Re: Capacitor on irf510 sbitx
Great going Gordon , hope these lessons continue to it's logical conclusion.
It'll surely help someone and me offcourse.
de VU2UPX?
On Tue, 31 Dec, 2024, 1:47 am Gordon Gibby KX4Z via , <docvacuumtubes= [email protected]> wrote: OK?
1.? I’m assuming you were able to adjust the idle current with the bias potentiometer and get expected results. If not, then there could be a DC disconnection somewhere in the power amplifier stage.
2.? Those four metal cans to the left of the power amplifier stage are the driver stage. They should get pretty warm or even hot within 15 seconds if you put the radio into any single side band mode and key the microphone. Even if you don’t say anything. If they don’t, then there is some problem with the DC connections to the driver stage.
3.? Do you have any other means to measure the output of the transmitter? A SWR meter or anything similar? If so, try to get some kind of a read on whether there’s any real power coming out even if it is only 100 Milli Watts or so. ??
Do you hear anything in another receiver tune to the same frequency? Usually, you’ll hear something if there’s any real power out put
4. ? Do you have a voltmeter?
? It receives fine. I can hear everything that it should with an antenna.
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When I transmit in any mode I see that it looks like it is transmitting on the screen but it shows 0 watts and 1.0 SWR. Doesn't matter what mode I transmit on.?
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Re: Capacitor on irf510 sbitx
OK?
1. ?I’m assuming you were able to adjust the idle current with the bias potentiometer and get expected results. If not, then there could be a DC disconnection somewhere in the power amplifier stage.
2. ?Those four metal cans to the left of the power amplifier stage are the driver stage. They should get pretty warm or even hot within 15 seconds if you put the radio into any single side band mode and key the microphone. Even if you don’t say anything. If they don’t, then there is some problem with the DC connections to the driver stage.
3. ?Do you have any other means to measure the output of the transmitter? A SWR meter or anything similar? If so, try to get some kind of a read on whether there’s any real power coming out even if it is only 100 Milli Watts or so. ??
Do you hear anything in another receiver tune to the same frequency? Usually, you’ll hear something if there’s any real power out put
4. ? Do you have a voltmeter?
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On Dec 30, 2024, at 15:00, bretnemeth via groups.io <bretnemeth@...> wrote:
? It receives fine. I can hear everything that it should with an antenna.
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When I transmit in any mode I see that it looks like it is transmitting on the screen but it shows 0 watts and 1.0 SWR. Doesn't matter what mode I transmit on.?
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Re: zBitx features SWR / Power meter
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Re: Capacitor on irf510 sbitx
It receives fine. I can hear everything that it should with an antenna.
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When I transmit in any mode I see that it looks like it is transmitting on the screen but it shows 0 watts and 1.0 SWR. Doesn't matter what mode I transmit on.?
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Re: Capacitor on irf510 sbitx
We all understand!!? ?
1.? Does it RECEIVE?? ?If you put an antenna on it, do you HEAR recognizable signals?? ?? 2.? What exactly does it do when you try to transmit (specify mode, and what you see on the screen; for example, if you tell it you are in CW and have a paddle, and press the mic button, you should see a string of dashes or dots flying past.? ?
Gordon
That's a bit over my head. I would rather buy a new board than go that deep. I'll dig around a bit but if it requires equipment I don't have it's over.
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Re: Capacitor on irf510 sbitx
That's a bit over my head. I would rather buy a new board than go that deep. I'll dig around a bit but if it requires equipment I don't have it's over.
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Re: Capacitor on irf510 sbitx
time to break out the oscilloscope or build an "rf probe" if you don't have one, so you can begin to diagnose with a simple $6 digital voltmeter. Lots of learning opportunities!? ? There are some charts (Somewhere on all the amassed knowledge base) of typical signal levels and voltages, that will help you.......
Took me MONTHS to solve a thorny problem with one of my units (which I might have been the cause of, so not blaming anyone else)
Gordon KX4Z
One of the legs broke on one diode. So I ordered more. Only problem is I put everything back together and set the bias. Still no power out. Starting to think I blew another fet or maybe there is a software problem. I have read about some peoples radios not working due to software.
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Re: Capacitor on irf510 sbitx
One of the legs broke on one diode. So I ordered more. Only problem is I put everything back together and set the bias. Still no power out. Starting to think I blew another fet or maybe there is a software problem. I have read about some peoples radios not working due to software.
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Re: Capacitor on irf510 sbitx
On Sun, Dec 29, 2024 at 03:10 PM, bretnemeth wrote:
i was reading they should show some continuity
in one direction.
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For what it's worth, they are right that standard diodes have some continuity measured in one direction and nothing in the other direction. TVS diodes like the ones used in the sBitx V3s don't show any continuity at all unless you apply more than 18.5V then they conduct, so if yours are not showing any continuity they are probably okay. It also doesn't matter what direction you install them, they are not polarity sensitive like a regular diode. If you have them I would install them, we can use all the protection we can get with the final MOSFETs. It wont hurt anything.
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Joel
N6ALT
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sBitX V3 Microphone input
I’ve been trying different microphone combos with the microphone input and the thing is — I can’t figure out how to get the PTT on the mike line to work (running Dexx’s 4.2 btw).
The ring on the connector seems to trigger PTT when the signal floats, which I can get from just touching a wire connected to the ring. A normal PTT is a ground — what does this ring need to see? a specific voltage? is it sensing a resistance level? ?I note it seems to be running -2.4V…grounding doesn’t work… how can I trigger it from a button?
Or are there other ways to trigger PTT?
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With some mikes like my motorola, the PTT simply connects the audio circuit, so I’d like to be able to sense that and send a trigger to the PTT.
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Re: Operating FT8 from a different country
#sBITX_v3
On Dec 30, 2024, at 16:14, HA3HZ <gyula@...> wrote:
On Mon, Dec 30, 2024 at 01:08 PM, Support HF Signal wrote:
This bug exists when you try to enter the callsign from within the sBitx app. You can edit the user_settings.ini to add the 9A/ prefix. We hope this solves your problem with the prefix. You are spot on on about update commands.
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Feel free to reach out to us if you have any other questions.
If you add it, you won't get ahead, because when someone answers your CQ like this, for example:
9A/W6ABD DE HA3HZ JN96 , then this text will be displayed in the reception like this: <...> DE HA3HZ JN96
If the QSO is successful, then the LOG will show <...> instead of the callsign. So it's not as simple as you answered here. I had a lot of trouble with this until I changed the monitor to an external hdmi and from then on I could use an external program (wsjtx or jtdx), for which this / does not cause any problems.
Yes you are right, changing settings by hand will seem to work, but it won’t send the packets correctly with such callsigns.
I think ft8_lib is incomplete in this way, and I had a shot at trying to fix it one time: ?. ?I didn’t succeed, and didn’t get back to it yet either. ?I had to operate with a prefix for the summer and fall until I got my Norwegian callsign, but it will come up again when traveling (and the zbitx will be handy for traveling). ?So there’s a starting point if someone else wants to help dig into it.
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Thanks Gordon. I have read that you turn the pot counter clockwise then bring it up slowly.
I have adjusted the fets on my Hardrock-50 amp when I put it together so I understand what
you are saying. I'll use a little 12v 2 amp meanwell supply. I'm guessing that the power is less
than 2 amps when making the adjustment.
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Thanks guys. I purchased this radio not working figuring that it was the fets that were bad.
I removed them and tested them and found that only one was bad. I am replacing both of
them today with new ones that came with the radio. That's the reason for all the questions.
Little by little I am learning. You guys are great and so helpful. Thank you all.
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Ah, what a great hobby this is!!? ?Even when we don't "start out" as electronics experts, we slowly BECOME ONE!!!? And that is part of why the Amateur Radio Service was Created (see 97.1)? ?So thanks for the photo, and I marked the one that is the bias pot.? BE CAREFUL? ?I don't know which way is "safe" -- youll need to read from someone else.? ?I? ?**always**? use a current limited supply (e.g. a real 12V wall wart or current limited supply) when adjusting these bias pots because if you max them out the WRONG WAY, you will get maximum current, instead of minimum when you apply power and hit "transmit".? ?So a little CARE is advised.? ?
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Remember, Ashhar does not design $10-thousand radios? ? ? He shows us how to make very simple stuff do AMAZING outcomes.? ? His designs are elegant.? ? ?You do have to read a bit (or ask questions, like you did, good job!)
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Gordon KX4Z
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Re: Operating FT8 from a different country
#sBITX_v3
On Mon, Dec 30, 2024 at 01:08 PM, Support HF Signal wrote:
This bug exists when you try to enter the callsign from within the sBitx app. You can edit the user_settings.ini to add the 9A/ prefix. We hope this solves your problem with the prefix. You are spot on on about update commands.
?
Feel free to reach out to us if you have any other questions.
If you add it, you won't get ahead, because when someone answers your CQ like this, for example:
9A/W6ABD DE HA3HZ JN96 , then this text will be displayed in the reception like this: <...> DE HA3HZ JN96
If the QSO is successful, then the LOG will show <...> instead of the callsign. So it's not as simple as you answered here. I had a lot of trouble with this until I changed the monitor to an external hdmi and from then on I could use an external program (wsjtx or jtdx), for which this / does not cause any problems.
--
Gyula HA3HZ
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On Mon, Dec 30, 2024, at 08:57 AM, bretnemeth wrote:
I think I understand. The other pot looks like it is in the receive circuit.
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The second pot is used in both the receiver and transmitter.? It sets the midpoint for the input to the mixer that is used to translate to the operating frequency.? The setting is non-critical.? Midpoint works well.
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73
Evan
AC9TU
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I think I understand. The other pot looks like it is in the receive circuit.
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The blue pot. left from the MOSFET’s on your picture.
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From: bretnemeth via groups.io
Sent: Monday, December 30, 2024 3:38 PM
Subject: Re: [BITX20] Set bias on sbitx
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Here is a photo of my board. One pot is not near the mosfets.
Does that mean I only adjust the one near the fets? I'm not a
big electronics guy but know just enough to get it done with
a little help.
?
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Looking at the schematic my guess I only adjust pabias1 near the fets.?
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Here is a photo of my board. One pot is not near the mosfets.
Does that mean I only adjust the one near the fets? I'm not a
big electronics guy but know just enough to get it done with
a little help.
?
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Joel Caulkins/N6ALT
Charles Guerin
HA3HZ
Jens/HB9JOI