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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


Re: Elecraft KXUSB with QCX Mini

 

¿ªÔÆÌåÓý

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:

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


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





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

? ?


Re: QCX mini constant tone #qcxmini

 

I get this constant tone as well. Will hope for a fix even though the mini is still usable.
73 de Arnie W8DU


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....


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....


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










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


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

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...


Re: Roots of Hans's supply chain issues

 

Hi Mike

It is not just profit-driven. We have seen decades of a relentless drive to make everything cheaper. Profit = Revenue - costs. The consumer pushes revenue down and the manufacturer has to push costs down or get squeezed out. The delicate situation arises. I think it may be a bit harsh to say that consumers (ordinary folk like you and me) demand lower and lower prices. But the global system is set up in such a way that this result naturally arises.?

One can theorize about the global semiconductor shortage. Factory closures, workforce shortages, logistics problems, Covid19-driven lapse in demand then back with a vengeance 6 months later, work-from-home demand for tech goods etc etc. But in the end we can see similar issues in other areas too. Look at the recurring toilet roll crises (among other common household items). Empty supermarket shelves. Though there was never any shortage of toilet rolls (no supply issues), nor was there a sudden extra demand caused by any particular need for the cleaning of the human posterior to be required much more frequently. Just panic, human emotion. Scaled up, that's also a factor in the chip shortage.?

I myself am guilty of it too. When I heard of the shortages I immediately bought 4,000 Si5351A from Digikey and Arrow which cleaned out their entire stock. Normally I'd only buy them by the reel (2,500), one reel at a time, when I needed them. Not 4,000 in one go even when I still had a partial reel left. At the same time I bought 2,500 ATMega328, these were also unobtainable for a few months. It was a temporary investment for me as long as I believe I will use the chips up... and it did mean I could continue QCX-mini and QCX+ production without interruption, throughout the last 2 years. From my point of view as a manufacturer, it made sense for business continuity. But if every manufacturer got scared and did the same thing, which they did, you see what happens.?

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.?

73 Hans G0UPL

On Mon, Nov 8, 2021 at 5:31 PM 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





Re: QDX: any estimate when the last of the first batch units will all be shipped out?

 

Thanks, Hans. ?I found the shipping confirmation email. ?Yahoo mail does some very odd things.

73, Ben ?K0IKR


Re: Deal on QRP-Labs power plugs

 

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...

m


Re: QDX Surface Mount inductors

 

Hans,

This is a totally acceptable solution for me.? Glad that you cleared up my understanding.? Now to wit for the availability of the v2 kits.

73
Evan
AC9TU


Roots of Hans's supply chain issues

 

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


Re: QDX Surface Mount inductors

 

Hello Evan
?
As an interim solution to get past the high demand stress I would agree.? You do need to note that this will add a complexity that some intermediate level builders with have issues in the installation.? I consider myself a somewhat advanced builder and it was a challenge for me.? The board is very small and cramped, so this type of modification is a challenge.?

I apologize if I was unclear.?

Rev 2 PCB uses through-hole axial molded 47uH inductors, as were supplied with the Rev 1 boards. However on the Rev 2 PCB, there are through-hole pads on the board for these, and they take the place of the SMD parts which are deleted from the design. In Rev 2, there is therefore no need to remove SMD components and replace them with tacked-on through-hole inductors. Installation?of the four through-hole inductors is as easy as any other?through-hole components.?

73 Hans G0UPL


Re: QDX , Lost my TX power

 

I think you need to check the output of??IC5 - driver for the BS170.

When my got busted - I did also measure about 27dBm? (should have been about 37dBm) out of the transistors after changing , but only 0.13W out.

Looking at the output using instruments - I find that the signals? do not look nice at all - and the filters will take out the spurious and then nothing on the antenna connector.

Only one side of the Push-Pull was working as the output from IC5 was also broken

73 Knut

?


Re: QDX , Lost my TX power

 

I finished mine yesterday an I had about 25 QSOs on 40 and 30 m (40m with Dipole, 30m with lw). Than I changed to 20m (Magnetic Loop..... I tuned the Loop before with my TS940 got get the resonance frequenzy, good SWR) . Also 5 Watts with about 13V. Than.after 10 times calling CQ.......Smoke. I burned two BS170. I substituted all 4. I can receive , and I hear the Transmission with my TS940, but no Power at the output behind the low passes.
I made a measurement directly at the Transistors. with the RF probe (thanks to George Dobbs :)? ). 40V, about 4Watts. Seams to bee, that the new Transistors are working. But no Power to the Antenna Socket. Something destroyed within the Power line... :( . Any Idea ? I never made anything with SMD. First time for me was the replacement of the 47?H. But it worked well.
Maybe C34 damaged ?And as a result, no power arrives the low passes ?
73 de Matt , DL1SER

?


Re: QDX, one out of four

 

Hello Bob,

Congratulations on your 40 meters success.? This does indicate that the build is most likely OK.? Hans Summers has written a post that describes what some of the causes might be for low or no power output.
/g/QRPLabs/message/74132

Based on your symptoms, I would suspect that the USB audio connection is being interfered with.? Look at the?"TX" signal and "RX" signal?section of the post.??

Note that there are two conditions to get power out as stated in the post.? The one is being met: The CAT command to set the rig in transmit mode is being received.? I suspect the other one, a valid tone from the PC, is not.? The most likely cause of this is that there is RF blocking the USB audio when it first keys up and quickly knocks out the USB connection for long enough to drop out the TX signal.? The CAt command is still active, so it appears to be in transmit mode.? This is supported by the current draw NOT going high as it does on 40 meters.? One possible way to verify might be to try transmitting into a shielded dummy load and see if you get power on all bands.

Hans indicated steps to take to address this issue.? My suggestion is snap-on ferrites, as that worked for me with my other RF-sensitive rig to computer connection.? In trying to find out the cause of my low power issue I have blown the BS170s and need to replace them before I can verify that the ferrites work for me with the QDX.

Out of curiosity, what are you using for an antenna?

Good luck and happy hunting (for the bug).
73
Evan
AC9TU


QDX firmware minor release 1_01b #qdx

 

Hi all

A potential new failure mode was discovered, wherein if you happened to accidentally enter a grossly incorrect calibration reference frequency in the configuration screen, you could burn two of the BS170s. For example if you meant to enter 25,000,002 but accidentally wrote 2,500,002 then the Si5351A configuration could not succeed, resulting in a DC output on the Si5351A pins, putting one pair of BS170s 100% on (high current) and the other pair 100% off (no current).?

To resolve this 1_01b now does a check to make sure that the entered frequency is 25MHz?+/- 1kHz. Outside this range, it would be ignored.?

This is a minor non-essential upgrade, just another protection against a possible?failure mode.?

73 Hans G0UPL