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QMX and power bank PD

 

Is the QMX itself in any way capable to negotiate the required voltage with the power bank PD?
In other words is a 12V trigger cable required or not?
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I feel more comfy with a trigger cable as it steers away from any negotiating.
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73 es dx
 

You need a trigger board or cable. Just make sure to plug it in to your PD power bank first, so it will make the negotiation before plugging into the radio.
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73, Dan - W2DLC
 

Thank you Dan, your input is much appreciated.
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73 es dx.
 

Hi,
A few features/quirks that I have noticed with several different PD compatible power banks.
? ? ?All power banks will automatically turn off after a time out period if the load is below a certain level. This is to prevent the battery draining when the power bank it not in use.
? ? ?On one of the PD power banks, it does not instantly negotiate to the trigger setting for its USB-C PD port when using the ON/OFF button on the power bank.
? ? ?On a different PD power bank, if set to 12V, it tends to shut off and restart if there is a high in-rush current when the target load it turned on.

The QMX should not present a high in-rush current, so I would not expect any issues with the power bank being at the trigger voltage before turning on the QMX.

Whilst USB PD and QC provides a handy solution for powering the QMX and other devices, its primary use case is for a charging technology, and the points noted above are not generally a problem.

73, Dave
 

I will add to what Dave has written that I don't recommend the PD triggers with the voltage and amperage indicators built in. The generate a small , but regular RF beep noise un the radio every time they change read modes. Instead, get one of those small panel ammeter/voltmeters and mount it in a mint tin to carry with your kit.
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73, Dan - W2DLC
 

Thank you gentlemen, knowing this I decided to not bother with a power bank PD solution.
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73 es dx
 

Gust, I didn't mean to put you off from trying PD power banks. They do work quite well. I and others on this forum are using them successfully. All solutions have quirks. You just need to be aware of them. The advantage of a power bank is that you can also use them to power other equipment with different voltages and connection types. It's a versatile and flexible solution.
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73, Dan - W2DLC
 

I use exclusively a power-bank and simple PD trigger cable for my QMX and QMX+ power.? One is 12V, one is 9V.? They work flawlessly.? And the small Anker 10000mAh power banks I use are smaller than the QMX, and have enough juice for several hours of continuous operation.? Don't hesitate to use this very convenient solution.
Stan KC7XE
 

I've patiently tried several.? Once negotiated the quality or not of? the? 9V? 15V etc is from the wall charger supply and as good as that is

Problems? ?The cable may output any available 'lower than requested' voltage if the wall charger socket negotiation fails or the wall charger socket doesn't do that particular nominal voltage.
e.g. I have a 20V trigger cable that gives 15V if plugged into one USB-C on my dual charger and 20V on the other (The Port PD capabilities vary) .?
Plug it into an old fashioned wall charger and out pops 5V

This can get confusing so do I end up tying the right cable to the right charger?? ?I'd rather buy a dedicated supply . .
 

I've been using NiMH batteries for various rigs for some time now, and was planning to migrate to 18650 batteries. But my Iniu LiPo powerbank with 9V trigger cable was so inexpensive and convenient to use, I doubled down and bought a 2nd one (Safuel brand) on Black Friday.

72 de Russ, va3rr

On Mon, Dec 23, 2024 at 01:05 PM, Stan Dye wrote:

Don't hesitate to use this very
convenient solution.
Stan KC7XE
 

On Mon, Dec 23, 2024 at 11:01 AM, Bruce Akhurst wrote:
This can get confusing so do I end up tying the right cable to the right charger?? ?I'd rather buy a dedicated supply . .
I agree with that - particularly since the wall chargers are also often 'noisy' in their generation of the DC voltages.
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But when using a PD Battery power bank, the confusion factor is not there, and the power is reasonably quiet.? If you are using 12V, you do need to make sure the PD battery you buy supports 12V (not all do, but it is easy to see in their spec).? All of them do 9V, per PD spec, so I built my QMX for 9V.
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Stan KC7XE
 

Bruce, the topic is using PD power banks. Not wall chargers. I've been doing it for years myself. I even wrote an article for QRP Quarterly on the subject back in mid 2020. Wall chargers are indeed potentially subject to the condition of the power served to your wall socket. This much is true. Personally, I'd rather plug a radio into a regulated source when operating on AC, or worse, on a generator.

When I go to Field Day and operate QRP, I do low-power battery powered as the category, and I only use PD battery banks. The ones I've tried that actually supported the voltage/amperage my trigger cable is negotiating have worked just fine. In fact, the original 2020 article involved using an original QCX with the BaMaTech enclosure.?

Lots of other people have replicated my results, including one person from my local club that had a friend operate using the same trigger board I did, with a power bank that I suggested in a presentation I did for my club, the Phil-Mont Mobile Radio Club in Philadelphia. This person had no trouble operating all weekend with a decent power bank, and even charged his phone at night from the same bank.

I'd have to say it's a mature methodology at this point.
-=-=-=-=-=-=-=-=-
73,
Gwen, NG3P
 

I use a talent cell 12/3000 without any problems... in home shack I use the loading adapter of this powerbank.. works great since months
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vy 73 de Udo DF4BJ?
 

Did a search looking for this kind of assurance. I have a factory built QMX - I've not been able to use it yet - which I was able to power on using those cheap AA battery banks filled with Duracell batteries to make up the 12v.
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It's a nice little power solution, if a bit of an expensive way to go about it, even if you populate the power bank with rechargable AA batteries. So it was from there I went looking in to a power bank solution.
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Yesterday I purchased an Anker power bank and a 12v USB to DC PD cable (links below). Hopefully these should do the job safely and reliably. I also purchased one of those cheap little voltage testers just to see what power is going through to the QMX from the power bank. I'm not expecting anything super accurate, but hopefully a ballpark visual would be good (linked to it below).
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Voltage tester:
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Power Bank:
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USB Cable:

 

The USB cable is a good option to be able to use any pd power bank and not need to make a custom battery with buck converters and other kit electronics.? Also one less thing in a bag.?
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Mine runs a little over 12v, 12.3 was the max it hit, so I would expect yours to perform around that.
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The variable pd cable is also viable, just change the voltage without the radio connected as it might change to the higher, 15v, option and that is no good.
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73
Jason
 

I recommend using your voltage monitor to see what happens on the port with your 12V trigger cable, when you plug any one of the other ports into something.? Mine reduces the 12V port to 5V if I plug in a 5V device to its 2nd port.? Hopefully yours has independent port voltage switching.?
Stan
 

Nice!
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I'm using an Anker 10000mah power bank and a 9V trigger cable for a QDX. Runs for hours on it, and the power bank gets dual use when traveling.? Been flawless for me, very clean way to power in the field.
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-Nate
N8BTR
 

I received the cable and voltage monitor yesterday. Both appear to be good quality for the price paid. I should have the power bank by the end of next week.
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Noticed though that the 25k one doesn't have PD. I mistakenly thought it did. It does output 12v 3a though so should be OK with the PD USB cable?
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In half a mind to return it and get the 27.5k one with confirmed PD 3.1, though its �142 vs �99.

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