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: QMX and power bank PD
On Sun, Apr 6, 2025 at 11:48 PM, John Pokluda wrote:
Why on earth take the risk with an oversized barrel, even after Hans' otherwise comment?!Hans's comment is: 5.5 x 2.1 is correct.? my comment is: THIS?5.5 x 2.5mm?plug? on? works?with?no problem! Both are true you can change the plug if you want. 73 DE muhsin TA1MHS |
|
Re: QMX+ no power output, low SMPS bias current
Hard to understand measuring SWR if you truely have 0 watts out... :-)
?
Paul -- AI7JR
On Apr 6, 2025, 15:43 -0700, mitchellrlawrence via groups.io <mitchellrlawrence@...>, wrote:
|
|
Re: QMX+ no power output, low SMPS bias current
I just finished my build sounds similar to your issue?
0 watts
9.xx volts?
swr jumping a little mostly around 1.2-1.5
?
I am going to start form the bnc and work my way back through the circuit unless I find any other advise?
let me know if you discover anything!! |
|
Re: QMX and power bank PD
On Sun, Apr 6, 2025 at 05:11 PM, Stan Dye wrote:
Stan
THIS 5.5 x 2.5mm?plug? on works with no problem! other people are using it with their PDs and QMXs on POTA activities. I tried to get an ?intermittent contact just for you, but I couldn't, sry. 73 DE muhsin TA1MHS |
|
Re: Available Hand Mics for QMX SSB ?
All the mics I have assembled and tested with my QMX+ (which is now a LOT of mics) have had various results. I have not changed the default settings from the SSB firmware, but some elements pick me up from several inches away and others I need to be about about 3 inches from the mic. This is not a problem for me, I like to hold the mic close anyway, so I usually have to turn down the mic gain. Every mic element will be slightly different.
?
All the elements that I have used and tested were adequate to pick up my voice with the default settings in my QMX+ and hear it well with my Yaesu FT-710. (QMX transmitting into dummy load, FT-710 has 18dB attenuation turned on and an G5RV antenna in the back yard) I have not found one yet that I thought was inadequate for the job. I did notice a slight difference when I used a "cheap" (not inexpensive cheap, but flimsy cheap) and a nice cable. The better quality cable yielded slightly better performance. |
|
Hi all, This is my experience?with the SSB beta release. After much fear and?consternation, I took the plunge today and installed the SSB beta firmware in a QMX Rev 1. I attempted to do a calibration on Putty, but the R and O commands would not work. This could be due to my inexperience with Putty or a failure to understand the?instructions. I disconnected the?QMX from my laptop and was able to run the calibration from the Hardware Tests screen on the radio. The QMX got a little warm, but the?calibration was apparently successful. Afterward, I checked the CW power output on?several bands, and it appeared to be normal (same output?I had before the calibration). I did not put the QMX back on Putty to check the calibration curves. I tested the?SSB mode with a QRPguys microphone?kit and made 8 successful?phone contacts on 20M. Audio and signal strength reports were good. The?mic is covered by a cutdown foam windscreen purchased from Amazon, and the only mic setting I adjusted?was compression set at 5. I found the best output occurred while talking straight down into the mic held about an inch from my mouth. Probably because the mic element is a setback from the vinyl cap. I have not tried other?bands yet.? I am mainly a CW op, but after the successful SSB implementation I may have to start making more phone contacts. I'm almost embarrassed to say it was fun!? 72, Randy NR5N |
|
New firwware#firmware
So far everything seems to be functioning well. I have noticed that when using the swr tune function that on some bands the swr reading does not change while tuning an antenna and I have to turn it off then on again to get a new reading. This didn't happen before and would change as I operated a tuner.
?
Randy
VE3JO |
|
Re: Broken L512 toroid.... T37-10 (Black)
Here's one source Bill Ron On Sun, Apr 6, 2025 at 2:08?PM Bill VE4WJM via <mayberrywj=[email protected]> wrote:
|
|
Re: Swr meter in SSB mode
That's the same for me, everything is fine in CW and Digi but SSB is weird On Sun, Apr 6, 2025, 5:20?PM Barry Palmatier via <BarryPalmatier=[email protected]> wrote:
|
|
QMX+: Broken L102
I finished building my QMX+ today and on inspection I see I've broken the core of L102, one of the switching power supply inductors. It looks like both leads of the winding are still connected to the board. I'm not going to try powering it up until I get a couple of questions answered.
?
1) It looks like the core snapped off almost flush with the bottom flange, which is still attached to the PC board. The ends of the winding are still connected to the board. Would it still work if I just used cyanoacrylate glue to put the core back together?
?
2) If the answer to #1 is "no," can anyone suggest a suitable replacement inductors that's available in the U.S.? Digi-Key doesn't seem to carry anything of similar size that's greater than 220 uH. This one is 330 uH.
?
Dave, WD8CIV |
|
Re: QMX(+) Build experience, Poor Audio Filter Sweep/RF Filter Sweep/Image Sweep/ADC IQ test and resolution with new PCM1804
Karl, these results are a bit confusing to me.
If I understand, you are putting in a 14MHz sine wave signal at about 15mV, and are tuned to 14MHz.
With that setting, you should see the 14MHz signal at the input of IC408, pin 5, and on its output, but only on pins 1 and 2.? The true output is on pin 1, and it gets coupled through the shared BPF L403 to pin 2.
You should not see the signal on IC408 pins 3 and 4 or anywhere else.? If you do, you likely have a short somehow between L401 and L403, or perhaps a failed IC408.
And the signal should also be seen at IC402 pin 11.? If it is on IC402 pin 11, that would be from the above-stated short.? But since you see it very weakly or not at all on pin 11, it means something is wrong with your soldering or winding of L403.
?
The signals you are measuring on IC403 pins 7 and 9 shouldn't be there, or perhaps are from poor grounding during measurement.? And I don't think they are at all related to your input signal, if it is indeed a 14MHz sine wave.
?
So check L403 carefully, and any possible shorting to L401.
Stan KC7XE
? |
|
Re: Swr meter in SSB mode
Interesting.??
Mine doesn't do that (tested in SSB mode on both a QMX and a QMX+ into a dummy load).
Sometimes at the instant of pushing the PTT key, the SWR indicator does jump up, but then goes back down and doesn't continue to change.
Testing instead into an antenna, which shows 1.3:1 on the Hardware test / Test SWR function, I see the swr indicator go up one or two 'bars', which is correct, based on the operational manual's definition of an increment of 0.2 per 'bar'.
?
So I'm wondering what is different in your setup that changes the behavior?? It's almost as if you are looking at ALC or mic AGC rather than SWR, but I don't think it is supposed to be able to do that.
?
Stan KC7XE. |
Paul - AI7JR
Ronald Taylor
to navigate to use esc to dismiss