Thanks Evan
?? I put the QDX in its case. The USB cable has ferrites on both ends. I also coiled the excess length and tied it together.
For these tests I'm transmitting into a dummy load and using 9 volts power, so I only have 2.4 watts out (T1 is 3:2).
? I still saw the same behavior. Flashing led with power output on 40 and flashing led but no RF out on 20, 30 and 80 with no current draw on those bands above receive.
? My low band antenna is a lazy (drunken?) sorta vertical 57' long that runs from the remote tuner at the corner of my garage to the top of a nearby tree. There is a buried radial field of wires out to the edges of the yard. Since I use a remote tuner there is close to 1:1 on the coax leading in, but I also have several turns of coax through 6 FT240-43 torroids. There's also a box with relays that switch in a loading coil for 160 m so the antenna can be tuned easily and it disconnects and grounds the antenna when power is off.
? Good luck with your low power problem.
--
? 73
??? KD8CGH
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Re: Roots of Hans's supply chain issues
Love that movie!
Roy WA0YMH
Well, it?reminds me of my favourite "Snatch" movie line... "Never underestimate the predictability of stupidity".?
73 Hans G0UPL
On Mon, Nov 8, 2021 at 6:17 PM Mike Perry, WA4MP < editor@...> wrote:
> I don't think there's any great conspiracy or powerful forces directing it - but this is just the way the world system has been evolving. Thousands of individual decisions that make sense on a micro level, add up to make big consequences.
Quite right. I try not to ascribe to conspiracy anything that could be the result of stupidity. I once saw a cartoon that was all too apt. ¡°Be proud of your stupidity,¡± it said. ¡°It¡¯s what separates us from the animals."
For years I¡¯ve been warning Apple on Mac news sites not to do so much single sourcing, particularly in China. Always have several sources even if some cost more, I stressed. Recently, Apple announced that it would lose $8 billion dollars due to supply chain issues. I feel like I should bill them for business advice not taken.
And those California ports are jammed in part because the state¡¯s politicians stupidly passed a law that means that few trucks older than three years meet the pollution standards. Long-distance truckers, with more business than they can handle anyway, simply avoid trips into and out of the state. Politicians make one decision, thousands of truckers respond with another. No conspiracy. Just stupidity followed by a predictable and reasonable response. Truckers know trucking. Politicians do not.
¡ªMike Perry, WA4MP
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Re: Roots of Hans's supply chain issues
There's something like the 'law of unintended consequences'. You do one thing that makes sense and all sorts of things happen that you didn't expect.?
--
73, Dan? NM3A
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Brian, quick first question is what are you using for a power source? ¡°Wall wart¡± supplies are notorious for not always being well filtered and can cause such issues.?
Ron
On Mon, Nov 8, 2021 at 09:55 Brian Pease < bpease2@...> wrote: I just completed a new Progrock using the recommended power/regulator setup.? The voltages are correct, correct parts, no shorts on the boards, controller installed in the socket correctly. . It powered up with 4 flashes and output the default 10MHz on clk 0.?
The first problem is that the 10MHz signal is amplitude modulated with an audio frequency square wave of ~377Hz.? This is large, at least 50% modulation.
The second problem is that I cannot program a new frequency. Push-button presses of any short duration cause the LED to light only for the duration of the press. Repeated presses (5-10 or more) eventually result in the 4 flashes but programming is not possible.
Clock 1 has a rail-rail output of ~210kHz.
This is version 5. The controller is labeled pr1.02.
???????
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I just completed a new Progrock using the recommended power/regulator setup.? The voltages are correct, correct parts, no shorts on the boards, controller installed in the socket correctly. . It powered up with 4 flashes and output the default 10MHz on clk 0.?
The first problem is that the 10MHz signal is amplitude modulated with an audio frequency square wave of ~377Hz.? This is large, at least 50% modulation.
The second problem is that I cannot program a new frequency. Push-button presses of any short duration cause the LED to light only for the duration of the press. Repeated presses (5-10 or more) eventually result in the 4 flashes but programming is not possible.
Clock 1 has a rail-rail output of ~210kHz.
This is version 5. The controller is labeled pr1.02.
???????
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Re: On the TX signal, 5V tolerant I/Os and Pull-up resistors
Hi Fred?
I don't agree... When the pin is an output, the processor sets it at either 0V or 3.3V. Provided its current handling capability isn't abused, it doesn't matter what voltage it is "pulled up" to. It could be 1,000V provided the resistor was big enough, nobody would care.?
A 5V tolerant IO pin can withstand being connected to a low impedance 5V source. There are several clamping diodes in series so they don't draw huge current if the IO pin is connected to +5V.?
Those five pull up resistors are, categorically, totally unnecessary and totally harmless. Or I'll eat my hat.?
By all means remove them if it makes you feel better. I removed them in Rev 2. But not because they worried me at all. Just because less components is always better, even if only slightly so. More ground plane, less cost. Etc.?
I'm operating my QDX here every day without issues, on 40m and 20m. I've switched to 80m and 30m too but for receive only because my antenna isn't designed for 30m or 80m.
73 Hans G0UPL http://qrp-labs.com
-------- Original message -------- From: Fred Spinner <fred.spinner@...> Date: Mon, Nov 8, 2021, 7:27 PM To: [email protected]Subject: Re: [QRPLabs] On the TX signal, 5V tolerant I/Os and Pull-up resistors Interesting.? I am reading that you should not have those pull-ups to 5V there at all if the pin is used as an output.? The inputs have clamping diodes to clamp the 5v input to 3.3v.? If anything having a 5v pull up will burn off current for no gain in the STM32 through one of those clamping diodes.??
It probably makes sense to remove those pull-ups if for anything else lower current draw.? I would normally agree that the risk of damage doing this is low due to the 10k value of pull-up, but there is at least some circumstantial evidence that you might be seeing TX and LPF switching problems now from what is being reported here.? ?Could it be this?? I honestly think it could be.?
So yeah, I will probably pull them on mine.? Again, couldn't hurt, might help.?
Fred W0FMS Hi Fred
The 5V tolerant IO and the pull-up resistors to?+5V are all a red herring.?
According to the BS170 datasheet, the device has a gate threshold voltage of typically 2.1V but it could be as low as 0.8V or as high as 3.0V. I was nervous about?3.3V logic perhaps not driving it at sufficient voltage to be properly "ON". In other words not much safety margin between the 3.3V operating voltage of the microcontroller - bearing in mind the output will?not quite be rail-to-rail - and the worst case gate threshold?of the MOSFET.
My plan therefore was to use 10K pull-up resistors to?+5V. Then when I wanted the MOSFETs "On", I would set the I/O pin to be an input; and the 10K resistor would pull the MOSFET gate to?+5V. When I wanted the MOSFET to be "Off", I would set the I/O pin to be an output and set its level low. This is why you see these 10K pull-up resistors at the gates of the Tx/Rx switch Q6, and the three band select switches, and Q2 (on the TX signal).?
HOWEVER... I was mistaken. Because the transistor I used is BSS123 and according to its datasheet, its gate threshold voltage is minimum 0.8V, typical 1.7V, and maximum 2V. Therefore there is a lot more head room than I had expected with a BS170. So in the end, I did NOT keep to my original plan. I simply have the TX, RX and Band control signals all active all the time as Outputs, and set to high (3.3V) or low (0V) by the firmware. In either case (high or low), the pull-up to?+5V is of no consequence. It is an 0.5mA annoyance when the pin is at 0V, and a 0.17mA annoyance when the pin is at 3.3V. Nothing else.?
The microcontroller is not operated out of its spec. There is no possibility of damage. The pull-up resistors are ignored by the current firmware. Irrelevant. Unnecessary.?
As a matter of fact, in Rev 2 of the PCB, I simply deleted those pull-up resistors. I am talking about R5, R10, R11, R12 and R14. They are not required.?
Fred if you want to remove these resistors please go ahead. It makes no difference...?
73 hans G0UPL
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Re: On the TX signal, 5V tolerant I/Os and Pull-up resistors
Interesting.? I am reading that you should not have those pull-ups to 5V there at all if the pin is used as an output.? The inputs have clamping diodes to clamp the 5v input to 3.3v.? If anything having a 5v pull up will burn off current for no gain in the STM32 through one of those clamping diodes.??
It probably makes sense to remove those pull-ups if for anything else lower current draw.? I would normally agree that the risk of damage doing this is low due to the 10k value of pull-up, but there is at least some circumstantial evidence that you might be seeing TX and LPF switching problems now from what is being reported here.? ?Could it be this?? I honestly think it could be.?
So yeah, I will probably pull them on mine.? Again, couldn't hurt, might help.?
Fred W0FMS
Hi Fred
The 5V tolerant IO and the pull-up resistors to?+5V are all a red herring.?
According to the BS170 datasheet, the device has a gate threshold voltage of typically 2.1V but it could be as low as 0.8V or as high as 3.0V. I was nervous about?3.3V logic perhaps not driving it at sufficient voltage to be properly "ON". In other words not much safety margin between the 3.3V operating voltage of the microcontroller - bearing in mind the output will?not quite be rail-to-rail - and the worst case gate threshold?of the MOSFET.
My plan therefore was to use 10K pull-up resistors to?+5V. Then when I wanted the MOSFETs "On", I would set the I/O pin to be an input; and the 10K resistor would pull the MOSFET gate to?+5V. When I wanted the MOSFET to be "Off", I would set the I/O pin to be an output and set its level low. This is why you see these 10K pull-up resistors at the gates of the Tx/Rx switch Q6, and the three band select switches, and Q2 (on the TX signal).?
HOWEVER... I was mistaken. Because the transistor I used is BSS123 and according to its datasheet, its gate threshold voltage is minimum 0.8V, typical 1.7V, and maximum 2V. Therefore there is a lot more head room than I had expected with a BS170. So in the end, I did NOT keep to my original plan. I simply have the TX, RX and Band control signals all active all the time as Outputs, and set to high (3.3V) or low (0V) by the firmware. In either case (high or low), the pull-up to?+5V is of no consequence. It is an 0.5mA annoyance when the pin is at 0V, and a 0.17mA annoyance when the pin is at 3.3V. Nothing else.?
The microcontroller is not operated out of its spec. There is no possibility of damage. The pull-up resistors are ignored by the current firmware. Irrelevant. Unnecessary.?
As a matter of fact, in Rev 2 of the PCB, I simply deleted those pull-up resistors. I am talking about R5, R10, R11, R12 and R14. They are not required.?
Fred if you want to remove these resistors please go ahead. It makes no difference...?
73 hans G0UPL
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Re: QDX has no power out
#qdx
Hi Evan.
In my previous work life, I made use of the fact that most CPUs never go totally to 0.0 volts, they usually will be above zero and well under 0.5 volts. When I was trouble shooting a CPU or logic problem, if I measured true zero volts, I looked for a short. If I measured anything between zero and 0.5 volts, I looked for a logic problem. And if I still couldn't find the problem, I'd finally check the voltage at both ends of the PCB trace just in case it was open. It didn't happen often, but once in a while the pin would look soldered but would be floating above the matching pad insulated by a bit of flux. I can't begin to guess how many times there was a micro-thin short between pins or traces that I couldn't see even under the microscope, but washing away the flux residue and cutting between the traces would solve the problem. But I'd also say you are right to be careful before getting too frisky with the Exacto knife if you don't have good magnification to work with. :-) When I was doing repairs, I could always tell when the previous tech was using a 3x bench light instead of his 10x microscope while doing his soldering. The better the seeing, the better the work on small SMD parts. Good luck with the repairs.
Doug.
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For those interested:
https://ae5x.blogspot.com/2021/11/spectrum-analysis-qdx-on-60m.html
--
John AE5X
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Re: QDX , Lost my TX power
Hi Matt,
Have you measured your RF voltage at the output of T1 yet with your probe? The RF should be about the same as at the BS170¡¯s, this is the junction of C32, C34, T1.
C32 feeds the voltage doubler to make sure the 1N4007 pin diodes switch so there should be RF voltage on both sides of C32. With your volt meter you should measure DC voltage at the D7,8 junction higher than your B+ on TX (correct me if I¡¯m wrong Hans). C34 is the path of TX output to the selected LPF. If your RF probe is measuring about the same level on both sides of C34 then it comes down to the LPF selection and associated switching components. This brings in all the 47uh chokes that you installed if there is B+ across all of the chokes feeding the LPFs then there maybe a problem with the BS170¡¯s not being switched on to select the filters.
Skip Davis, NC9O
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Re: Elecraft KXUSB with QCX Mini
An additional note:
RS232 logic "1" is a negative voltage, logic "0" is positive.?
TTL logic "1" is a positive voltage and logic "0" is 0 (or a very
low positive voltage)---NORMALLY
Milt W8NUE
On 11/7/2021 9:03 PM, richlim11 via
groups.io wrote:
toggle quoted message
Show quoted text
Milt, you are correct I did search and Elecraft uses RS232 levels
and the QCX mini needs TTL levels. Thanks.
John you may want to check your cable, you may damage your QCX
mini if it is indeed at RS232 levels.
Rich KQ9L
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Re: Roots of Hans's supply chain issues
I think it's the "just-in-time" inventory thought process that puzzles me as an economist the most. I can understand skimping on inventory during the Carter years when the prime interest rate was 21%, but when real interest rates are near 0 and there's a known risk of getting caught with your pants down, I don't understand why "the Big Three" and others (e.g., Elecraft) didn't stockpile key components like Hans did. I find this even more puzzling with components where second sources seem slim.
Yeah, I realize it's easy to use 20-20 hindsight, but still...
Jack, W8TEE
On Monday, November 8, 2021, 09:30:38 AM EST, Mike Perry, WA4MP <editor@...> wrote:
The captain of a large cargo vessel has a great video explaining the various roots of the issues Hans has with getting the parts he needs. This comment about the high-tech industry is particularly relevant.
> 4:26 "... delicately balanced supply chain ..."? What you should have said is "a perilously stretched supply chain that had no contingency plans." I have worked in the high-tech supply chain discipline for almost 15 years, and top management has refused to listen to warnings or do any risk planning for longer than I've been in it. Everything has been leaned out to the max, to maximize profits and bonuses. Now the economy and consumers are paying the price, while the execs who put us here are sitting on piles of cash.
>
When a system of trade is already being pushed to its limits by a desire to maximize profits with a just-in-time inventory, it has no reserves to call on when a crisis develops. We¡¯ve had several major ones in the last couple of years. The troubles then feed on one another. Those 70+ ships sitting at anchor off LA and San Diego aren¡¯t available to ship other cargos between other ports in other countries.
Interestingly, I¡¯ve not noticed any increased delays in the orders I¡¯ve made from China to ready for the arrival of that QCX mini. The last of them, an iambic key, should arrive today. They take several weeks to arrive just like before but not more weeks. Of course, what I was ordering was small and seems to have gone space available on cargo aircraft. The package may sit a week or so waiting for a flight out, but it¡¯s not on a ship waiting at anchor for weeks like larger cargos.
¡ªMike Perry, WA4MP
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Re: Roots of Hans's supply chain issues
On Mon, Nov 8, 2021 at 02:29 PM, Mike Perry, WA4MP wrote:
The captain of a large cargo vessel has a great video explaining the various roots of the issues Hans has with getting the parts he needs.
He is actually the chief engineer. I was an engineering officer in the merchant navy and we were all more important than the captain and other deck officers. They were just the engineers "look outs" who tried not to bump into anything while we conveyed them from port to port. Fortunately I left just as container ships were starting to appear. We used to spend a week or ten days at a time in port while loading and unloading. That meant plenty of time to go ashore. Next time you are on a ship, maybe a cruise ship, endear yourself to the captain and other deck officers by stating that you know they are actually just the engineers lookouts. Seriously... ?? the chief or second engineer on a merchant ship could leave and get nearly any (highly paid ) job ashore, such is there qualifications. Reg?????????????? G4NFR ? ?
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I get this constant tone as well. Will hope for a fix even though the mini is still usable.
73 de Arnie W8DU
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Re: Roots of Hans's supply chain issues
Reminds me of the joke about the gentleman who invested all his money in toilet paper and revolving doors. He was wiped out before he could turn around................
Lee KX4TT
On Monday, 8 November 2021, 10:41:38 am GMT-5, Mike - N5AQM <n5aqmdb@...> wrote:
A friend of mine is a Technical Marketing Engineer for Microchip for one of their uController lines. He has told me numerous times that every month they could sell twice what they produce and they are running flat out full capacity. He thinks that his customers are suffering from the toilet paper syndrome....
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Re: Roots of Hans's supply chain issues
A friend of mine is a Technical Marketing Engineer for Microchip for one of their uController lines. He has told me numerous times that every month they could sell twice what they produce and they are running flat out full capacity. He thinks that his customers are suffering from the toilet paper syndrome....
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Re: Roots of Hans's supply chain issues
Well, it?reminds me of my favourite "Snatch" movie line... "Never underestimate the predictability of stupidity".?
73 Hans G0UPL
On Mon, Nov 8, 2021 at 6:17 PM Mike Perry, WA4MP < editor@...> wrote:
> I don't think there's any great conspiracy or powerful forces directing it - but this is just the way the world system has been evolving. Thousands of individual decisions that make sense on a micro level, add up to make big consequences.
Quite right. I try not to ascribe to conspiracy anything that could be the result of stupidity. I once saw a cartoon that was all too apt. ¡°Be proud of your stupidity,¡± it said. ¡°It¡¯s what separates us from the animals."
For years I¡¯ve been warning Apple on Mac news sites not to do so much single sourcing, particularly in China. Always have several sources even if some cost more, I stressed. Recently, Apple announced that it would lose $8 billion dollars due to supply chain issues. I feel like I should bill them for business advice not taken.
And those California ports are jammed in part because the state¡¯s politicians stupidly passed a law that means that few trucks older than three years meet the pollution standards. Long-distance truckers, with more business than they can handle anyway, simply avoid trips into and out of the state. Politicians make one decision, thousands of truckers respond with another. No conspiracy. Just stupidity followed by a predictable and reasonable response. Truckers know trucking. Politicians do not.
¡ªMike Perry, WA4MP
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Re: Roots of Hans's supply chain issues
I don't think there's any great conspiracy or powerful forces directing it - but this is just the way the world system has been evolving. Thousands of individual decisions that make sense on a micro level, add up to make big consequences. Quite right. I try not to ascribe to conspiracy anything that could be the result of stupidity. I once saw a cartoon that was all too apt. ¡°Be proud of your stupidity,¡± it said. ¡°It¡¯s what separates us from the animals." For years I¡¯ve been warning Apple on Mac news sites not to do so much single sourcing, particularly in China. Always have several sources even if some cost more, I stressed. Recently, Apple announced that it would lose $8 billion dollars due to supply chain issues. I feel like I should bill them for business advice not taken. And those California ports are jammed in part because the state¡¯s politicians stupidly passed a law that means that few trucks older than three years meet the pollution standards. Long-distance truckers, with more business than they can handle anyway, simply avoid trips into and out of the state. Politicians make one decision, thousands of truckers respond with another. No conspiracy. Just stupidity followed by a predictable and reasonable response. Truckers know trucking. Politicians do not. ¡ªMike Perry, WA4MP
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Re: Deal on QRP-Labs power plugs
Those who want to avoid playing Amazon roulette might want to try this West Virginia-based vendor. They sell a lot of these plugs to those who install alarm and CCTV systems and don¡¯t want to lose those customers. I imagine they source those plugs in China, but take care to keep the quality up. The problem with Amazon is that it is so blasted big, it doesn¡¯t need to pay much attention to quality. At best, it offers a return policy, but for small orders, a return isn¡¯t worth the hassle.
I¡¯ve also found that Jex Electronics ships the day I order or the next and, being first-class mail, it arrives quickly. Another problem with Amazon roulette is that you don¡¯t know how quickly an order will ship. I¡¯ve had shipping take as long as a week, particularly on small orders with multiple items.
I also worked one summer in the warehouse of an electronics wholesaler. It¡¯s miserable, dull work. I wouldn¡¯t work for Amazon if I could find any other place to work.
¡ªMike Perry, WA4MP
toggle quoted message
Show quoted text
On Nov 8, 2021, at 8:43 am, Mario Vano <mvano@...> wrote:
Yuck, mine are definitely copper of the right size, but as I said: Amazon uses something called "inventory commingling" to ship items from several different vendors apparently at random in response to an order. I've been pretty lucky (but not always). I just assume it's a cost of dealing with them and have learned to move on...
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Bob Benedict, KD8CGH
Ronald Taylor
Fred Spinner
Skip Davis
jjpurdum
Lee
Mike Perry, WA4MP