Re: Blue screen of death U3s
I had a similar (maybe lightning) problem with a QCX+5W.? ?In that case I replaced the Si 5351 A-B-G? several times as well as the QCX demodulator chip (you don't have)? without getting it going.? ?
I wondered if the first 2 5351A B GT 's? were miss sold pre-programmed ones so tried one from another source.? I used my spare CPU chip too the third time of praying and it all worked again.? I've not swapped the CPU back yet but suppose I ought to get round to it.??
?
The chip that definitely did work was?
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Re: QDX 80M Band Sweep Question
On 24/08/2023 17:41, Wayne Greene wrote: I ran RF filter sweeps on all of the bands to see if maybe something was wrong with my LPFs (assuming that's what this tests). Wayne. It tests the BPFs. Unless your LPFs are very bad they will make no noticeable difference. 73 Alan G4ZFQ
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Looking at the photo on page 24 of QMX manual h, I think maybe diode D508 may be pictured in the wrong orientation.
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Either Meinberg or Dimension 4 will work well for Windows systems, and I highly recommend the use of either one instead of the built-in Windows time sync, which frankly sucks. For Linux folks, Meinberg will work although you may need to compile before installation. I normally work with Ubuntu, which has pretty decent NTP facilities available?as timedatectl / timesyncd.?
If you have a dual-boot system like mine (Windows 10 / Ubuntu with plans to add Mint as a third OS), set Windows and Linux both to UTC as the primary time; that will save you some hassles when moving from OS to OS.
Lee KX4TT
On Thursday, August 24, 2023 at 01:42:51 PM EDT, Chuck Moore via groups.io <wd4hxg@...> wrote:
Dan
I have the coffee can version of T-Mobile Home Internet Cellular Modem and
run Meinberg NTP on my machines when using T-Mobile. Thus far, NTP has
been golden.? Using Windows NTP services however is another story. Sometimes
it works, sometimes it doesn't. So I simply disable Windows NTP and use Meinberg
full time.?
Regards
Chuck WD4HXG
On Aug 24, 2023, at 10:55 AM, Daniel Walter via groups.io <nm3a@...> wrote:
One obscure issue with time sync:
I have a cellular internet modem (T-Mobile) and it will not allow most of these time syncs, such as Dimension4, or many others, to work. It will also not allow ftp sites to work.
My work around for this is to use a Personal Hotspot from my cell phone. Even though it uses the same cell network and the same tower, this works, while the cellular internet modem does not- go figure.?
But built in time syncs in Windows and Mac OS do work fine, tho.?
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73, Dan? NM3A
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Re: QDX 80M Band Sweep Question
My main ham system is a Pi-400. Works great and no funny issues like Windows.
I don't know if you've run fldigi etc. on Linux before, but this HowTo is a very helpful guide to the building and usage of fldigi and the other flxxx apps on Linux (including the Pi), MacOS and Windows.
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Thanks. I'm sure there is one, as well. I'd say this is causing me to pull my hair out, but I'm already bald...HIHI. I may try running this on a pi to see if I get better results.
Wayne
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Re: QDX 80M Band Sweep Question
Thanks. I'm sure there is one, as well. I'd say this is causing me to pull my hair out, but I'm already bald...HIHI. I may try running this on a pi to see if I get better results.
Wayne
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Re: QDX 80M Band Sweep Question
I've been following the thread on your audio issue. Very strange as obviously the sound card is working and Windows sees it. I'm not a Windows guy, just have a test setup with Win10. Anyway I'm waiting to see what the solution is. I'm sure there is one.
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Awesome. Thanks for the response. I ran RF filter sweeps on all of the bands to see if maybe something was wrong with my LPFs (assuming that's what this tests). All part of my still troubleshooting my audio problem.
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Dan
I have the coffee can version of T-Mobile Home Internet Cellular Modem and
run Meinberg NTP on my machines when using T-Mobile. Thus far, NTP has
been golden.? Using Windows NTP services however is another story. Sometimes
it works, sometimes it doesn't. So I simply disable Windows NTP and use Meinberg
full time.?
Regards
Chuck WD4HXG
On Aug 24, 2023, at 10:55 AM, Daniel Walter via groups.io <nm3a@...> wrote:
One obscure issue with time sync:
I have a cellular internet modem (T-Mobile) and it will not allow most of these time syncs, such as Dimension4, or many others, to work. It will also not allow ftp sites to work.
My work around for this is to use a Personal Hotspot from my cell phone. Even though it uses the same cell network and the same tower, this works, while the cellular internet modem does not- go figure.?
But built in time syncs in Windows and Mac OS do work fine, tho.?
--
73, Dan? NM3A
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Re: QDX 80M Band Sweep Question
Awesome. Thanks for the response. I ran RF filter sweeps on all of the bands to see if maybe something was wrong with my LPFs (assuming that's what this tests). All part of my still troubleshooting my audio problem.
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Re: QDX 80M Band Sweep Question
Yes, it's actually quite good for 80M. Better than mine.
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This is the band sweep of 80M on my QDX. I'm wondering if this is normal:
<dummyfile.0.part>
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Re: QMX AGC... any progress?
Ronan,
I was the guy that posted the limiter circuit back when. Here is a link to it:
No, it does not distort until levels get quite loud. This is essentially the same as what the telephones utilized for nearly a century so nothing new.
I did publish a simple RF AGC circuit in January 2021 page 33 (since improved) but is not applicable here. Hans will eventually implement AGC in the QMX as a superior firmware feature. This is a true Software Defined Radio and the audio processing is entirely digital, making Automatic Gain Control just a software code entry. Values beyond a selected level are simply re-mapped to provide low distortion compression. Just like Flex and the other "Big Boys" do.
In the meantime, you might try an external jack (if you don't want to use a speaker) with the resistor and limiting diodes. It's cheap and effective. Try it yourself and see if it works. There will always be naysayers and detractors but I always advocate trying something just to be sure. Especially something so simple and cheap. Pennies really.
It's a hobby. Have fun!
72, Don
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QDX 80M Band Sweep Question
This is the band sweep of 80M on my QDX. I'm wondering if this is normal:
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What do the RF Plots look like?
-mike/w1mt
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Re: Relationship of VDD and VCC
The way I deal with this is to name my supplies with the actual voltages, e.g., +5V, +3.3V, etc. If there are analog and digital supplies at the same voltage, I use +3.3V_A, +3.3V_D. There’s absolutely no confusion with this naming convention.?
Tony - AC9QY
Hi Kees
The component library names for things are sometimes different from the schematic net names. This is a case of that. The 74CBT3253 calls it's supply pins Vdd. They are on the +5V rail in QMX which happens to be called Vcc.
It IS all confusing...
The way I think of it - which I believe (perhaps incorrectly) to be the most common usage is:
Vcc is for bipolar transistors, C = Collector; going back half a century to 74-series TTL (transistor transistor logic) they ran off +5V so in my schematics Vcc is +5V.
Vdd is for CMOS/MOSFETs where D = Drain. And commonly or at least, often, ok, sometimes, this means a +3.3V supply. So in my schematics Vdd is +3.3V. 73 Hans G0UPL
Looking at the schematics, I thought VDD was 3.3V and VCC was 5V but they seem to be interconnected like on the 74CBT3253 schematic power pins.
73 Kees K5BCQ
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Re: QMX AGC... any progress?
On Thu, Aug 24, 2023 at 02:19 PM, N1EDC wrote:
I posted a couple days ago....
I saw that. Similar things were tried with the QCX and do work up to a point but they're not a proper solution. I'd rather not have to bodge the hardware when the problem can be sorted out gracefully in firmware. I'm sure Hans will get round to it during his daily spare 12 seconds.... ? Joking aside, this really should be a priority as there is very real potential to cause hearing damage with these sudden violent jumps in volume. Similar to KE0WVA, my day job is in music and sound production so I kinda need what's left of my hearing to stay undamaged. Cheers, Ronan?
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Re: #qmx Bringing up QMX, Nothing in display but terminal works, shutdown press does not
#qmx
OK, thanks! I'll add that to my things to try! :-)
Couldn't imagine that those delays should be normal, but it's odd
that so much else seems to work!
Paul
On 8/23/23 23:44, Rick NF6G wrote:
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Paul, maybe flashing your firmware, at that 180 mA limited
current, was marginal for getting a good flash. Your startup
delays, and failure to shutdown, sound more to me like software
issues than hardware. Fingers crossed that something simple like a
reflash, at normal voltage without current limits, and system
reset, will normalize your QMX's startup and shutdown behavior.
On Wed, Aug 23, 2023 at 10:12 PM, Paul - AI7JR wrote:
... I set my current to about 180 mA and it came up.
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On QMX, it's been suggested to put a 47v zener from drain to
ground on each side of the output transformer, to protect against
high SWR over voltage.
Wouldn't that also obviate the need for that commutating diode?
Paul
On 8/24/23 07:39, Jonathan Halterman
wrote:
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I read this with interest a few weeks ago and would be interested
in Hans' thoughts on a commutating diode across L14 and wondering
if perhaps there might be a future revision to the QDX?
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I'm not sure would have to check, but with 12v I'm getting between 3 and 4 Watts input on each band when connected to an aerial.
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Re: USB Device not recognized .... another one
#qmx
That, I don't know...
On 8/23/23 22:34, Rick Williams - VE7TK
via groups.io wrote:
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Thanks for getting back Paul.
You are correct! In my case it should then trip the current
limited supply. However, the QMX doesn't draw current at any time
and never goes over my pre-set limit?
To confirm, when I apply power to the 2.1mm connector and long
press the left encoder, the QMX should go into into Update mode
whether it's connected to the PC via? USB cable or not?
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73, Rick
VE7TK
Website:
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Re: #QMX Are these Issues?
#qmx
I'll try that!
On 8/23/23 23:06, Chris wrote:
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This isn't what I'd expect, my QMX
comes on instantly when I press the power on button. It shows
the Shut down message a fraction of a second after the long
press but doesn't close until I take my finger off, then it's
instant.
Thinking a bit I wonder about the
controls board, try powering up with just the main board and
PSUs, no display, no controls. The current should remain at zero
indefinitely. If so you might try shorting pins 5 and 7 on
JP201, the connector to the controls board. That's the same as
pressing the power on button.
All these things seem to be associated with controlling things.
Chris, G5CTH
On 24/08/2023 06:06, Paul - AI7JR
wrote:
Is there some kind of log for QMX issues? Don't want to bore
anybody by reporting what's known, or my build defect!
Here's what I'm seeing (I've got Firmware version 9 loaded,
7volts, 250ma current limit):
- On application of power, initial current is 0, but goes to
around 10ma after 10-15 seconds. Stays steady after it comes
up.
- On initial power application, power on click is ignored,
until the above 10ma step in current.
- At that point, power on click "delays" for ~10sec, then
display comes on and 150ma current draw.
- Tune knob frequency only goes up?
- Long press power click displays Shutdown, but LCD never
goes off, current (150ma) never drops.
- While "Shutdown" is displayed, band and mode can be
changed!
- Going back to 3, if the power is interrupted briefly
(maybe 200mS), device turns off. Pressing power-on click
activates immediately!
I what I'm seeing "normal" at the moment? :-)
Haven't gotten so far as to transmit or receive, either one.
(Need to read that operations manual!)
Please forgive if this is the wrong place to put this!
73, Paul -- AI7JR
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Bruce Akhurst
Lee
Don, ND6T
Paul - AI7JR