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QMX+ new asssembled powers on but makes 'chuffing' sound on receive on CW?

 

开云体育

Hello i have received my assembled QMX+ a few days ago and go the power cabled assembled feeding this unit with 11.80v of dc. (12v model)?

I can putty into it and see the hardware tests pass, the data sheet shows all good on all bands.?

It powers up and down fine. I have not xmited w it yet.?

I can viewed the manual that i downloaded and printed out for vx.0027 of my software?

Still not sure of how to operate it.?

When i turned on practice mode or keyed i get a continuous series of dahs all the time. Even with key and cable disconnected. ????

If i put the unit in vfo mode it seems to go away. Volume., are and band changes seem ok.

I got thsi to stop but not sure how???

on any band cw i get a continuous audio chuffing sound like its sampling or some such.?

I can use some help or guidance on this and i am not transmitiing until i get this sorted out.?

Can i or did i change a settting in the config when i puttyed in?

Maybe its my ignorance of how it operates??

Thanks in advance?
Charlie k2cmc






--
?
Charlie C. ?- K2CMC
LICW/SKCC/NAQCC?
Re: Tariffs?

 

Just got my QMX+ last week in the US; DHL at least at the time didn't charge any brokerage. It's under $800 and so the de minimus applies.
As others have noted, when I lived in Canada dealing with those import fees from the Fedex, UPS and DHL cartel was much, much worse. The only carrier in Canada that was at all reasonable with fees was Canada Post, but it's a lot slower to ship through standard post.

Re: Here's hoping for QMX+ v2

 

On Thu, Apr 10, 2025 at 11:36 AM, George Korper wrote:
I purchased an amazing $140 mini PC and use a USB cable.
Please share the details.
Thanks and 73, Don N2VGU
Re: Tariffs?

 

I think you will be OK. Nothing has changed for US. Relax.
Re: Here's hoping for QMX+ v2

 

I'm using this amazing and cheap PC using a Raspberry Pi4-B with 8GBit RAM and Rasbian OS (a Debian Linux OS) sold at the low price of US$219 and working well. It has a choice of 2 OS to boot and I added to the original Rasbian OS the HamPi OS, the latter being a Hamradio Linux OS with all necessary Ham radio softwares installed.
?
73 - Pierre - FK8IH
QMX+ with Elecraft KXPA100 amp..;-)

 

Ok,,,, just for fun I thought I would try my QMX+ with my KXPA100 amp and *it works great*... puts out about 50 watts with QMX+ driving it.
?
I made my first SSB contact in QRP mode on 20m the other day but since the bands are not that great and I have this amp normally hooked up to my KX3 I thought I would see how hard it was to get working... EASY.. just set the PTT on each band to "grounded" and I have a TRS-to-RCA breakout cable (not sure I have that but...) once I figured out which RCA plug was which, I just plugged it into the KXPA100 and bingo! ?Plus since the KXPA100 has an ATU built in I can use that as my tuner !
?
Pretty cool...just wanted to toss that out there in case anybody else was thinking "QRO".... ?
Of course.. NOT a cost-effective solution...;-)
?
Mark
Updated Wiki Page: QMX QMX_plus debugging environment #wiki-notice

Group Notification
 

The wiki page QMX QMX_plus debugging environment has been updated by @Ludwig_DH8WN <DH8WN@...>.

Compare Revisions
Re: QMX display unususal problem #qmx #dispay

 

Marek, did you check when displayboard is connected to the mainboard and also the displayboard alone?
2 - 3 7k is ok, my fault.
?
73 Ludwig
Re: QMX display unususal problem #qmx #dispay

 

Hi Ludwig,
?
Thanks for suggestion and info. I have measured resistance between all pins (2-3,3-4, 4-5....) and except pin 2&3 resistance it in Mohms, usually 5-12MOhm. However between pin 2-3 I have only 7kohm the same value as between pin 1-2. Is there any significance in this values?
?
Thanks.?
?
---------------------------------
73 de Marek SP9TKW
QMX+ issues on 1st operation?? #12v #anomaly

 

Hello i have received my assembled QMX+ a few days ago and go the power cabled assembled feeding this unit with 11.80v of dc. (12v model)?
?
I can putty into it and see the hardware tests pass, the data sheet shows all good on all bands.?
?
It powers up and down fine. I have not xmited w it yet.?
?
I can viewed the manual that i downloaded and printed out for vx.0027 of my software?
?
Still not sure of how to operate it.?
?
When i turned on practice mode or keyed i get a continuous series of dahs all the time. Even with key and cable disconnected. ????
?
If i put the unit in vfo mode it seems to go away. Volume., are and band changes seem ok.
?
I got thsi to stop but not sure how???
?
on any band cw i get a continuous audio chuffing sound like its sampling or some such.?
?
I can use some help or guidance on this and i am not transmitiing until i get this sorted out.?
?
Can i or did i change a settting in the config when i puttyed in?
?
Maybe its my ignorance of how it operates??
?
Thanks in advance?
Charlie k2cmc
--
?
Charlie C. ?- K2CMC
LICW/SKCC/NAQCC?
Re: QMX+ with 100 amp/hour lithium iron battery

 

Hope you’ve got your fault protection sorted.?
Prospective short circuit will be 10kA and an auto fuse ain’t going to stop that arcing ..
Re: QMX+ with 100 amp/hour lithium iron battery

 

"I built my QMX+ for 9v, then installed an LM7809 inside so it will accept 10-30vdc input. That solves the over-voltage problem (that killed my first QMX) but doesn't allow for adjusting the power output as discussed here."
?
It generates slight RF noize. Which is annoying.?


----------------
To: qrplabs@groups.io (qrplabs@groups.io);
Subject: [QRPLabs] QMX+ with 100 amp/hour lithium iron battery;
10.04.2025, 21:13, "Tom - AJ8X via groups.io" <tom.metty@...>:

I built my QMX+ for 9v, then installed an LM7809 inside so it will accept 10-30vdc input. That solves the over-voltage problem (that killed my first QMX) but doesn't allow for adjusting the power output as discussed here.
?
In hindsight, I like the adjustable buck-boost idea to solve both problems.
?
Re: QMX+ with 100 amp/hour lithium iron battery

 

I built my QMX+ for 9v, then installed an LM7809 inside so it will accept 10-30vdc input. That solves the over-voltage problem (that killed my first QMX) but doesn't allow for adjusting the power output as discussed here.
?
In hindsight, I like the adjustable buck-boost idea to solve both problems.
?
Re: #qmx #SSB Firmware beta 1_01_003 release #qmx #ssb

 

This is set by the SSB drive level parameter (900 drive level is equivalent to 90%), as described on the SSB beta page.
So if I understand the description correctly, no, the modulator voltage will not exceed that set value.
Stan KC7XE
Re: QMX+ with 100 amp/hour lithium iron battery

 

Thank you everyone for such prompt responses.? A buck converter is on its way!
--
Jim, W7EZN? ? 73!
Re: QMX and power bank PD

 

The 12.01V is safe.
But are you saying that the voltage is dropping to 8.64V when you transmit?
This is safe, and will work, but will give you lower power-out.
How and where are you measuring this drop to 8.64V?
?
The voltage should not drop nearly that far, it should drop at most only to about 11V with a nominal 1m cable, if the battery is fully charged and can supply the current. ?The QMX will draw just under 1A at 12V during transmit.
?
This measurement suggests that the combination of your cable and your power bank can't supply a full 1A at 12V.? This should be easy for most power banks, so there may be something wrong with your cable or power bank.? But it should work with your QMX as-is, just lower power out.
?
Stan KC7XE
?
Re: QMX+ with 100 amp/hour lithium iron battery

 

YES!

Mandatory.

Roger
8P6RX

Get
On 10 Apr 2025, at 13:46, "Jim - W7EZN via " <yahoo.com@groups.io target=_blank>jhowell39=@groups.io> wrote:

Just about to finish my QMX+ build and I have a voltage question.? The kit was built for 12 volts.? I have a 100 amp/hour lithium iron battery for vhf base station emmcom backup.? At full charge, its just north of 14 volts.? Would it be wise to install a buck converter in the battery box to limit voltage out to 12 volts for the QMX+?? ? Thanks in advance - I really don't want to fry this little gem.
--
Jim, W7EZN? ? 73!
Re: QMX+ with 100 amp/hour lithium iron battery

 

Yes you should limit the voltage to 12V. A buck converter or just simply put some diodes in series will do the job.
--
73, de BD8BTE
op: Lun Yang
Re: #qmx #SSB Firmware beta 1_01_003 release #qmx #ssb

 

In normal operation the modulator voltage seems to be 90% of the main power, does the modulator voltage increase above that for the peaks of SSB?
Re: QMX+ T507 winding direction?

 

If you use a binocular toroid isn't there also coupling between the two transformers?
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