Re: Help with partially fried QMX
On Wed, Apr 2, 2025 at 08:29 PM, VA2OJD wrote:
the middle, radiating contact of the BNC is connected to ground via T507??
Yes, of course.? In most radios with an internal SWR meter.? But this is DC ground.? RF flies through the transformer almost untouched.
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On Wed, Apr 2, 2025 at 07:43 PM, Rick Hill wrote:
Does anyone know if the GPS module disciplines the clock or VFO frequency
The clock, yes.? The VFO freq, no, if I understand correctly.? That could be added to a future firmware update, I believe.
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Yes it does on my QMX+. You might check your battery.
John KK4ITX? ?Each mistake is a learning opportunity.?
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On Apr 2, 2025, at 10:44 PM, Rick Hill via groups.io <6xraytango@...> wrote:
? I have noted that my RTC is wildly inaccurate, gaining 7 minutes overnight. I have removed it from the display...do not really need it. Does anyone know if the GPS module disciplines the clock or VFO frequency ??
de VK6XT?
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GE Martin,
I would start with the settings that are in the manuals, then;
* Turn the volume down! If too loud it’s hard to translate.
* Next adjust your filters correctly?
* Try to use the Noise Blanker
The rig needs to hear the cleanest signal you can feed it. When it’s not clean you get “*”.
Sometimes you have to move slightly off frequency to get the best results.
You can usually achieve 70-90%, you have to be able to fill in the blanks.
The QMX+ seems to be better than my 3 QCX rigs but I am new with the QMX+.
Hopefully this helps,
John? KK4ITX? ?Each mistake is a learning opportunity.?
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On Apr 2, 2025, at 11:10 AM, Martin DK3UW via groups.io <m.sellschopp@...> wrote:
? Hi My reader is very erratic with a lot of *. can someone who has a good setting let me know how they are please
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Martin
DK3UW
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Re: Help with partially fried QMX
Hi Steve.? Thanks.
So even the CENTER of the BNC?? the middle, radiating contact of the BNC is connected to ground via T507?? MyBS170s look fine.? Is there a way to test them?? It makes sense that they would pop first, but i've no idea how to test them.??
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Is there a single spot, somewhere on this forum, where it lists key measurements to check when troubleshooting?? I must have made Google a million dollars in eyeball hits in my searches over the last week.
?TNX again!
JD
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Re: QMX+ rev 3 freezes shortly after boot
Alright! I've got some updates.
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I pulled off the front panel and did a close inspection of the display connections, didn't see anything obvious but cleared out some plastic and some small fibers, possibly from my sweater or ambient dust.
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Checked R110 and R112, both of those appear to be in fine condition. During normal operation both read at around 1.6V.
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Checked resistance between VDD & VCC. When my positive probe was on VDD & ground probe was on VCC, the resistance started at around 3.2kΩ and maxed out at around 4.46kΩ.
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When my positive probe is on VCC and ground probe on VDD, it starts at 2.8kΩ then climbs up to around 6kΩ, then there's a spike up to 28kΩ, then it descends back down to and stabilizes at around 7kΩ.
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I checked D109 and it seems good as well - no obvious heating or anything like that.
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No GPS currently installed, and it wasn't installed during any of my earlier tests.
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Now for the interesting part. After checking all of the above, I turned it on and held steady for about 5 minutes. So I thought I'd try out the terminal again. This time I was able to connect! Previously, it would freeze at the exact moment I hit "enter" to initiate the serial connection. This time I was able to open the menu and even run some diagnostics! Attaching the screenshot from the diagnostics view below.
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In fact the terminal session was going so well, I thought I might've cleared up whatever the issue was. Unfortunately, it froze again shortly after that. I believe I'd entered into the RF Filter Sweep menu item and was watching the output when I saw the current jump from 0.8A to 0.20A and cut the power.
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The only substantive things I can think of that I did were:
- I unplugged the front plate and removed some melted plastic from the very top left female port of JP215
- I used the tip of one of my probes to clear out the channels between the pins of JP215, JP216, and JP201
- I took my and blew out some of the fibers I saw
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I am wondering if it's temperature related or possibly related to a capacitor somewhere(?), because it seems to perform much better after 10+ minutes of no use, vs 30 seconds to 1 minute of no use. If I wait 10 minutes or more, I can usually get a good few minutes of use, but if I only wait a few seconds or a minute after cutting power, it will either start in the frozen state, reach the frozen state after a few seconds powered on, or the screen wont power on at all, and rather than drawing 0.20A, it'll draw about 0.14A.
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I have noted that my RTC is wildly inaccurate, gaining 7 minutes overnight. I have removed it from the display...do not really need it. Does anyone know if the GPS module disciplines the clock or VFO frequency ??
de VK6XT?
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Re: Debugging BS170-related issues
Success !
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When in doubt, try the simplest thing first.
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After an afternoon spent looking for the esoteric solution, I touched up all the IC503 pins with the soldering iron.
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4-5 watts on all bands, again.
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Many thanks to Ludwig, Stan and Chuck for their help.
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73,
Steve, N2IC
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Re: Help with partially fried QMX
You will always see DC continuity from the BNC connector to ground through T507.
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For no power output, start with the BS170's. I just went through this, frying the BS170's, IC503 and Q507.
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73,
Steve, N2IC
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Re: Gibberish characters appended onto end of Message 1
Thank you very much! I've never heard of it, but I am not a techie so that's not surprising.?
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Re: Available Hand Mics for QMX SSB ?
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Re: ProgRock2 programming??
Thanks Alan, I’ll measure the xtal socket and see what’s on each pin. I’ll have to be careful to put the voltage pin on a socket with 5v regulated voltage.
73 Tom
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On Apr 2, 2025, at 1:50?PM, Alan G4ZFQ via groups.io <alan4alan@...> wrote:
?On 02/04/2025 14:59, cct314159 via groups.io wrote:
- Even though they are "rated" for "12 volts" *don't even think about running one at that voltage:* I'd avoid going above 10.0 volts. Yes, that reminds me. I tested with 12 volts and it certainly got a lot hotter than I expected.
The ones I use are fed from 5 volts and keep cool.
73 Alan G4ZFQ
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Re: Gibberish characters appended onto end of Message 1
Hi Braden
Putty is the favoured terminal software, works on Windows and Linux.
73
Roger
8P6RX
Get
OK, I'll have to find out what software goes with the QMX. So far, seems buggier than an Amish church meeting.?
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Thanks for the ideas – so a bit of probing and VDD to GND is like .5 ohms – without the smps board installed . Any ideas where to start looking for the short? ? thanks ?
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From: [email protected] <[email protected]> On Behalf Of Stan Dye via groups.io
Sent: Monday, March 31, 2025 1:24 AM
To: [email protected]
Subject: Re: [QRPLabs] Lin_reg_en #troubleshooting? Also inspect carefully the interconnect of the LIN_REG_EN signal fromthe smps card to the main board, ensuring nothing there is pulling it down.
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Re: Available Hand Mics for QMX SSB ?
Eric, I got my mic kits on Monday and put them together today. Now I have one for my KX2, one for my QMXs, and one for my tr(u)SDXs. Thanks!
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73, Dan? NM3A
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Re: Gibberish characters appended onto end of Message 1
OK, I'll have to find out what software goes with the QMX. So far, seems buggier than an Amish church meeting.?
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Re: Help ID QDX Digital voltage and band option
Evan,
LOL! I made the silly assumption that a DL would be attached.?
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73, Dan? NM3A
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Re: Gibberish characters appended onto end of Message 1
Maybe you can try to connect QMX(+) to a computer and enter/clean messages in putty, it's easier and you get visibility of the whole message buffer.
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Re: Help with partially fried QMX
I am also trying to diagnose a fried (?) board, Rev 4, ordered and built in the last couple weeks. wound for 9V.
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As posted elsewhere, i had an issue with a powerboard, replaced it, and it worked fine for about 12 hours.? made some FT8QSOs (two new DXCC for me even!), and some CW contacts and RBN showing well into europe and across US.
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But then it all just suddenly stopped.? All terminal diagnostics are pretty much exactly as shown in the operation manual, the only issue being no power out on pressing T.? What i did discover was continuity between the center pin (radiator) of the BNC connector and ground. I removed the BNC connector but the issue turns out to be with the main board. With the BNC connector removed, there is no continuity between the female center and the outer housing.
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Any suggestions on where to look first?
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Thanks in advance.?
JD
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Re: Gibberish characters appended onto end of Message 1
I figured out how to delete the entire message. Then, I re-entered the message but I am still getting gibberish sent at the end of the message that I did not enter.
The gibberish is K0****AS?
This renders the message function to be useless.?
I hope no one is listening to the CQ I'm sending.?
Buying a pre-assembled unit, I was hoping not to be doing debugging. Oh well.?
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KK4ITX John
Michael Shiplet
Braden Glett