Astron SS 25M P/S Spikes on 10 Meters -- Cure??

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I've isolated spikes appearing every 70 or 80 kHz all across 10 meters. They come from my Astron SS 25M power supply. I shut all power in the house off and powered the rig with a 12 volt battery pack. Without load the Astron doesn't produce spikes, but with load it does. Please advise of any possible cures for this supply. If there aren't any, please advise of a clean supply; I assume the cleanest will be transformer based. Thanks. -- Jim W5HFS (6700, latest software, Windows 8.1)
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Jim Bryce W5HFS

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Posted 5 years ago

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Jim Gilliam

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Is this power supply a switching power supply? If so, that's your problem. They are notorious for spikes and noise.

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Jim Bryce W5HFS

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Jim, Yes, it is a switching supply. I'm familiar with their many problems and appreciate your observation. Tim at Flex has made a suggestion below that I'll try. Clearly the final solution is a transformer supply; however, it is handy to have a smaller and lighter supply for some temporary applications.
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Tim - W4TME, Customer Experience Manager

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Jim - there have been reports that lose screws inside the p/s can result in noise.  You may want to crack open the case and tighten all the screws you have access to.

Also, There are reports that the meter illumination in the SS-25M causing noise spikes.  This web page might be of some interest.
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Ed, K0KC

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It has been a few years, but I have two of these little supplies and was able to clean them up considerably by snipping the wires powering the bulbs or LEDs illuminating the meters. No guarantee that this will clear-up the 10 meter problem, but it would be worth a try as you could always replace them if they do not reduce the spurs.

Ed, K0KC
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Jim Bryce W5HFS

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Tim, Thanks so much. I'm planning on opening it up and checking around. The meter lights are something I would not have thought of. Thanks, and thanks for the URL reference.
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SS = Switching Supply   M= Metered

Get a stock of Mix-31 split beads etc as you may need to bypass the AC line or DC leads. 
I have a Yaesu charger for HT that puts out hash when the device is fully charged.
Went thru this exercise and found a lot of stuff in the house that causes hash.
If anyone is interested I'll give a summary. 
I found it handy to be up at 03:00AM when the RFI from outside the house was minimal.

Good Luck.

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Ray Andrews, K9DUR, Elmer

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I had heard of the Astron switchers being noisy. 

I recommend the Alinco DM-330MV switching power supply.  I personally have 3 of tem & one has been in nearly continuous use for over 10 years.  Also, our club has 3 in the club station.  Nary a peep out of any of them.

73, Ray, K9DUR

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Stan - VA7NF

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I found the DM-330 is also an EMI generator, especially at LF and BC.

A ground connection directly from the PS certainly helps.

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I have the new Alinco DM-330FX that is VERY quite even down on the LF and BC bands. 
It's BY FAR the quietest Switcher out of about every brand out there, the next one which isn't real bad on the HAM bands is the Samlex 30 Amp supply but it is noisy on the BC and LF bands.

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I don't know why the link says 300W. It is a 40lb chunk of iron that produces up to 60A linear. Sometimes it trips the mains circuit breaker when I switch it on (no soft-start). But, otherwise, has worked well for me.
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KY6LA - Howard, Elmer

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All Switching Supplies by their intrinsic design generate noise.  Some of the more expensive ones are equipped with tuning pots so you can tune the spurs outside of your receive bands.

BOTTOM LINE... Avoid a Switching Power Supply if you want a quiet station.
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Write a replyHello has all,  I have the same with my ASTRON SS 50A all the 70Hz   
also with my wife's vaporeto, here all the 17Hz  
I am going to try the solutions  
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George Molnar, KF2T, Elmer

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All good bits. Some things that can help -- 1) remove the case, make sure all metal to metal contacts are not painted over. A Dremel tool can help here. Check the ground lugs - in my  Astron,   the connection was extremely tenuous with the painted case. Reassemble with all the hardware tightened. 2) Twist your DC cable for self-shielding. 3) Single point station ground and all the excellent KY6LA advice you can muster!

Good luck!
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Jim Bryce W5HFS

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I opened the power supply and found it does not have any lights, so cutting their supply would not solve the problem as mentioned in some suggestions. I went through and tightened the machine screws everywhere. A couple were fairly loose. After I reassembled the supply the spikes were gone. I conclude the loose fasteners were the primary cause. I just now noticed some other spikes on other bands. These may be from sources other than the power supply, and they are much less bothersome and much weaker than the ones of my first concern. Thanks to everyone for suggestions. I'll post as I discover any additional problems and find additional solutions. -- Jim, W5HFS