some specific ways to prevent it.? ?You'll understand after studying those parts, if that was actually your problem.? ?it happened?to me.

gordon Kx4z


On Sun, Feb 23, 2025 at 7:53?PM Ken N2VIP via <ken=[email protected]> wrote:
Mike,
?
I am not familiar with the board-only product, I assume the on-board finals, the 4x drivers you mention, are attached to some sort of heatsink or other means of dissipating heat in some manner, correct? I note the sBitx instructions for wiring up the board-only sBitx make no mention of adding/arranging for a heat sink or other such device, correct?
?
You say you had the board running for a week - I assume it worked fine, until it didn't, is that correct? Did you measure the output when you first used the board? How do those measurements compare with current output?
?
I assume your antenna system is unchanged, have you tested output into a dummy load?
?
As for the comment about HF Signals not providing a warranty/support for the board-only product, well, it makes sense to me, because there are so many possible issues when a random ham takes the board and starts adding to it to make it a complete, functional radio. The discount price reflects the lack of support, and HF Signals is very clear about not supporting the board-only product. I understand where you are coming from, but I understand their side too.
?
Sorry, I don't have any specific checks to make, hope this is helpful.
?
Ken, N2VIP
 

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All has been tested through a dummy load, and transmitted into an antenna with no more than a 1.8:1 swr. Original output was within 5% of specified power. Now the output is down to roughly 60%( on most bands), it's slightly better on 80-40, at about 80%.?
?As far as being a "random ham" goes, I spent weeks researching the product before ordering, and have been extremely careful to stay as close to the recommended configuration as possible ( well regulated power supply, using a new pi 4 unit, use the supplied sd card and image, etc.). I understand the risk with open source and "hackable" hardware and software, but when it fails in its "intended" configuration, and you don't even get to start "hacking", something is amiss. I love the idea, but I feel that there should be a bit more backing by the manufacturer. Imo.






-------- Original message --------
From: Ken N2VIP <ken@...>
Date: 2/23/25 7:53 PM (GMT-05:00)
Subject: Re: [BITX20] sbitx v3 issues

Mike,
?
I am not familiar with the board-only product, I assume the on-board finals, the 4x drivers you mention, are attached to some sort of heatsink or other means of dissipating heat in some manner, correct? I note the sBitx instructions for wiring up the board-only sBitx make no mention of adding/arranging for a heat sink or other such device, correct?
?
You say you had the board running for a week - I assume it worked fine, until it didn't, is that correct? Did you measure the output when you first used the board? How do those measurements compare with current output?
?
I assume your antenna system is unchanged, have you tested output into a dummy load?
?
As for the comment about HF Signals not providing a warranty/support for the board-only product, well, it makes sense to me, because there are so many possible issues when a random ham takes the board and starts adding to it to make it a complete, functional radio. The discount price reflects the lack of support, and HF Signals is very clear about not supporting the board-only product. I understand where you are coming from, but I understand their side too.
?
Sorry, I don't have any specific checks to make, hope this is helpful.
?
Ken, N2VIP

--
Mike - K8MCB?
 

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I will take a look. Thank you!






-------- Original message --------
From: "Gordon Gibby KX4Z via groups.io" <docvacuumtubes@...>
Date: 2/23/25 8:04 PM (GMT-05:00)
Subject: Re: [BITX20] sbitx v3 issues

Also look at this message:? ?/g/BITX20/message/107307

If you have continuous 12V on the collectors of the drivers (which I think are also the case) then a pretty good chance you have toasted Q101 and or the 4905 or both.? ? That will give you continuous?+12.? ?There is a specific reason WHY this failure occurs, and some specific ways to prevent it.? ?You'll understand after studying those parts, if that was actually your problem.? ?it happened?to me.

gordon Kx4z


On Sun, Feb 23, 2025 at 7:53?PM Ken N2VIP via <ken=[email protected]> wrote:
Mike,
?
I am not familiar with the board-only product, I assume the on-board finals, the 4x drivers you mention, are attached to some sort of heatsink or other means of dissipating heat in some manner, correct? I note the sBitx instructions for wiring up the board-only sBitx make no mention of adding/arranging for a heat sink or other such device, correct?
?
You say you had the board running for a week - I assume it worked fine, until it didn't, is that correct? Did you measure the output when you first used the board? How do those measurements compare with current output?
?
I assume your antenna system is unchanged, have you tested output into a dummy load?
?
As for the comment about HF Signals not providing a warranty/support for the board-only product, well, it makes sense to me, because there are so many possible issues when a random ham takes the board and starts adding to it to make it a complete, functional radio. The discount price reflects the lack of support, and HF Signals is very clear about not supporting the board-only product. I understand where you are coming from, but I understand their side too.
?
Sorry, I don't have any specific checks to make, hope this is helpful.
?
Ken, N2VIP


--
Mike - K8MCB?
 

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Gordon,?
?So it would appear that the scenario you have experienced is precisely what has occurred in my unit. It's great that there is a fix. However I find it very disheartening that it happened in a brand new board and I am simply left to fix it myself.?
?Thank you for pointing me the right direction.?






-------- Original message --------
From: "Gordon Gibby KX4Z via groups.io" <docvacuumtubes@...>
Date: 2/23/25 8:04 PM (GMT-05:00)
Subject: Re: [BITX20] sbitx v3 issues

Also look at this message:? ?/g/BITX20/message/107307

If you have continuous 12V on the collectors of the drivers (which I think are also the case) then a pretty good chance you have toasted Q101 and or the 4905 or both.? ? That will give you continuous?+12.? ?There is a specific reason WHY this failure occurs, and some specific ways to prevent it.? ?You'll understand after studying those parts, if that was actually your problem.? ?it happened?to me.

gordon Kx4z


On Sun, Feb 23, 2025 at 7:53?PM Ken N2VIP via <ken=[email protected]> wrote:
Mike,
?
I am not familiar with the board-only product, I assume the on-board finals, the 4x drivers you mention, are attached to some sort of heatsink or other means of dissipating heat in some manner, correct? I note the sBitx instructions for wiring up the board-only sBitx make no mention of adding/arranging for a heat sink or other such device, correct?
?
You say you had the board running for a week - I assume it worked fine, until it didn't, is that correct? Did you measure the output when you first used the board? How do those measurements compare with current output?
?
I assume your antenna system is unchanged, have you tested output into a dummy load?
?
As for the comment about HF Signals not providing a warranty/support for the board-only product, well, it makes sense to me, because there are so many possible issues when a random ham takes the board and starts adding to it to make it a complete, functional radio. The discount price reflects the lack of support, and HF Signals is very clear about not supporting the board-only product. I understand where you are coming from, but I understand their side too.
?
Sorry, I don't have any specific checks to make, hope this is helpful.
?
Ken, N2VIP


--
Mike - K8MCB?
 

"As far as being a "random ham" goes, I spent weeks researching the product before ordering"

The "Random Ham" comment wasn't directed at you personally, it was a generalization of any potential buyer of the board-only product, sorry if my inartful statement rubbed you wrong - it wasn't my intention.
?
Ken, N2VIP
 

After checking the voltages at the points you described, it does seem to be the same issue with power delivery. Ironically, my week old v3 dies on the day I read about the v4, with the power issue addressed, being announced, and since I went with board only, I have to eat it. Live and learn I guess!
--
Mike - K8MCB?
 

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If you found the problem for real, hooray!

There is no guarantee the v4 will have protection for this. ? But YOU can put protection in on YOUR unit while doing the repairs. ? Allison had one solution; I think I picked a SIMPLE fix; read a bit before jumping in!!

This is much more like REAL “ham radio” part 97.1 than buying pricey perfect radios that are impossible to fix by yourself.?

Good luck!!

Gordon kx4z?



On Feb 23, 2025, at 23:26, Michael Bales via groups.io <mikebales73@...> wrote:

?
After checking the voltages at the points you described, it does seem to be the same issue with power delivery. Ironically, my week old v3 dies on the day I read about the v4, with the power issue addressed, being announced, and since I went with board only, I have to eat it. Live and learn I guess!
--
Mike - K8MCB?
 

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Yes, in this respect, you're correct that it's easier to diagnose, repair, improve, etc. Had I read the support group materials in its ENTIRETY, which isn't reasonable, I might have known to look out for this particular known problem and avoided it.?
?I do appreciate having a responsive support group to not only help solve the problem, but to also verify that the problem was inherent in the design and not something I caused.?
?Thanks again!








-------- Original message --------
From: "Gordon Gibby KX4Z via groups.io" <docvacuumtubes@...>
Date: 2/24/25 12:52 AM (GMT-05:00)
Subject: Re: [BITX20] sbitx v3 issues

If you found the problem for real, hooray!

There is no guarantee the v4 will have protection for this. ? But YOU can put protection in on YOUR unit while doing the repairs. ? Allison had one solution; I think I picked a SIMPLE fix; read a bit before jumping in!!

This is much more like REAL “ham radio” part 97.1 than buying pricey perfect radios that are impossible to fix by yourself.?

Good luck!!

Gordon kx4z?



On Feb 23, 2025, at 23:26, Michael Bales via groups.io <mikebales73@...> wrote:

?
After checking the voltages at the points you described, it does seem to be the same issue with power delivery. Ironically, my week old v3 dies on the day I read about the v4, with the power issue addressed, being announced, and since I went with board only, I have to eat it. Live and learn I guess!
--
Mike - K8MCB?

--
Mike - K8MCB?
 

Michael,

Although HFsignals doesn't offer warranty on the V3 board-only kits, we do offer technical support to help you diagnose and fix any problems you may encounter. Please send us an email at support at hfsignals dot com and we will do our best to help.?

73
--
Support@...
 

Hi Michael!!
?
I sincerely hope that you're able to figure out and fix your issues on the FIRST try -- it took me some MONTHS on a used unit; I probably CAUSED some of the failures, and Ashhar and others were a BIG help.??
?
No design is perfect.? ?I don't know how many or what percent of units fail due to some "gotchas" in the circuit.? ?It happened to me; Allison pointed it out; it may have happened to you, and I think there may have been another.? ?If our guess is correct, over time, there may be some more of these failures, and therefore some busted units showing up on EBAY until the word gets around how to fix 'em.? ?Unfortunately a lot of ham radio land needs to GROW A BIT in "fix it skills" so there will be some gnashing of teeth associated.? ? ?I had HEATHKITS to start off MY ham radio career, and THEY had design issues that both bedeviled me, AND GREW ME UP with a new skillset in electronics.??
?
OTHER THINGS TO FIX:? ?WHILE YOU ARE IN THERE (easy to fix some of this by adding a little SMT resistor tee-pee'd or otherwise in series -- there are some OTHER THINGS you may want to fix as well --?
?
====================================
SEE THIS NOTE: ? /g/BITX20/wiki/36110
====================================
?
?
There I tried to document all the busted diodes that likely *I* caused in my unit, but they still blew.? ?An errant probe can easily blow diodes that have no series resistance when they connect directly to +12!? ? I would encourage you to fixe those while you're there, because the diagnosing of problems in the complicated band-switching T/R circuit is truly difficult for people like me!!? ?When I finally understood what an amazing circuit Ashhar had created to do all that....well it took me a long while.??
?
I'm not a manufacturer or quality inspector guy and no one so far knows the prevalence or incidence of these issues.? HF SIGNALS may or may not decide to add a bit of protection; who knows?? ?They have all kinds of very complicating sourcing and manufacturing issues to solve, way way way beyond me or the vast majority of us.? ? ?I have a friend who accidentally hit the PTT button on a baofeng that didn't have an antenna on it and POOF-- no more transmitter.? ? Every design is a compromise; you cannot include protection against EVERYTHING.? ?
?
Hope you get that rig working great and have all kinds of fun with it!? ?I'm in the throes of trying to learn how to create a 64-bit disk and their new software and see if I like it, or need to add in some of the special features that I put into my 32-bit version.? ?This is part of the fun of the vast hobby.
?
73
Gordon KX4Z
?
?
 

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There are those of us who, by choice or necessity, are "appliance operators".? I have medical problems that don't allow me to do the things I used to do.? My years are catching up with me (81 of them on Wednesday).

Gerry Sherman

Sent by the Windows 11 Thunderbird

On 2025-02-24 12:46, Gordon Gibby KX4Z via groups.io wrote:

Hi Michael!!
?
I sincerely hope that you're able to figure out and fix your issues on the FIRST try -- it took me some MONTHS on a used unit; I probably CAUSED some of the failures, and Ashhar and others were a BIG help.??
?
No design is perfect.? ?I don't know how many or what percent of units fail due to some "gotchas" in the circuit.? ?It happened to me; Allison pointed it out; it may have happened to you, and I think there may have been another.? ?If our guess is correct, over time, there may be some more of these failures, and therefore some busted units showing up on EBAY until the word gets around how to fix 'em.? ?Unfortunately a lot of ham radio land needs to GROW A BIT in "fix it skills" so there will be some gnashing of teeth associated.? ? ?I had HEATHKITS to start off MY ham radio career, and THEY had design issues that both bedeviled me, AND GREW ME UP with a new skillset in electronics.??
?
OTHER THINGS TO FIX:? ?WHILE YOU ARE IN THERE (easy to fix some of this by adding a little SMT resistor tee-pee'd or otherwise in series -- there are some OTHER THINGS you may want to fix as well --?
?
====================================
SEE THIS NOTE: ? /g/BITX20/wiki/36110
====================================
?
?
There I tried to document all the busted diodes that likely *I* caused in my unit, but they still blew.? ?An errant probe can easily blow diodes that have no series resistance when they connect directly to +12!? ? I would encourage you to fixe those while you're there, because the diagnosing of problems in the complicated band-switching T/R circuit is truly difficult for people like me!!? ?When I finally understood what an amazing circuit Ashhar had created to do all that....well it took me a long while.??
?
I'm not a manufacturer or quality inspector guy and no one so far knows the prevalence or incidence of these issues.? HF SIGNALS may or may not decide to add a bit of protection; who knows?? ?They have all kinds of very complicating sourcing and manufacturing issues to solve, way way way beyond me or the vast majority of us.? ? ?I have a friend who accidentally hit the PTT button on a baofeng that didn't have an antenna on it and POOF-- no more transmitter.? ? Every design is a compromise; you cannot include protection against EVERYTHING.? ?
?
Hope you get that rig working great and have all kinds of fun with it!? ?I'm in the throes of trying to learn how to create a 64-bit disk and their new software and see if I like it, or need to add in some of the special features that I put into my 32-bit version.? ?This is part of the fun of the vast hobby.
?
73
Gordon KX4Z
?
?
 

On Mon, Feb 24, 2025 at 04:46 AM, Gordon Gibby KX4Z wrote:
====================================
SEE THIS NOTE: ? /g/BITX20/wiki/36110
====================================
?
?
You know, I check this feed many times a day and this is the first I have seen this. I will have to look into this a little bit closer, thanks for the post Gordon.
?
?
Joel
N6ALT
 

Hope it helps, Joel.? ?
There are some "gotchas" in the circuitry of the used V2 that I bought.? ?Adding a few protective resistors will prevent all the issues that I either had, or caused myself!

Gordon


On Mon, Feb 24, 2025 at 11:22?AM Joel Caulkins/N6ALT via <caulktel=[email protected]> wrote:
On Mon, Feb 24, 2025 at 04:46 AM, Gordon Gibby KX4Z wrote:
====================================
SEE THIS NOTE: ? /g/BITX20/wiki/36110
====================================
?
?
You know, I check this feed many times a day and this is the first I have seen this. I will have to look into this a little bit closer, thanks for the post Gordon.
?
?
Joel
N6ALT
 

Hi Gordon again,
?
I was just looking at my V2 board to find the spot in the note, I was using a lighted magnified glass and made a startling discovery, my V2 board is 100% hand soldered, even all the SMD stuff, I thought all of these boards went through a pick in place process. Some of the soldering is horrible, like the sI5351, I'm not sure why it even works but it does. Did you notice whether yours is 'hand made'? I know my two V3s are factory built.
?
Joel
N6ALT
 

Joel,
It makes sense the board was hand soldered, one of the drivers behind the creation of HF Signals is to provide meaningful piece work to Indian mothers/women, so as far as I know every radio/product offered by HF Signals is hand assembled in India.
?
Farhan spoke about this a long time ago, but it hasn't been mentioned here in a while, and new members of the community might not be aware of that.
?
More information can be found on their website:
?
https://www.hfsignals.com/index.php/about-hfsignals/
?
Ken, N2VIP
 

Hi Ken,
?
I'm far from being a new member, I've been here since the very first Bitx came onto the seen. Most all radios HFSignals has produced are NOT?hand assembled, only the coils and final transistors and other things that can't be done on a pick place machine are done by hand by the women of India, that is why I was surprised to find my V2 completely hand built. It's just odd but okay, I have built a lot of SMD kits that require all SMD parts to be soldered by hand so I know it can be done. I believe the latest V3.02 boards are mostly computer assembled except for toroids, etc.
?
Joel
N6ALT

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