Hello, All—

Is there anyone who knows how and would be willing to replace the Si5351 synthesizer chip in my QCX transceiver with a good one? I do not have the equipment or equipment to do the SMD removal and soldering.

I will gladly pay for your time and expertise.

THANKS!

Rick, W B 3 B I Q

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I tried powering the 3.3V line direct from my test power supply with a 250mA limit. Went into current limit immediately. Guess the CPU is slagged. :-(

Still don't know what I did, either!

Sad Paul.

On 25 Aug 2023 at 12:49, Stephan Ahonen KE0WVA wrote:

I intend to run off a car battery
inverter so I took some extra steps to
ensure thermal performance at 13.8
vs. 12. I put thermal paste between
the bss170s and the ground plane,
and a thermal pad on top to try and
conduct more heat into the washer
holding them down. Maybe at some point
ill replace the washer with an
aluminum bracket that attaches to the
inside of the enclosure to conduct
the heat out that way.

why don't you just use one of the several
BUCK converters that have been suggested
on here over and over?

That would GUARANTEE 12.0vdc into the
rig no matter what your auto generator /
regulator puts out (I've seen my car go up
to over 14v while running).

w2jc

Mine varies slightly from band to band but the highest I've seen on TX is about 1.3A from a lab supply set at 9V.

Jonathan KN6LFB

Hi Rich,

I recently completed a QMX and have a USB powerbank so I thought I would give it a try.? The USB powerbank? I have is a PD type rated at 10,000 mAh 18W.? I have a PD "dongle" connected to it so that I can select an output of 9 or 12Volts.
So, with the dongle set to 9V, I measured 9.14V output.
Running the QMX from this, I got the following transmit outputs.

80m 3.0Watts
40m 3.25Watts
30m 4.0Watts
20m 3.5Watts

Current draw was between 0.8 Amp and 1.2 Amp.? The PD powerbank is rated at 9V 2 Amp output.
So it ran the QMX comfortably and a quick receive check didn't show any significant interference from the powerbank or dongle.

Cheers,?
Glenn VK3YY.

While I await delivery of my factory-built QMX (~110 on the wait list) I am wondering what the max current consumption might be? I've got a 10,000 mAh? 5 volt USB "brick", and I'm considering using a 9 volt upconverter to power the rig.

Thoughts?

Rich, KY6O

Jerry,

you should be able to setup 6 meters in the band configuration screen.?

73
Evan
AC9TU

LIN_REG_EN doesn't start at 12 V, it's staying at 0.7 volts, so the 3.3 V rail never gets power and the uP never starts. Pull up is working, no short to ground, on this line.

See?/g/QRPLabs/message/108481,?for the whole story.

Am I SOL?

Paul -- AI7JR

Kees,
?I believe 470uF 10 V tantalums are also available in 7343, but are 1mm higher.?
--
73, Dan? NM3A

Assuming that the hardware can work at 50 MHz, how will you change the software to enable 6 m frequencies? ??

Does the waterfall change if you disconnect the antenna? Are you receiving anything or just dead?

Reboot the computer?
Good luck,?
Mike N0QBH

sorry 9 for sure.? only have a 10mhz scope but the voltages on pcm1804 when splash screen is on are ok on pin17 and 18 but nill on 15 and 16.just checking this out now

Thank you for bringing up this topic so recently. I helped me in troubleshooting once I found my fried D101. The replacement on Amazon for me is 2 days, but its a good interim fix with the delay on shipping of the new SMPS. I may still order a new board for peace of mind, but try my hand at some SMD replacement in the meantime!

Be well.
--
Alex
KM4FFB

If you are really using 8, you should be using version 9,? Version 8 was quickly replaced due to issues.? ?

Mike, check out this message from Hans??/g/QRPLabs/message/105756,?the firmware is not in eeprom but he does have some suggestions on where to look for this problem, maybe L402 47uH inductor

Hans, I can add one tips:
When installing the input power connector, push it towards the board edge.
This will increase the very small clearance to the left encoder on the control board.
Nevertheless I put kapton tape on the encoder body facing the power connector

73 de SM5EIE /Gunnar

When you connect to the pc to load the firmware ( now for the nth time) do you see two files already in the QMX ? The system should only go into firmware load mode automatically the first time, then you should have to explicitly request the update, via terminal mode, qmx menu select or by jumper wire.? Seems like the firmware is not being loaded to eeprom.?

Dr. Pedro,

Once a feature is introduced, it is in all subsequent releases unless Hans notes that it has been removed or changed.? Also, all QDX firmware can be used on any board revision.? I always update to the most recent, even for my Rev 1 board.

73
Evan
AC9TU

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