View Full Version : Terrible interference problem...
N6UGY
11-09-2006, 08:12 PM
Recently I purchased a new power supply for my HP Pavillion 310N, and was sold an "A POWER" brand supply. It was 320 watts compared to the origional 180 watt supply. Anyway, that night, I noticed when I was on the 80 meter Ham band (just below 4 MHZ) that the supply was emitting a very storng signal all across that band. Turns out that it's everywhere I checked, on all the Ham Bands, and CB too !!! Turns out that the "A Power" units are not FCC Rated !!! More chinese crap !!! lol
I called the dude at "Micro Sat" where I purchased it here in Red Bluff, and he's looking into the FCC Rating of supplies, so he can get me a quality unit. Looks like i'll be changing out that power supply again.... Rats !!!
KI4QFY
11-10-2006, 02:21 AM
Astron. http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif
N6UGY
11-10-2006, 09:04 PM
Not the radio power supply, the power supply in the computer. The new one I installed emitts a carrier all over the ham bands. Micra Sat (where I purchased the supply) has ordered a better one for me, we'll see...
All I know is that the origional power supply in the computer didn't do that. Hopefully the new one he's ordering me won't do it ...
KC7UP
11-11-2006, 02:42 AM
Two years ago when I had this computer made locally I found out it emitted rf all over the bands. I told the builder initially I want all parts to meet Part B specs. I took the computer back and asked him to check the power supply for rf.. He didn't know how. http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif
So I brought out my little dc am/fm radio and show him the noise and made them hunt around until they found one that met FCC spec. Been happy since then.
Curt
N6UGY
11-11-2006, 06:34 PM
Good idea... Now I know why every time I drive past that place, I get a strong carrier on my mobile rig. lol With any luck, the one he's getting me will be of good quality, and not do that. Dennis
kc8adu
11-29-2006, 12:38 PM
that brand and about a dozen others are the same unit made by powmax.
pure junk and possibly dangerous to have plugged in.
get a fortron,pc power and cooling,or even a high end antec.
i bet you have a micro atx unit so choices are limited.
i work in componant level repair and usually just repair the original.
yours is likely an astec or delta.
most are easy to repair unless they swallowed a bolt of lightning.
N6UGY
11-29-2006, 04:35 PM
The factory supply was a Bestech...
kc8adu
12-05-2006, 10:32 AM
eewwww.
you are lucky it didnt kill the motherboard.
ask any emachines owner.
drop that psu in the circular file.
N6UGY
12-05-2006, 05:03 PM
This time he gave me a 420 watt unit, and it does the same thing. I don't need the extra watts, I need good filtering. lol The stock 180 watt bestech unit never made RF like these a A Power units. Yep, he gave ma another "A power" supply. Now im getting a little annoyed...
ka5piu
12-10-2006, 03:33 PM
Hello.
You can find clean supplies, it is just a matter of looking.
I bought a PC power and cooling supply and have been very pleased.
http://www.pcpowercooling.com/home/
Note that on the silencer series that is a copper plated housing.
Super quiet in RF and in sound, runs totally cool.
N6UGY
12-10-2006, 05:35 PM
Thanks !!! I'll give em a call tomorrow... The guy here in town keep giving me "A Power" crap supplies. lol He actually suggested there's something wrong with my ham radio. Yeah, and it went bad when I installed the new power supply... lol
WA9SVD
12-11-2006, 06:43 AM
Actually, most of the supplies are designed fairly well. The PROBLEM is they aren't built that way!
If you open them up, you can see the locations for the bypass capacitors, chokes, etc.; all missing, to cut costs in alow-profit margin market. But with no filtering, there's no RFI suppression.
As suggested, an ANTEC or "PC Power and Cooling" supply will most likely solve your problem. Perhaps changing to another store would help?
Quote[/b] (N6UGY @ Nov. 09 2006,16:12)]Turns out that the "A Power" units are not FCC Rated !!! More chinese crap !!! lol
I called the dude at "Micro Sat" where I purchased it here in Red Bluff, and he's looking into the FCC Rating of supplies, so he can get me a quality unit.
You can only tell by the FCC mark if a PS meets EMI standards if it is made by one of more reputable manufacturers; the US has been flooded with (largely) Chinese electrical and electronic equipment with counterfeit FCC (http://www.fcc.gov/oet/ea/labels.html) and UL (http://www.themanufacturer.com/us/detail.html?contents_id=4859) marks, and there seems no effective way to stop it.
You might ask the seller for a UL listing number (for safety). You can go to the UL's site (or ETL's, or any other nationally recognized test lab whose mark it bears certifying it is safe) to see if UL really did list it. "Made with [NAME]" Approved parts" doesn't cut it for safety, either.
Cortland
KA5S
N6UGY
12-11-2006, 06:24 PM
Thank You, I just called him and requested a unit from PC Power and Cooling... Ha !!! He never heard of them. Geeeeeeeeze....
ke5fry
12-12-2006, 09:49 PM
This sounds familiar. When I got my general and bought my first transciever, i was getting an S8 noise level on nearly every band and finally traced it down to my data collection computer power supply. A replacement fixed it. I tried filtering it out with ferrite on the power cord and it helped but not enough.
N6UGY
12-12-2006, 10:34 PM
Yesterday I told him if he couldn't get me a PC Power and Cooling supply, I would order it myself. I don't mind him making a few bucks, but I don't want to keep changing out the power supply.
Quote[/b] (KC7UP @ Nov. 10 2006,22:42)]Two years ago when I had this computer made locally I found out it emitted rf all over the bands. I told the builder initially I want all parts to meet Part B specs. I took the computer back and asked him to check the power supply for rf.. He didn't know how. http://www.qrz.com/iB_html/non-cgi/emoticons/rock.gif
So I brought out my little dc am/fm radio and show him the noise and made them hunt around until they found one that met FCC spec. Been happy since then.
I did computer EMI for a bit over 13 years. I'm still in EMC, but moved from computers to telecom, to medical and to aerospace.
It is possible to build an FCC Class-B-compliant computer from FCC tested and approved chassis’, power supplies, mother boards and peripherals. Not necessarily easy, but possible. The real problem comes when Joe Storefront buys whatever cheap boards he can get and throws them into whatever cheap chassis he can find, with whatever cheap power supplies. Even if they were really tested to Class B, once upon a time (and quite a few are not) putting motherboards with different kinds of peripherals, chassis’ and power supplies than originally tested with means the results are unlikely to actually meet Class B limits.
And the lack of concern most discount manufacturers exhibit for FCC compliance is matched only by the lack of concern some have for safety.
It is sometimes possible to install a canned EMI filter in place of the IEC connector in a computer power supplies. Sometimes the PS board is even silk-screened and drilled for one, which has been deleted to save money. Switching power supply design takes a certain expertise; I work with a bunch of PS designers and good ones can make a quiet power supply with two chokes and a disk ceramic for a filter. The cookbook, copy-cat designers… you will NEED that canned filter.
Or buy a really safe, really quiet product made by a firm that cares about quality.
Cortland
KA5S