Re: QDX - notes after day 1
Hello Peter
I use a 40m End Fed Half Wave - not had any RF issues previously using 100W.
A choke might help but not needed up to now.
I used a ferrite ring on the USB lead and a couple of clamp-on ferrites on the power lead.
But I have now just found a USB with built in ferrite cores at each end - a bit neater and seems to work just as well.
The QDX is a fun kit to build and very capable given the tiny size.
On 20m earlier today I heard stations from 5 continents in the same 15 second FT8 time slot - then picked up two VK stations 10 minutes later for a 6th.
It's nice to have the bands open :-)
I hope you get a QDX in the next batch !
Steve, G4GXL
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Order "in transit" at Grace-Hollogne for 3 weeks?
Hans,
I may need to be more patient but order #50620 has been in Grace-Hollogne since 21/10/2021 with the indication of "Shipment in Transit."? Since we are come up on 3 weeks "in transit" at the same location., I am wondering if there needs to be some investigation?? I understand only the shipper can find out information?
If there is no need to be concern, I will be more patient.
FYI, I have received my QDX from Sedalia and it is built and is on the air with 30+ Qs.
Thanks, Kent KC9LIF
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Re: A wish for later version of the QDX :-)
Nobody is forcing you to use an amplifier. And if you really want a weak?signal challenge, run your QDX from a 6 volt supply.
A T/R output also has other uses, such as switching between transmit and receive antennas or switching in a noise canceller. I think it would be a good addition.
On Tue, Nov 9, 2021 at 5:24 PM N3MNT < bob@...> wrote: Since we are voting, my vote is not to add a PTT out.? I enjoy the challenge of WEAK Signal operation.
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Re: A wish for later version of the QDX :-)
Since we are voting, my vote is not to add a PTT out.? I enjoy the challenge of WEAK Signal operation.
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Re: QDX - rig control error
Chris,
I was using a Raspberry Pi 4 connected to the QDX and running WSJT-X software.? The only way that I could get it to work was by selecting the serial port that showed up when I had plugged in the QDX and restarted WSJT-X.? The baud rate was set to 9600 and the polling for 10 seconds as per Han's suggestion.? The PTT control is set to CAT.
I actually started with a Windows10 laptop and had trouble with it.? I went to the RPi4 to solve the communication issues.
73
Evan
AC9TU
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Yes, and now it's off. So are the error messages. Thanks ever so
much, Mike.
On 11/9/2021 4:09 PM, mike/w1mt wrote:
toggle quoted message
Show quoted text
Is the decoder on?
mike/w1mt
On Tue, Nov 9, 2021 at 4:05 PM
Jim Campbell < jecspasc@...>
wrote:
I
built my QCX+ some time ago. When completed the power out was
approximately 3 watts. Recently I decided to get it up to 5
watts with a
13.6 volts DC supply. After taking 3 turns off L3 I achieved
my goal.
After putting my covers back on the QCX+ I discovered I had no
RF out.
Going back through the Menu settings I found a few things
amiss so I
corrected them. When I did a save configuration I got an "0 7
0 7" on
the bottom right of the screen. I cycled power and got a "T"
on the
bottom right of the screen and then another "T" with a space
between
them several seconds later. This continued till I powered the
QCX+ off.
I did a cursory pass through the documentation looking for
error codes
but was unable to find any. Can some kind soul tell me where
they might
be found?
Thanks es 73,
Jim - W4BQP since 1953
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Is the decoder on?
mike/w1mt
On Tue, Nov 9, 2021 at 4:05 PM Jim Campbell < jecspasc@...> wrote: I built my QCX+ some time ago. When completed the power out was
approximately 3 watts. Recently I decided to get it up to 5 watts with a
13.6 volts DC supply. After taking 3 turns off L3 I achieved my goal.
After putting my covers back on the QCX+ I discovered I had no RF out.
Going back through the Menu settings I found a few things amiss so I
corrected them. When I did a save configuration I got an "0 7 0 7" on
the bottom right of the screen. I cycled power and got a "T" on the
bottom right of the screen and then another "T" with a space between
them several seconds later. This continued till I powered the QCX+ off.
I did a cursory pass through the documentation looking for error codes
but was unable to find any. Can some kind soul tell me where they might
be found?
Thanks es 73,
Jim - W4BQP since 1953
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Jim,
The qcx firmware doesn't produce error codes apart from the 5351a error. Sounds like random CW characters to me..
Dean G7EOB.
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Re: Roots of Hans's supply chain issues
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.?
Bigger, less frequent orders are a long term solution anyway, even if they exacerbate current shortages. The logistics are much more efficient. You did what most should have been doing all along.
Or we could just blame local pollution standards. Imagine living in a world with such simplistic boogymen.
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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
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I built my QCX+ some time ago. When completed the power out was approximately 3 watts. Recently I decided to get it up to 5 watts with a 13.6 volts DC supply. After taking 3 turns off L3 I achieved my goal. After putting my covers back on the QCX+ I discovered I had no RF out. Going back through the Menu settings I found a few things amiss so I corrected them. When I did a save configuration I got an "0 7 0 7" on the bottom right of the screen. I cycled power and got a "T" on the bottom right of the screen and then another "T" with a space between them several seconds later. This continued till I powered the QCX+ off.
I did a cursory pass through the documentation looking for error codes but was unable to find any. Can some kind soul tell me where they might be found?
Thanks es 73,
Jim - W4BQP since 1953
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Re: A wish for later version of the QDX :-)
Curt - If a PTT is triggered as soon as the stop RX is recognised - it will give some delay before TX is started.?
Not necessary 200ms , but as good as possible.? Ignaff time to switch over some relays before the TX is started.?
zener diodes cal also be quite noisy just before trigger voltage reached - I do not think this will work.?
73 - Knut?
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Re: Thoughts on protecting BS170s in QDX
It is certainly worth some experimental effort. Somehow it needs to detect severe stress while not false alarming too often, as in FT modes quite annoying when rig decides not to transmit. I have many rigs with bs170 finals, zero failures but all these are Morse cw.?
Failure of si5351?? Perhaps you mean error in its quadrature.?
I don't know if this complexity makes sense versus reasonable derating of PA bias. One of my rigs did suggest some diodes to drop PA bias voltage, but I didn't do that. But for digital modes it may make sense to back down PA bias voltage.?
Curt
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Just a thank you to Hans. I bought another of his excellent QCX+? and a 50w amp. Part of the process of transferring my bank account into his. They arrived very quickly, despite me not once asking on here as to where they were. His postal system is working very well and after an initial delay, it takes a day or two for packages to be picked up from his location, they arrived in the UK very quickly.
I can only wonder at the chaos that must have ensued recently with having to ship out some 500 new product kits. I would like to say a big thank you to the people who work with Hans. The kits are well packed and it can't be easy ensuring each kit has all the necessary components in it.
Hans and his employees are all doing a great job and have improved the QRP side of ham radio enormously. Some days I reckon they bump into themselves coming back the other way?????? >:-)
Reg??????????????????? G4NFR
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Re: QDX - rig control error
Ken, Bob,
As a follow-on to my earlier note, I can confirm 'Mode' was set to 'None'.? I read somewhere that changing 'Handshaking' from 'default' to 'none' had been beneficial for the writer, but that made no difference here.
I changed port settings - 'USB' was available but that resulted in a different error:? invalid configuration.? So I tried typing dev/ttyUSB0 in full, which produced yet another error variant:? IOerror
My next step is to try the QDX with WSJT-X loaded onto a W10 laptop, which I don't normally have available, in the hope that it will at least allow me to confirm that I have a fully working QDX.? No reason at the moment to think otherwise.
Thanks again for your input and maybe someone else will be able to chip in with observations.
Chris? G4CWS?
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Re: OT: Congratulation JackW8TEE
Thanks Jeff. I think the first column will be out next month.
Jack, W8TEE
On Tuesday, November 9, 2021, 12:52:14 PM EST, Jeff | VA2SS via groups.io <jeff@...> wrote:
Hi,
I would like to congratulate Jack W8TEE for his nomination as? Microcontrollers Editor for CQ Magazine.
Like many excellent contributors we already have in this group, we are grateful to all who like to share their knowledge.
Best regards and 73.
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Jeff | VA2SS
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My dual band QCX is ready and functioning :)
I just like to share hat i have made a dualband 2m/10m QCX. No rocket science but a small internal transverter fits perfect in the case. I love those QCX¡¯es!
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Re: QDX firmware minor release 1_01b
#qdx
Just adding some unscientific anecdotal evidence as I too experienced catastrophic failure of a BS170 while transmitting on 20m.? Same situation, lots of QSOs on 40m, switched over to 20m and heard a pop midway through the first transmission.??
Now I may also have been doing some other foolish things like trying to power it with a DC-DC buck converter (which to be fair didn't seem to be a problem on 40m), and I have not tuned my 20m dipole lately so it could well be there was lots of SWR.? I've since built a linear regulator and I'll check the antenna, but I'm still wary of trying 20m again.
Fortunately I was able to replace all 4 transistors and I seem to be back in business at full power.
Dennis
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Re: Thoughts on protecting BS170s in QDX
On Tue, Nov 9, 2021, at 11:44 AM, Steven Dick wrote:
The push-pull output stage can theoretically be damaged if the out of phase drives to the BS170 pairs become faulty for various reasons
Steven, I do not understand the above statement.? As I look at the QDX PA circuit it seems that both of the output pairs could be on at the same time and have the same current through each pair as if the driver signal were out of phase as it should be.? For that period of time, the total current would be twice normal, but there is not a rail to rail issue as is the case for a totem type of output.? Leaving that current on for too long would cause damage to one or both sides of the push-pull output.? That could be the failure you are describing.? It could be caused by software when detecting the loss of the USB sound card connection and the processor does not shut down the TX signal soon enough to avoid a problem.? Or maybe leaves the Si5351 in a bad state like you are describing.? The point is that the phase relationship would be less of an issue as compared to letting a gate be turned on too long.? This might be supported by the fact that one side of the output seems to be damaged at a time.? All just speculation on my part. As I see it, the high voltage on the BS170s can be caused by feedback from the antenna.? The instantaneous voltage or current could feedback through the transformer as a voltage spike across the drain/source connections of the MOSFET. I do like the idea of current sensing and turning off the drive to protect the output devices regardless of the failure cause.? It does add cost and real estate to an already cramped board. FWIW 73 Evan AC9TU
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Hello,
After a burnt of the old LM1117 regulator, I changed to a 78M05 and lot of other components (uP, diodes, Si 5351, 74ACT00, LCD,? and the 3 BS170)
I am blocked on the FST3253. When I have a signal on Z and W (180¡ã phase shifted) of 7.02MHZ .. I have nothing at the output on X0-X3 , Y0-Y3. I changed the FST3253 and remove the resistances R5,R6,R8 and R9 .... Nothing ....
On the input, I have a DC component of 3.6V plus my RF signal .... at the output a DC component of 2V and no AC signal at 700Hz ...
I firstly don't understand why the DC component at the input isn't 2.5V .... and why these strange values at the output. I changed twice the FST, the 5V DC is ok, and the clocks signals from Si 5351 also .... It seems like the MUX is not working ???? Any idea to test it ??
Best 73,
Nico
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Retired Doc
Shirley Dulcey KE1L
N3MNT
Knut Steinar Fremme OE4KSF
jjpurdum
Dick PA3CW