apache-labs.com

I would like to purchase a switching power supply to use with my Anan 7000dle mk2. This is for my backup station that I only operate during the summer. My primary station is using a linear supply.

Thanks,
Ron
WB2RON

I forgot to mention that I am considering the Alinco DM-330MVT. Any comments good or bad?

Ron

My new fav power supply is the Samlex line. They are the only one I've found so far that do NOT ground the 12V common line to the chassis.
See my QRZ page for my campaign to get manufacturers to quit doing the common ground and similar USB shield grounding problems.
https://samlexamerica.com/product-categ ... -supplies/

I'll also suggest Samlex.

w9mdb wrote:My new fav power supply is the Samlex line. They are the only one I've found so far that do NOT ground the 12V common line to the chassis.
See my QRZ page for my campaign to get manufacturers to quit doing the common ground and similar USB shield grounding problems.

Mike,

Unknowingly, you likely have your power supply's negative terminal and chassis bonded regardless of any such connection at the power supply. Once the supply powers equipment where there's a bond between the equipment's negative lead and chassis, you have an unavoidable bond -- and some of those bonds are long loops that also include premise AC wiring ground wires.

Typically, a shack's supply is providing power for all kinds of things, including 12V station accessories. Almost all accessories bond the negative terminal to the chassis.

Because of this dilemma, I would rather not have a long terminal to chassis loop. As such, I first bond at the supply. If any anomaly develops, I'll then try isolating at the power supply and look for any improvement, especially with hum or RFI issues.

In the past and when trying to solve some difficult hum and buzz cases, I've used separate supplies for rig power and accessories where the rig's chassis is isolated from the negative 12V lead -- and nothing else on that power supply.

Paul, W9AC

Not unknowingly -- I've tested all my equipment and every piece has a grounding mistake.
All 12V common lines are grounded to chassis and all USB jacks have shield tied to pin 4. Yuck!!!

I'm fixing them by isolating where possible starting with the power supply. I have two Samlex power supplies to start with.
Main thing is to isolate the rig from everything else since the majority of the "noise" signal is going out the common line on the rig and the grounds. I've got an optical cable from the rig to my network switch to isolate the ethernet. I've got USB adapters which isolate the shield on most devices (ones where they don't need the shield connection to work). I've reduced the noise on the ground lines significantly with all this and no longer have any problems with USB devices disconnecting and I don't need any chokes any more. I do put chokes on the keyboard and mouse cables as they are just big antennas and have no ground of their own.

Daiwa SS-330W is clean

Could you please test your Daiwa SS-330W to see if the negative DC common line is grounded to chassis and the ground lug on the power connector?
You do need to disconnect all other lines first to check it properly. I'd like to add it to the list on my QRZ page.

Yes it is grounded.