Unless you are using some exotic insulated wire, a few seconds of exposure to the flame of a butane lighter will easily burn off the enamel. After you have done that, there will be a little oxide and smutz on the wires, so a gentle pull through a folded piece of sand paper will clean that right off. Way easier than scraping, or sanding the insulation off. -Chuck Harris, WA3UQV On Tue, 25 Mar 2025 08:31:25 -0700 "Stan Dye via groups.io" <standye@...> wrote: If you didn't scrape the enamel off the newly-twisted 'A' center tap
on the right side, those two wires won't contact each other, and you
won't have continuity between the two left 'A' points - even if you
scraped the enamel off the outside of the twist. If you have the
finer-gauge wire, you can burn the rest of the enamel off with solder
and a hot soldering iron, if you have the thicker .6 wire, you need
to un-twist the A center tap and scrape the wires first, then twist.
Stan
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
On Tue, Mar 25, 2025 at 06:57 AM, Joel W9JFK wrote:
trying hard not to do a second transistor transplant. Not sure the patient would survive
Joel, when replacing the transistors 'next time' if there is one: just cut off the body of the bad transistors, leaving most of their lead-length in place and soldered to the board.? Then lay the new transistor in place, on top of the still-soldered leads, and solder the new transitor to the old leads.? Much easier, in my opinion, that cleaning out those vias.
Stan.
|
If you didn't scrape the enamel off the newly-twisted 'A' center tap on the right side, those two wires won't contact each other, and you won't have continuity between the two left 'A' points - even if you scraped the enamel off the outside of the twist.
If you have the finer-gauge wire, you can burn the rest of the enamel off with solder and a hot soldering iron, if you have the thicker .6 wire, you need to un-twist the A center tap and scrape the wires first, then twist.
Stan
|
Re: Leaving 50-watt amplifier in-line but off
Jim, are you talking transmitting through it, or just receiving?
?
Nate
N8BTR
?
|
Re: Qmx Ssb intermittent transmit.
The same with me. Smtm you need to press PTT twice to start tx.
16:35, 25 March 2025, "Howard Lamhut via groups.io" <howardlam@...>:
toggle quoted message
Show quoted text
蚕惭齿…
I have the SSB software installed version three and made one contact with good audio reports.
The only thing that is strange is sometimes the radio does not go into transmit when I press the PTT in Ssb mode. In CW mode it works every time 100%.
?
--
Sent from Yandex?Mail for mobile
|
Re: Qmx Single versus double click volume.
Purely a firmware thing, I believe. When/if the BASIC comes, I want to customize the UI so that a single click of the left encoder puts the QMX into band select mode and you choose the band by rotating the encoder. And, put the mode change behind a double-click.
?
Another problem, I experience while operating is that I’ll tap the right button to end Message playback, but will get a little bounce and end up swapping the A and B VFO, which is annoying when you don’t notice and sit there wondering why the station calling you just disappeared! In fact, I might go so far as to have the multi VFO features enabled by a menu item so I don’t hit them inadvertently.
|
Re: Qmx Single versus double click volume.
Thank you Brian I was thinking about that and I will definitely give it a try. Thank you
|
Hi. You are logically inconsistent.? If I have 3 points A,B,C and A connects to C, and B connects to C, then A and B MUST show continuity to each other. I suggest you check your measurements.
73
Roger
8P6RX
Get BlueMail for Android
I managed to get through the steps to build the RWTST version of the transformer. I'm getting caught up on Step 14:
?
?
I have continuity between the secondaries. I also have continuity between the primary center tap and each of the two primary points on the left side. I do not have continuity between the two P points on the left side (i.e., the wires that were part of the hairpin loop before I cut it). Am I supposed to? Based on the wording in the instructions ("points P (P is for primary) should all show continuity to each other"), I assumed that I should have continuity between the two P points on the left side.
?
Separately, do I understand correctly that the tighter the wire is twisted, the closer I will get to optimum power? I was able to twist them quite tightly, but it made them brittle for completing the coil. I tried again with fresh wire but I'm concerned that it's not tight enough.
?
Thanks!
|
You won't have continuity between all the P points UNTIL you twist those 2 P leads together. This threw me as well for a bit.
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
No point to clean out the holes when replacing the BS170's, about all that does is damage the board with all the heat.
Just clip the new leads short and lay them flat across the top of the holes, solder them down.
Makes it easier to remove them next time you blow the finals.
?
Jerry, KE7ER
?
?
Those are plated through holes full of solder, and there is no chance the new BS170's are going to fall off the board.
What's the point of pushing the new leads through the holes?
?
On Tue, Mar 25, 2025 at 07:35 AM, Chuck Harris wrote:
While waiting on my
replacement BS170's I am carefully cleaning out the holes. I really
don't want to deal with this again.
|
I managed to get through the steps to build the RWTST version of the transformer. I'm getting caught up on Step 14:
?
?
I have continuity between the secondaries. I also have continuity between the primary center tap and each of the two primary points on the left side. I do not have continuity between the two P points on the left side (i.e., the wires that were part of the hairpin loop before I cut it). Am I supposed to? Based on the wording in the instructions ("points P (P is for primary) should all show continuity to each other"), I assumed that I should have continuity between the two P points on the left side.
?
Separately, do I understand correctly that the tighter the wire is twisted, the closer I will get to optimum power? I was able to twist them quite tightly, but it made them brittle for completing the coil. I tried again with fresh wire but I'm concerned that it's not tight enough.
?
Thanks!
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Thank you for kindly answering my question... I truly appreciate it. I suppose I could have known that Hans already addressed this, but I admit that I have been unable to keep up with messages.
?
I will run the calibration at the operating voltage. Might steal a few tenths though LOL...
?
But I truly appreciate the information, fellowship, and helpfulness on this forum.
?
73 & God bless,
Joel W9JFK
|
Re: Qmx Single versus double click volume.
Sometimes if the knobs are installed with not enough clearance for full down travel you can get double clicks.? If this seems like a possibility, try raising the knobs on the shaft a little.
?
Brien
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Rather than use the microphone input I have been running Fldigi into the USB and having some nice QSOs on Olivia. Olivia has amplitude modulation of the envelope (unlike wspr or ft8) due to how the individual tones are sent. It is not just a simple FM MFSK signal and really needs proper SSB modulation to work as designed. Looking at the time domain on my scope the envelope is just as it should be with fluctuations in amplitude during tone transitions.?
?
When I run calibration of either the QMX and QMX+ using Putty I get a lot of flat lines and incomplete graphs. It does feel like the process is working as it should. I suggest adding some hand-holding messages to assure the user of proper completion. Based on comments above I will try doing the calibration stand alone.
?
I have monitored the transmit signal using an SDRPlay RSP1A and Steve Andrews' free RSP Spectrum analyzer software. I used that to check both two-tone IMD and also unwanted sidebands on an Olivia signal. When I look at the two-tone IMD spectrum I see improvement with the phase compensation ON on some bands and improvement with it OFF on others. For now I am leaving it off and will wait to see how things develop. Amplitude compensation has only minor effect as expected. Unwanted energy from the transmitter is at acceptable levels for now.
?
It's worth noting that using the same measurement methods I can see substantial improvement (~ 15 db) when using the Pure Signal feature of the Hermes Lite 2 through a linear amplifier so I know this technique can show a good effect.
?
For right now I am thrilled to have SSB mode so I can transmit proper Olivia and will take the QMX with me to the UK for portable ops. Down the road it would be nice to set receiver bandwidth as with cw but for typical digital signal bandwidths.
?
Thanks for all the hard work, Hans!
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
IIRC, Hans already has stated that the calibration must be done at full power, which makes sense as it is a way of measuring, and compensating for, the non-linearity inherent in the final amplifier design. That would necessarily mean the calibration must be done at operating voltage. Hans has also suggested that the calibration isn't necessary, as he has included a set of constants that are pretty good in all of the cases he has tried, but that calibration will definitely improve the radio's performance.... Which for most hams means it is, well, essential... Hans has also stated that his QMX finals easily pass the engineer's calibrated finger test, which would seem to lend some credence to those whose measurements have shown the BS170 has a too low Vds to safely operate on the lower bands. Not to disparage those making such claims, but "measuring" is "changing", in the RF world.... but you gotta start somewhere. Transistor manufacture is still a variable enough process that most transistors manufactured will exceed the standards shown on the data sheets. Alas, most is not all. -Chuck Harris, WA3UQV On Tue, 25 Mar 2025 06:57:02 -0700 "Joel W9JFK via groups.io" <w9jfk@...> wrote: I had the same thing happen... QMX+ is on the bench with the BS170's
removed, and one of them indeed tested bad. While waiting on my
replacement BS170's I am carefully cleaning out the holes. I really
don't want to deal with this again.
Would reducing the operating voltage during the calibration help
prevent it again? Does the calibration depend on the actual voltage
used to be accurate. I normally operate at 12V with a low dropout
precision regulator. If I calibrated at, say, 9V, would the
calibration be accurate for use at the normal 12V?
Just thinking out loud...trying hard not to do a second transistor
transplant. Not sure the patient would survive lol...
73,
Joel W9JFK
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Joel,
?
I calibrated mine at 11.1 volts, battery voltage dropped with 3 diodes in series and it all went well. I continue to operate at that voltage and the output is slightly lower than it was at 12 volts, but it is not a significant difference. I am not worried about the last few mW.
?
73,
Jim AC9YY
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
I had the same thing happen... QMX+ is on the bench with the BS170's removed, and one of them indeed tested bad. While waiting on my replacement BS170's I am carefully cleaning out the holes. I really don't want to deal with this again.
?
Would reducing the operating voltage during the calibration help prevent it again? Does the calibration depend on the actual voltage used to be accurate. I normally operate at 12V with a low dropout precision regulator. If I calibrated at, say, 9V, would the calibration be accurate for use at the normal 12V?
?
Just thinking out loud...trying hard not to do a second transistor transplant. Not sure the patient would survive lol...
?
73,
Joel W9JFK
|
Qmx Ssb intermittent transmit.
蚕惭齿…
I have the SSB software installed version three and made one contact with good audio reports.
The only thing that is strange is sometimes the radio does not go into transmit when I press the PTT in Ssb mode. In CW mode it works every time 100%.
?
|
Re: #qmx #SSB Firmware beta 1_01_003 release
#qmx
#ssb
Jack,
? I have been having a similar issue, and found I got wider. smoother curves on 80 meters with my QMX+ if I configured the band edges closer to the actual legal band edged, then set the center frequency near the center of that, then used O to walk through each step of configuration. However, I don't know it the mathematical result is better because of that, because I didn't notice much real difference in the final SSB output, which is what this configuration is measuring. I lack proper test equipment for that and can only judge by ear. I think, at least in my case, I'm going to have to stop messing around and let people with the proper test equipment do the measurements and come up with conclusions.?
--
73, Dan - W2DLC
|
Qmx Single versus double click volume.
Very often when I do a Single click to change mode it changes band instead.
I was wondering if there’s something I can do to improve the situation. ?Is this a hardware issue or a firmware issue?
Is a common issue?
|
Howard Lamhut
Brien - KE7WB
Jim AJ8S
Daniel Conklin