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Re: QMX+ Toasted L-518 Toroid -- Cause ?

 

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Hans, THANK YOU! ?I didn¡¯t build my QMX so wasn¡¯t aware of a 0 type of toroid in the unit¡­.. so you taught an old timer like me something new. ?It makes my day! ?64 years with a license and I am still learning. ?

Be the REASON someone smiles today.

Dave K8WPE

On Aug 11, 2024, at 1:27?PM, Hans Summers <hans.summers@...> wrote:

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Hi Bill

Always remember: "if it ain't broke, don't fix it!". Ok I know yours actually IS broken but still the radio works fine... So leave it be. Note that the -0 material is permeability zero. It's the same as winding on air. It doesnt even have any magnetic properties to restore by glueing it back together, which would otherwise be the advice on a toroid with actual permeability. The only reason for having the toroid there at all is that you can't easily and repeatably and reliably wind such a nice toroid on air. It just provides a nice convenient shape so that when I say 25 turns it always comes out at approximately similar inductance every time..

73 Hans G0UPL


On Sun, Aug 11, 2024, 20:55 Bill Jobes via <jobes=[email protected]> wrote:
My QMX+, built for 12V version, has been performing well for some weeks.? I decided to tweak the LPF toroids to see if IO could boost power a bit.
Imagine my surprise when L-518, one of two toroids for 10 and 12 meters, felt like mush when I squeezed it.
Further exam revealed it had split in four places, as can be seen in the attached photo.
I'm asking for advice on what caused the damage, so I can avoid that behavior in the future. I'm presuming one of my 12V batteries was over-charged to 13.8v, or maybe an SWR adjustment using either a T-1 or a ZM-2 'searched' into a damaging SWR range.
Since the radio still seems to function as normal, should I bother to replace L-518?? Rather than risk hole or pad damage, I'd snip this one out, and install a new one wire-to-wire.
I'd appreciate your thoughts/advice.
- Bill? W3WJ
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Re: QRP Labs xciever with SSB capability

 

I got involved with that back when and it was terrible.
I do not remember you being involved at all. But I do remember you telling everyone it ?s not good and cannot work.
Yet, here we are, uncountable uSDX and 20000 (tr)uSDX out there, and people just use it for what it was intended....
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In the end it is way better than its reputation.
See for example this video, which was recorded, using 1,5 year old firmware:
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Guido has improved SSB Quality further since then. But even with that old Version I was still able to attend the 60m emergency network.
Sometimes I think people spend too much time over theory, while they could have their answer in seconds, when they would just try it for themselves....
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73 Manuel; DL2MAN
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Re: Increase receive gain on QDX?

 

Everett,
you need to connect to the QDX using a terminal programme such as ¡®PuTTY¡¯. In the configuration setting you can increase the rx audio level per band. Default is 54, I set mine in the higher bands to 99. This will increase your WSPR level.
73 Ken G4apb?
Re: QMX+ Boost Power Out on 20M?

 

Ian?

In your table several of your 'power equivalent values' don't appear to make sense . .
Re: QMX+ Boost Power Out on 20M?

 

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Rms watts =( rms volts ^2)/50
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the ¡®50¡¯is the load impedance which must be a 50 ohm dummy load or everything is out from there
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¡­ a newer scope may measure the true RMS voltage ?for you but failing that and assuming a sinewave (so measure after the LPFs) measure peak to peak, ?divide by 2 for peak and multiply by 0.707 for the rms voltage?
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But ?A much shorter formula in this case is (peak to peak^2) /400 = rms watts?
Re: Increase receive gain on QDX?

 

On 11/08/2024 13:08, Everett-WB9FUW via groups.io wrote:
For any band I select my receive gain is about 40. How can I increase this?
Everett,

You are unlikely to notice any difference 40 is fine. There is a Terminal adjustment, see the manual.

is there any way to monitor the received audio?

In Windows "Listen to this device" but not many bother to hear digital modes, it is on the waterfall.

73 Alan G4ZFQ
Re: How to check BS170¡¯s on QMX

 

Re: How to check IC503/BS170 with DMM?



/g/QRPLabs/message/127369
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Increase receive gain on QDX?

 

Hi, I am running a QDX with WSJT-X and Windows 10.? For any band I select my receive gain is about 40. How can I increase this? The app slider doesn't work and there really isn't any adjustment in Windows sound setting.
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Am I missing something? Also is there any way to monitor the received audio? Can't have QDX soundcard and USB speakers selected at same time.
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Everett-WB9FUW
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Re: QCX Numbers?

 

Hi Mark
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Nothing really important, just curiosity. How many of each band of the QCX family have been sold? Anybody know?

Probably only I can answer this question ;-)?

Total QCX/QCX+/QCX-mini sold: 20,849

of which:

10m:? 0.04%
15m:? 0.03%
17m:? 3.6%
20m:? 33%
30m:? 9%
40m:? 47%
60m:? 1.0%
80m:? 5.3%
160m: 0.32%

Data?is somewhat approximate since sometimes people order QCX along with several Low Pass Filters for other projects; my analysis spends a little effort to clean this situation up but obviously it's not a huge priority and I can't spend the whole day examining every order individually or figuring out better ways to analyze the data, and anyway it wouldn't make more than a fraction of a % difference in any direction.?

73 Hans G0UPL
Re: straight key and semi qsk

 

Works fine on mine. I have it set to 400 mS and it does what it says on the tin.
Re: Is this a 9V or 12V low-band QMX build?

 

Cliff, you are correct.? It's a used low-band QMX, and the builder forgot if it was a 9V build or a 12V build.? I opened it up and counted the turns on T501, and it is indeed a 9V build with the standard winding.? I've been running the supply voltage low until I opened it up and counted turns.?
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The next job will be to remove T501 and re-wind it for 12V with the RWTST wind.??
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73
Mike N9OHW
Re: How to check BS170¡¯s on QMX

 

Thanks all for the feedback.? I ordered 10 BS170's on Amazon and the came the next day.? I replaced all four BS170's and the rig puts out the same power as before the finals were blown, and the current consumption in RX went down to what it was before.? I was a little surprised how similar the RMS voltage readings were after the transistors were swapped.? The same down to 0.1V.? I had expected some part to part variation.??
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I tried one of the tips someone on here mentioned, to snip off the leads and seat them in a blob of solder, so as to make the next replacement job easier.? That worked to some extent, but on some of the transistors, I just removed all of the solder and remants of the old leads and did it the standard way.? If I have to go back in and replace them, I'll have two the quick way and two the standard way, and I'll assess whether the quick way helped.??
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73
Mike N9OHW
Re: QMX+ Toasted L-518 Toroid -- Cause ?

 

No, but the buzzing is damned annoying.?
--
Wayne S.
KF7RCM
Re: My #QMX died :-( #qmx

 

Check all component for having enough space. Coils, holder, everything.
Sometimes you need to bend some thing like the metal what hold the lcd in place on its own pcb.
I had some issue while i plugged the earphone or paddel. The qmx turned off, but luckily no damage.
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Re: Audio level on a QCX+ #troubleshoot #troubleshooting #20m #audio

 

Just to note, some months back I did a factory reset to resolve some issues, though I don't see how it would play into this. Did the alignment this evening, set the frequency to 14050. What is interesting is the nulls were significantly off. At 8.7, the peak was at 10, which is where it was from day one. The I-Q Balance was a little higher than I remember but Phase Low and High had alot of room for adjustment. I went back and forth several times to get the lowest values. I couldn't test it as the band went completely dead due to solar activity. Hopefully I will get a chance soon. I am toying with the idea of selling it. I really enjoy the mini you built for me and I don't need two. Flirting with the idea of a QMX+ KIT. Anyway, Thank you for your help, I will post a follow up asap.
--
Wayne S.
KF7RCM
Re: QMX+ Toasted L-518 Toroid -- Cause ?

 

Maybe you should "fix it" with bee wax as in good old times.
Bee wax doesn't do change the values or they do?
QMX out-of-band Presets

 

Some out-of-band presets default to 3573000.
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Presets:?
15000000 WWV Time standard
12808500 KPH Maritime Coast Station
? ? ? ? ??
When attempting to load, the VFO goes to 3573000. \
These presets worked OK in FW 1_00_023.?
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(13690000 Radio New Zealand loads OK.)
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Setup:
QMX Rev. 1
FW: 1_00_026?
Band version: 80-20
Band limits: None
RX outside band: ON
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-Tom
K9AC
Re: Audio level on a QCX+ #troubleshoot #troubleshooting #20m #audio

 

Wayne, that difference is due to the fact that the chart on the manual was made using the internal voltmeter which has a very low impedance and loads down the test points. You obviously used a DVM with high impedance so it didn¡¯t load it. The voltages you reported are all very good.?

It never hurts to do another alignment just to make sure all the nulls have been found. What was your reading on the bandpass filter alignment? Is it in the 8 range??

Ron

On Sun, Aug 11, 2024 at 18:50 kf7rcm@... via <kf7rcm=[email protected]> wrote:
Here are the results:
IC-5: 1=2.8v, 2=2.5v, 3=2.55v, 5=2.56v, 6=2.5v, 7=2.46v
IC-6: 1=2.47v, 2=2.46v, 3=2.46v, 5=2.46, 6=2.46v, 7=2.46v
IC-7: 1=2.8v, 2=2.8v, 3=2.8v, 5=2.8v, 6=2.8v, 7=2.8v
IC-8: 1=2.6v, 2=2.6v, 3=2.6v, 5=2.6v, 6=2.6v, 7=2.6v
IC-9: 1=5v, 2=5v, 3=4.7v, 5=2.6v, 6=2.66v, 7=2.66v
IC-10: 1=6.5v, 2=6.5v, 3=6.5v, 5=6.5v, 6=6.5v, 7=6.5v
There seems to be some discrepancy with IC-5, pin 5 should be 2.28v instead of 2.56v. IC-6, pin 3 is 2.46v instead of 1.63v and pin 5 should be 1.55v instead of my 2.46v. IC-7, pin 3 should be 1.99 instead of 2.8v and pin should be 1.89v instead of 2.8v. IC-8, pin 3 should be 0.65v to my 2.6v and pin 5 should be 0.67v to my 2.6v. IC-9, pin 3 should be 0.65v to my 4.7v and pin 5 should be 0.67v to my 2.6v. IC-10, all the pins are 6.5 which doesn't match any of the values in the literature. I am thinking of doing another alignment from the ground up, but will hold off until I get your opinion.
Thanks, W.
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Wayne S.
KF7RCM
Re: Audio level on a QCX+ #troubleshoot #troubleshooting #20m #audio

 

Here are the results:
IC-5: 1=2.8v, 2=2.5v, 3=2.55v, 5=2.56v, 6=2.5v, 7=2.46v
IC-6: 1=2.47v, 2=2.46v, 3=2.46v, 5=2.46, 6=2.46v, 7=2.46v
IC-7: 1=2.8v, 2=2.8v, 3=2.8v, 5=2.8v, 6=2.8v, 7=2.8v
IC-8: 1=2.6v, 2=2.6v, 3=2.6v, 5=2.6v, 6=2.6v, 7=2.6v
IC-9: 1=5v, 2=5v, 3=4.7v, 5=2.6v, 6=2.66v, 7=2.66v
IC-10: 1=6.5v, 2=6.5v, 3=6.5v, 5=6.5v, 6=6.5v, 7=6.5v
There seems to be some discrepancy with IC-5, pin 5 should be 2.28v instead of 2.56v. IC-6, pin 3 is 2.46v instead of 1.63v and pin 5 should be 1.55v instead of my 2.46v. IC-7, pin 3 should be 1.99 instead of 2.8v and pin should be 1.89v instead of 2.8v. IC-8, pin 3 should be 0.65v to my 2.6v and pin 5 should be 0.67v to my 2.6v. IC-9, pin 3 should be 0.65v to my 4.7v and pin 5 should be 0.67v to my 2.6v. IC-10, all the pins are 6.5 which doesn't match any of the values in the literature. I am thinking of doing another alignment from the ground up, but will hold off until I get your opinion.
Thanks, W.
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Wayne S.
KF7RCM
Re: #qmx #qmx+ #firmware release 1_00_026 #qmx #firmware

 

Update: I went back to 1_00_025 and it was fine. Then I went back to 1_00_26 and it was fine.
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I guess I? will redownload and try again before I post in the future.?
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Especially when Windows 11 says it doesn't recognize the drive!?
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Pardon me ?
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