Can anyone suggest a "quiet" solid state power supply what doesn't have any rf hash for use with a flex 6500 portable?

  • 1
  • Question
  • Updated 3 years ago
Looking for a quiet ss power supply thats not a noise generator.  These flex radios are showing me all the noise I have had but no longer able to ignore.  Somethings seen can not be unseen  Btw I am looking for a solid state instead of a linear power supply for portability.  I know one can't beat a linear ps for quietness

Thanks Lawrence
Photo of Lawrence Kellar KB5ZZB

Lawrence Kellar KB5ZZB

  • 187 Posts
  • 25 Reply Likes
  • happy...Love my two flexes

Posted 3 years ago

  • 1
Photo of KY6LA - Howard

KY6LA - Howard, Elmer

  • 3374 Posts
  • 1271 Reply Likes
By their very design all switching power supplies generate RF noise. Some of the better ones allow you to tune the switching frequency so that the noise is outside the ham bands.

I can't recommend specific models as I long ago changed out all my switching supplies for linear ones
Photo of Ken - NM9P

Ken - NM9P, Elmer

  • 3759 Posts
  • 1145 Reply Likes
I am having good luck with the Alinco Dm330. So far I have not been able to detect any hash or PS generated carriers except for way below the AM Broadcast band.

As I begin applying Howard's techniques for quieting the station even further, and the power company continues its work, I am considering moving to an AGM battery and supply isolator. Detected noise will help make that final determination.
Photo of Jim Jerzycke

Jim Jerzycke

  • 89 Posts
  • 19 Reply Likes
+1 on the Alinco.

I used to use an Astron SS-35, but it started generating noise, so I shelved it.

Photo of philip.theis

philip.theis, Elmer

  • 111 Posts
  • 19 Reply Likes
a battery is a great choice for that scenario (when portable)
Photo of David


  • 279 Posts
  • 47 Reply Likes
Flex radio sells the Astron ss-25 so they should be able to comment on it. I have been told that it runs quiet only switching the fan on when needed. RF wise it is supposed to be "clean".
Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1486 Posts
  • 524 Reply Likes
Pretty good results with the Astron supplies. I did sand off the paint at metal to metal points to make them better shielded. Same at grounding lugs inside.

PS - I did ultimately go linear, but more as a response to my neurotic obsession with every last dB of noise. The Astron 35A Switcher was just fine.

I blame Howard for my toroid and grounding therapy. <g>
Photo of Tim - W4TME

Tim - W4TME, Customer Experience Manager

  • 8466 Posts
  • 3162 Reply Likes
If you do as George describes and re-tighten all the screws inside the chassis every few years, the Astron SS supplies are fairly quiet.   However, I do only use linear supplies in my shack.
Photo of NX6D Dave

NX6D Dave

  • 259 Posts
  • 63 Reply Likes
I'm using a 32amp Alinco. It appears to be very quiet, rf and sound. It has a handy 13.8 volt . So far I've not seen a birdie that I can blame on the PS.
Photo of Dave - W6OVP

Dave - W6OVP

  • 206 Posts
  • 69 Reply Likes
I bought an MFJ-4230MVP 30A switching for the FLEX 6300 a year ago. It is NOT made by MFJ but they relabel and carry it. Liked it so much I bought 2 more for other rigs. -Dave
Photo of Ray Andrews, K9DUR

Ray Andrews, K9DUR, Elmer

  • 227 Posts
  • 52 Reply Likes
I heartily recommend the Alinco DM-330 series. I have, with the oldest being over 10 years old. No RF hash detectable.
73, Ray, K9DUR
Photo of WX7Y


  • 407 Posts
  • 71 Reply Likes
I also recommend the Alinco DM-330, my particular one here is the DM-330FX, It has a noise offset adjustment just in case but I have not had to use it. 
Bret, WX7Y
Photo of Lee

Lee, Elmer

  • 672 Posts
  • 281 Reply Likes
I have 3 samlex 1223's running in my shack very quiet
Photo of Barry-W4TGA


  • 7 Posts
  • 1 Reply Like
I want to also strongly recommend the Alinco DM-330MV.  I have used them for years and they have become my first choice for home and away.
Barry - W4TGA
Photo of Lawrence Kellar KB5ZZB

Lawrence Kellar KB5ZZB

  • 187 Posts
  • 25 Reply Likes
Thanks all.  i will look at the Alinco.  
Photo of kr4k


  • 72 Posts
  • 10 Reply Likes
Use Astron SS-50 for each rig. Always have placed RF choke on power lead just as the cables leave the power supply. Powerful and lightweight. use it for equipment making sensitive noise measurements.
Photo of Stan - VA7NF

Stan - VA7NF

  • 385 Posts
  • 82 Reply Likes

Also use a DM-330-MV which created significant noise at 80M and below, however

Open it up and do as George suggested.  Grounding the chassis (small external binding screw) made a significant difference.  Also use it to charge/maintain a battery that runs the 6700.

Photo of George Molnar, KF2T

George Molnar, KF2T, Elmer

  • 1486 Posts
  • 524 Reply Likes
Looks like a lot of us have batteries running our rigs. With something like a PWRGate in line, it's nice peace of mind when running remote and does help with noise.
Photo of K0UNX


  • 107 Posts
  • 30 Reply Likes
I also highly recommend the Alinco DM330MV.  It has a knob to "tune out" any birdies, but I've watched the waterfall and panadapter, and don't see any birdies at all while cranking that knob.  I *DO* have some regular birdies that come from my CABLE INTERNET CONNECTION.