Re: Available Hand Mics for QMX SSB ?
Don,
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Being old and not knowing any better, I think that's very cool.
Could swap in a different microphone element easily enough, I'm sure there's plenty of room.
Here's a G5 handset for $44.95:?? ?
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Jerry KE7ER
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On Wed, Mar 26, 2025 at 10:56 AM, Don, ND6T wrote:
Just for fun (what else?) I connected up an old Western Electric G5 push-to-talk headset. IT WORKS!? Yes, it is a carbon microphone. Yes, it sounds like a carbon microphone. Just like a telephone. Like what we used for a century and didn't know any better.
And yes, the receiver sounds great.
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
On Wed, Mar 26, 2025 at 10:13 AM, Chris wrote:
Like with the last update months ago, I can't get the QMX to appear as a USB storage device. Please help me with the order of the steps:
- Connect USB cable
- Turn on
- Menu - Update firmware, follow prompts.? QMX appears to shut down but QMX drive appears on PC.
- Move new firmware file to QMX folder.
- Wait a minute or two.
- If the QMX doesn't start cycle power and try starting.
That seems to be it.
Chris, G5CTH
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Re: QMX+ Strange Audio Artifact - Help, Please...
Jim K7TXA wrote… Any other suggestions? What insects were hatching? You could try a different fly next time. -- 73 Keith VE7GDH
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Make sure the USB cable is attached to both your QMX and computer BEFORE you turn on the QMX.? This is important.
Then activate the firmware update menu.
When doing so, in some cases (for some unknown reason) the QMX may turn off and the USB storage device will not pop up.? If this happens, simply press the power-on button, and the USB storage device should then appear.
After dragging the new QMX firmware file (make sure you unzip it first) to the QMX USB storage device window, the QMX should reboot after a few seconds into normal mode.? But sometimes (again for unknown reasons) it again powers off and doesn't auto-reboot.? If this happens, just press the power-on button again, and you should be operational with the new firmware.
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These failures to reboot during the firmware update process seem to happen on specific QMX units, so if it is happening on yours, it may always happen.? I have one that does that, another that reboots properly.
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Stan KC7XE
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I find this terminal to be absolutely simple, it just needs to be run on a Chrome based browser.
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Joel
N6ALT
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Re: Available Hand Mics for QMX SSB ?
Awesome.
--
73, Dan - W2DLC
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Re: Updated Wiki Page: QMX QMX_plus SSB settings
#wiki-notice
Rick, good idea. I'm testing something theses days and won't do a reset in the moment. But after finishing the tests I will do so and add the information.
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73 Ludwig
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Re: Available Hand Mics for QMX SSB ?
Just for fun (what else?) I connected up an old Western Electric G5 push-to-talk headset. IT WORKS!? Yes, it is a carbon microphone. Yes, it sounds like a carbon microphone. Just like a telephone. Like what we used for a century and didn't know any better.
And yes, the receiver sounds great.
Woohoo!
72, Don
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Re: Debugging BS170-related issues
Steve, all of those points should be square waves.? As a check, look at the input of IC502, it is a square wave from the clock gen chip.
And check that your oscilloscope and its settings can really resolve a square wave at these frequencies.? It is not uncommon for an oscilloscope to see a square wave as a sine wave if you have a low-bandwidth probe and/or oscilloscope.
Stan KC7XE
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Re: QMX+ Strange Audio Artifact - Help, Please...
Stan - running at 12.0 volts. I was getting nowhere near that reading with my DMM.
toggle quoted message
Show quoted text
On Mar 26, 2025, at 11:39?AM, Stan Dye via groups.io <standye@...> wrote:
What input supply voltage were you using when you made those measurements?
D502 should have a square pulsed signal from about 0V to almost the supply voltage, which should average to a small constant DC voltage when measured with a DMM.? C504 should have a relatively clean constant DC voltage, at about 2V.
So something is likely broken here.? Since L501 has continuity, it is likely the diode or capacitor.? Jeff would know better than I.
Stan KC7XE
-- Jim / K7TXA
Eagle, ID
SKCC 10447T
BUG 301
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Re: QMX+ Strange Audio Artifact - Help, Please...
What input supply voltage were you using when you made those measurements?
D502 should have a square pulsed signal from about 0V to almost the supply voltage, which should average to a small constant DC voltage when measured with a DMM.? C504 should have a relatively clean constant DC voltage, at about 2V.
So something is likely broken here.? Since L501 has continuity, it is likely the diode or capacitor.? Jeff would know better than I.
Stan KC7XE
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Re: Debugging BS170-related issues
Hmmm....
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What I'm seeing doesn't make sense.
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All 4 BS170's have been removed.
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Key down, I'm seeing dirty sine wave at the point where the gate of Q503 and Q505 connect (Output of IC503C and IC503D) . A cleaner sine wave at Q504/Q506 gate point.
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At the output of IC502 I am seeing a pretty clean sine wave, key down. I didn't check IC501, because I don't want to accidentally short the scope probe to IC203.
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73,
Steve, N2IC
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Well, that would explain it! Thanks for the correction!
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Paul
On Mar 25, 2025, 22:43 -0700, Stan Dye via groups.io <standye@...>, wrote:
Menu -> SSB -> Input -> Ext. Mic
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But it sounds like your mic cable is wired backwards.? Mic signal needs to go to ring, ptt to tip.
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Re: QMX+ Strange Audio Artifact - Help, Please...
Back from the trout trip. Sunburned, and tail between legs - didn’t catch a thing. But my two buddies were able to net three very nice 3-4 pound rainbows. Yeah, that’s BIG! Maybe next time….
Anyway, just got done messing with the QMX+ and I wish I could see something conclusive. Interestingly, the “331” inductor that I thought was broken was L101.
Per your suggestions, I have continuity between the + of C504 to the + of D502, so L501 is not broken.
Since I thought L101 was hosed, I also checked the + of C107 to the + of D106, and the neighbor of L101 (L102) from the + of C106 to the + of D107. Continuity there also.?
I applied power and measured the voltages to ground from the + of C504 and D502 on key down. Both showed about 2.9vac. I also measured it as DC and it jumped all over the place from 1 v to 5 v.
I hesitate to remove C505 to check it but if you think at this point it is worth doing, I can give it a shot. What’s the worst that can happen? :-)
Any other suggestions?
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Show quoted text
On Mar 24, 2025, at 10:17?PM, Jim Bennett / K7TXA via groups.io <w6jhb@...> wrote:
Stan and Jeff - thanks for the hints on how to proceed. Got a trout fishing day coming up on Tuesday so it’ll be Wednesday before I can get back to the rig. Will post back results.
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--
Jim / K7TXA
Eagle, ID
SKCC 10447T
BUG 301
-- Jim / K7TXA
Eagle, ID
SKCC 10447T
BUG 301
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Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Like with the last update months ago, I can't get the QMX to appear as a USB storage device. Please help me with the order of the steps:
-Turn on
-Establish a USB connection
-Go to the Firmware Update menu
73 Chris
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On Tue, Mar 25, 2025 at 09:11 PM, Chuck Harris wrote:
if you use something exotic, such as a
ceramic insulated wire, my tip about using a common lighter
won't work.
You may not know it, so I will help you: You are using an
exotic wire.
Please avoid using personal attacks, Chuck.?
Some facts:
1- I can assure you again that I am not using exotic wire.
It is this:
It turns out that you can buy inexpensive wire that has has high temperature enamel.? It is made for motor windings.
It certainly is not ideal for winding toroids for qrp.? And the enamel will NOT burn off with a simple lighter.? Get some. Try it. Or not. But I have it, and I have used it for winding toroids for ATU kits and transformers. ?
2- I do use the kit wire supplied by qrp-labs for my qrp-labs kits.? The smaller diameter wire provided will indeed burn off with soldering or a lighter - it is of a thermaleze type.
3- For the older kits with the .6mm wire, here is a quote from Hans' transformer winding doc: "If using 0.60mm wire, scrape the wire enamel from this 1cm section. The enamel on the 0.60mm wire will be very difficult to remove using heat; so it is better to scrape it or sand it."?
4- I agree with Hans.? I don't think that wire had a thermaleze type insulation, either.
5- I, too, have recently retired from a 40+ year career of electrical engineering design/build/test.? I'm not an expert with RF circuits, but I do know my wire and how to use it.
Stan KC7XE
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If you have a QMX+ then there's lots of room to experiment. It's your radio, so have at it.
--
73, Dan - W2DLC
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Re: Debugging BS170-related issues
It should be a reasonably clean square wave from about 0V to about 5V, at your transmit frequency.? All corners of the square wave may be rounded a bit if your finals are installed.? Try measuring on the lowest band your device supports, since it is easy for many inexpensive scopes to distort higher frequency waveforms.? And make sure your scope probe is grounded to the board.? The failures I have heard of in the driver part before result in lower voltages coming out of one or more pins, but there may be others.
Stan KC7XE
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Re: Available Hand Mics for QMX SSB ?
Hi Paul,
?
I printed the , so I can attach a foam to it.?
--
73, de BD8BTE
op: Lun Yang
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I did a little bit of SSB POTA hunting with my QMX and a K6ARK mini-mic I had built for a (tr)sdx awhile back, made two solid contacts on 20m!
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For whatever reason, my voice usually requires some boost in mic gain on SSB; I set gain to 75 and am experimenting with Mic AGC Off or On, but generally the sound is pretty good. Nice work, Hans!
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Joel Caulkins/N6ALT
Daniel Conklin
Don, ND6T
Paul - AI7JR
Chris