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QMX and power bank PD
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Don't leave USB power test meters in line when you are not actually taking measurements, and when you do, make sure no other equipment is hooked up to the power bank - either before or after the measuring device!
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Many of them measure on the ground side by inserting a resistor in line - which causes confusing and sometimes dangerous results if you connect grounds together on both sides of them.
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Also, all of them measure by inserting some sort of resistance inline to produce a voltage drop. At high currents, this will drop the voltage available to the load, and in some cases cause poor regulation.
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They're all great devices, but you need to think about their limitations while using them. They're not great for monitoring - mostly intended for specific measurement setups.
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hope this helps...
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M |
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On 07/04/2025 05:39, Muhsin TA1MHS via groups.io wrote:
You'll see 3 types of plugs.Muhsin, Others have said 5.5 x 2.5mm works, then their QMX failed. It seems risky to depend on a plug that is not the correct size. When I look at your link I say "It does not have the correct size connector, I will not purchase that." 73 Alan G4ZFQ |
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On Sun, Apr 6, 2025 at 11:09 AM, Muhsin TA1MHS wrote:
Hi? If you look into this link,
You'll see 3 types of plugs.
Only 5.5 x 2.5mm plug works with QMX.
This is not what I think, It is what I and other people are using.
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What we know/read may not be the ultimate truth
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What a waste of time
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73 DE muhsin TA1MHS
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Great comment.
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Two thumbs UP. GREG
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Muhsin is correct.? As I noted in my original reply, some 2.5mm connectors may work.? Some are designed with spring contacts, and are advertised as being compatible with 2.1mm.? And those do achieve a good contact.?
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However, Muhsin, if there are two choices in a connector for a QMX trigger cable, and one of them is 5.5/2.1mm, as is the case with buying most brands of trigger cables, the correct and best choice is ALWAYS the 5.5/2.1mm connector.? It will provide better performance over the long term, and will avoid confusion with 2.5mm connectors which don't have spring connectors, and are dangerous for use with QMX/QMX+.
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Stan KC7XE? |
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On Sun, Apr 6, 2025 at 11:48 PM, John Pokluda wrote:
Why on earth take the risk with an oversized barrel, even after Hans' otherwise comment?!Hans's comment is: 5.5 x 2.1 is correct.? my comment is: THIS?5.5 x 2.5mm?plug? on? works?with?no problem! Both are true you can change the plug if you want. 73 DE muhsin TA1MHS |
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On Sun, Apr 6, 2025 at 05:11 PM, Stan Dye wrote:
Stan
THIS 5.5 x 2.5mm?plug? on works with no problem! other people are using it with their PDs and QMXs on POTA activities. I tried to get an ?intermittent contact just for you, but I couldn't, sry. 73 DE muhsin TA1MHS |
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On Sun, Apr 6, 2025 at 05:03 AM, Muhsin TA1MHS wrote:
YES!?5.5 x 2.5mm?plug?works with meSome 5.5x2.5 plugs may work. But you inherit extra risk of intermittent power connection, which for some users has resulted in damage to their QMX internal power supply.?
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The QMX/QMX+ power input is designed for a 5.5x2.1 plug.
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Stan KC7XE? |
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5.5 x 2.1 is correct.? 73 Hans G0UPL On Sun, Apr 6, 2025, 13:03 Muhsin TA1MHS via <muhsin.dogrular=[email protected]> wrote:
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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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