Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- QRPLabs
- Messages
Search
Re: High current draw on initial power up
#qmx
#troubleshooting
OK - lets just suppose (until proven otherwise) that the backlight wasn't on.? Because if it was on, somehow you were getting voltage on the 5V VCC output without the processor running its firmware, which should be impossible without a strange failure of some sort.? And that failure would be seen by an independent test of PS#1.
?
The resistance measurements you reported look OK.? With the PS plugged in, there are some large capacitors involved, so the resistances can change based on the polarity of your probing and capacitors charging.
?
A measurement of the voltages on? PWR_ON and PWR_HOLD and 12V and VDD would still be interesting data.? Yes, with a current limited supply.? And/or the results of a full independent test of the 5V smps per the description in the wiki.
?
Stan KC7XE |
Re: QMX+ SSB audio distorted on one band only
I don't think there are a set of values that will work for every build.? I tried Ellis's, and they didn't work for me, but tried several other settings and finally it worked.? Then I changed back to normal values.? Sorry, I don't have a record of either set of values.? In fact, someone has conjectured that is wasn't really the band settings that caused it to work, but instead some other factor (temperature or voltage or whatever) incident with doing the changes.
?
Note that with the release firmware, Hans added a feature to 'fill' the calibration array with valid data when the calibration doesn't complete.? So you shouldn't have any distortion on 20 (unlike in prior beta versions) even if cal doesn't complete.? So it may not be worth tons of effort to make it complete.
?
Stan KC7XE. |
Re: New QMX+ Calibration victim
On Sun, May 25, 2025 at 02:21 AM, Chris, G5CTH wrote:
something that may be because I always run with a current limited power supplyHighly unlikely.? I have run calibration several times on my four different QMX* devices, always with a battery supply that can deliver a few amps (no current limit) - and have never had a problem. You are just likely one of the vast majority who have a QMX that is not susceptible to failure during calibration.
I suspect the failures are due to some other aspect of individual builds - whether it be component tolerances, weak BS170s, or some assembly artifact - in combination with the stresses of the calibration process.
Stan KC7XE |
Re: 3 cell lipo battery, how to use it anyway
Gerry,
?
C is the capacity of the battery a decimal fraction of that is?
an acceptable charge rate.? ?IT measn you need to know the
capacity and the acceptable chrage rate for it.? Don't beat me up read?
?
An aside a 11,200 mah (largest) cell group (part of a 3S4P)
built using 2800 mah cells will accept Amps.? At? 0.4C
in that case its over 4A.? ?I'd not charge at that rate so?
I'd use a 5 hour rate C/5 or lower.? The data sheet
suggests 30% to 70% C.??
?
I've worked with GAN mosFets and that was 10 years ago.
The ones I used easily ran at 15mhz very high speed 20W
switcher.? The TI driver chip was the real limiter.? The GAN
devices were froom EPC.
?
And yes they can make very efficient amplifiers.
They are optimized for switching and with very low RDSon
and fast switching speeds they don't get very warm.
Never tried them in a linear class A or B format.? Cooling
a beamlead chip 120x40x 60 mils would be a mounting
challenge?for most.? One would hope for a flavor of a
flange package.
?
?
Allison
------------------ Post online only,? direct email goes to the bit bucket. ?
? |
1) I have found that the low level sound card output to wsjt-x works fine.? But if you want to increase it, you can use the audio level adjustment per band in the Band Configuration.? See the operation manual.
2) I haven't tried Hamlib 4.7 yet, but in all hamlib versions through 4.6.2, the mode CAT commands for digi mode are not done correctly for the way QMX works.? You should set wsjt-x radio mode control to 'none', as illustrated in the QMX operation manual, and set it directly on the radio (also set 'split' to none).? Since receive AGC is not implemented on Digi mode, you don't see any receive signal strength on the QMX S-meter.? So you just need to use the wsjt-x display.
?
#2 could be 'fixed' in QMX firmware, but QMX CAT works as documented.? Hamlib has not yet implemented QMX commands properly, they just use the similar Kenwood commands.? In my opinion, hamlib is where it should be fixed - QMX VFOs and modes don't work quite the same as Kenwood's. |
I have started using fw 1.02.000 to do some FT8 via WSJTx. Works but:? 1) sound card out to WSJTx input is a bit low, reads in the 20 to 30 range (on WSJTx) when normal range is about 40 to 60 and there is no sound card rx out level adjustment that I could find in the radio.? 2) The WSJTx Mode settings need to be worked over some. Data/Pkt puts radio in Digi, but does not allow tx. USB puts radio in USB, but does not output rx. None works, but you have to set the radio for Digi and Digi never shows any rx level on the radio LCD. Don't know whether this (item 2) needs Hamlib driver, or radio fw, work to fix. I am using latest Hamlib 4.7 (64 bit). |
Re: 3 cell lipo battery, how to use it anyway
Realistically, I'm hoping they could do a couple hundred Watts out at up to 14 mhz.
It's a very small package.
Hard to dissipate switching losses.
?
Jerry, KE7ER
?
On Sun, May 25, 2025 at 03:51 PM, Jerry Gaffke wrote:
|
Re: New QMX - observations and best QSO
Many if not all cell phones have an ESD shunting inductor right across their antenna input, either a choke or incorporated as a tuning element.
All of the properly-designed tube amps I've run across have a choke across the output to ground to avoid a DC blocking capacitor failure putting anode voltage on the antenna.? Ouch.
?
73, Don N2VGU |
Re: QDX Low Receive but Xmit fine
In the Terminal program.... Audio gain for each band configuration.?
"Audio gain (dB): 54 is the default. Valid values for the parameter are 0 to 99. This makes it easy to choose a gain by band - which is often useful to get WSJT-X and JS8Call perfectly happy on each band without needing to manually fiddle with gain adjustments when changing bands. WSJTQMX operating manual; firmware 1_00_009 57 X and JS8Call documentation recommends when the band is empty, the signal strength meter on the bottom left should be at about +30dB." |
Re: 3 cell lipo battery, how to use it anyway
Allison,
?
This business of giving the charge rate in Amps as a fraction of C
which is a measure of battery Amp-Hours is just wrong.
The units don't agree!
I assume the convention was introduced by somebody that flunked physics.
?
Anyways, I was hoping you might ask some questions about that $0.04 GanFET
in the other thread.? Near as I can tell, two of those should make?
a dandy legal limit amp.? Probably? fine at 4mhz, but cooling
those suckers at 30mhz might be an issue.
?
Jerry, KE7ER
?
?
On Sun, May 25, 2025 at 03:21 PM, ajparent1/kb1gmx wrote:
|
Re: 3 cell lipo battery, how to use it anyway
Jerry,
?
We need the people that don't know to ask questions as then they read it.
?
>>Some may not know what you mean by "I charge them at .4C".
This tells us the rate you charge your battery in Amps, where 1C theoretically is the rate
at which a discharged battery will fully charge in one hour.??
?
C is the battery capacity.? Rare is it to charge at 1C for my LG cells that?
would make them very hot!? Often I charge at 8 or 10hour rate as it generally safer.
?
>>You said:? "Li tech can generally dump very large currents into a short?or worse overheat
and go into runaway ( creates a conflagration) resulting in fire."
LiPo chemistry can run away on you, LiFePO4 pretty much never does and is much safer.
Both can dump out some incredibly large currents when shorted, but then so can lead acid.
Have never had an accident with Lithium and have used a lot of it.
?
Neither have I.? But I worked with an engineer that tested that on a 5Ah pouch cell and
it was spectacular.? I found a shovel and tossed it out a window and watched burn
for 5 minutes.
?
>>>Experience:? Lithium from thumbnail sized pouch cells up to the DIY 48v 58kwh off grid bank
of?sixty-four 280 AH prisimatic LiFePO4 cells that's running the house as I type.
?
Then again I have 150AH flooded NiCd and with 7/8th inch terminal a short is amazing
I used that set of 10 (13.5v) to do some DC welding on 1/4" steel plate . That was
somewhere north of 125A.? ? High power does get respect.? ?Those cells have run
the station off grid for the last 14 years and still going strong.
?
I'm adding off grid? house lighting off 4x LFE for 5100 watthours.? They will be solar
charged.? Next iteration will bump that to 10KWH,? ?Those are 100ah 12V LFE so
care and lots of fuses are a good thing.? ? I cant divorce the power company as
all electric kitchen.? But I can seriously cut the bill.
?
--
Allison ------------------ Post online only,? direct email will go to the bit bucket. |
Re: QDX Low Receive but Xmit fine
I have looked at both the Terminal and Radio settings menus for Audio>Digi and Audio>SSB and can find no rx (sound card) out level adjustment. This is running fw 1.02.000. And, nothing is discussed about such an adjustment in the three versions of QMX operation manuals I have checked. If you can find such an adjustment, please post what and where it is in either settings screens. |
Re: QMX I/Q question
#qmx
On Sun, May 25, 2025 at 01:45 PM, <randal007@...> wrote:
Yes, you can do this for SSB just like for CW. ?
You cannot do it for digital modes, because the single USB audio device is used for demodulated audio to/from the computer.? You can't send both IQ and demodulated audio. |
I'm not sure if I've already stated this, but please count me in for the group buy for V2.0 of the QMX+ ABS mod. Tks es 73, Larry K3PEG On Sun, May 25, 2025 at 2:16?PM Mitch NK3H via <mitch=[email protected]> wrote:
|
Re: SSB Calibration question
It is fine the way it is.
Hans recently explained that during calibration the QMX operates as a transmitter and receiver.? The calibration problem is that the receiver sensitivity is too high.? Hans's software works to reduce the receiver gain as best it can.? For example it selects a band pass filter from another band to reduce gain.? If these tricks are not sufficient then the calibration will stop for that band.? Fortunately the transmitter is still very good with a partial calibration or uncalibrated.
Be happy! |
Re: QMX I/Q question
#qmx
I thought that I/Q was done over the virtual audio device, not the COM ports. (It's sent like stereo audio, with I on one channel and Q on the other.) To do both decoded audio and I/Q at the same time you'd need a second virtual audio device. If you want to do digital modes alongside a panadapter, it should be possible to use a virtual tee audio device on the computer and do both the panadapter and the digital processing there. Send the virtual I/Q "audio" to the tee, and from there to both an SDR program (for the panadapter) and a digital program (Fldigi, WSJT-X, etc). You'll want at least a mid-range laptop to run both?programs well at the same time. On Sun, May 25, 2025 at 4:45?PM randal007 via <randal007=[email protected]> wrote:
|
to navigate to use esc to dismiss