¿ªÔÆÌåÓý

ctrl + shift + ? for shortcuts
© 2025 Groups.io
  1. QRPLabs
  2. Topics

QMX+

Marty Van De Ven
 

Just received the kit and am building it for 9 volts.? Any problems running it at 10.5 volts or so?? See many post about not going over 12 volts for that build but nothing about 9 volts. Can't wait to use this on the air.

Marty, K8MV
 

Marty, If you built it for 9v, then you should run it at 9v. It might take a higher voltage, but I? run mine at less than the voltage I built for, and have never blown a final or burned anything up.? I use small buck converters to set the voltage a little lower. This also helps minimize the RF coming back into the shack. I have fewer issues overall that way.
--
73, Dan - W2DLC
 

Marty;

I have run my 9V QMX on 10.5V, when running 8 fully charged NiMH cells, and the battery voltage would sag to ~9.3V on transmit while outputting ~5W RF CW.

However, even with the voltage sag, I would be very cautious about running it into anything other than a 50 ohm load. I am now using a PD powerbank with a 9V trigger cable, so the TX never sees anything above 9.1V. It runs for days on the powerbank...
72 de Russ va3rr
Marty Van De Ven
 

Thanks Russ, what PD powerbank? and 9volt trigger cable are you using?

Marty, K8MV

On 7/26/2024 8:51 AM, va3rr via groups.io wrote:
Marty;

I have run my 9V QMX on 10.5V, when running 8 fully charged NiMH cells, and the battery voltage would sag to ~9.3V on transmit while outputting ~5W RF CW.

However, even with the voltage sag, I would be very cautious about running it into anything other than a 50 ohm load. I am now using a PD powerbank with a 9V trigger cable, so the TX never sees anything above 9.1V. It runs for days on the powerbank...
72 de Russ va3rr
 

The trigger cable is a "DSD Tech MagicConn" 9v trigger cable and the powerbank is an Iniu 22.5W with USB-C PD. Both purchased on Prime day.

Do a search on this group for "trigger" and you should see many recommendations.
.rr
Marty Van De Ven
 

Thanks Russ, all is ordered on Prime

Marty

On 7/26/2024 12:07 PM, va3rr via groups.io wrote:
The trigger cable is a "DSD Tech MagicConn" 9v trigger cable and the powerbank is an Iniu 22.5W with USB-C PD. Both purchased on Prime day.

Do a search on this group for "trigger" and you should see many recommendations.
.rr
 

Thanks for the hint on the "Iniu 22.5W powerbank with USB-C PD".
At least in Germany you can buy it with a 63% discount on list price till July 29 at Amazon. Just ordered one.
Per manual, the powerbank can deliver 1.5A @ 12V or 2.22A @ 9V with an appropriate USB C trigger cable.?
--

73, DB2OO -Joerg

1 - 7 of 7