May 2002 QST had the computer power supply conversion article QST switching power supply product reviews are July 2006, January 2000, and Sept 2000
John Lock kf0m at arrl.net > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] Behalf Of Eric Lemmon > Sent: Sunday, August 03, 2008 10:10 PM > To: [email protected] > Subject: RE: [Repeater-Builder] Power Supply from a PC. Slightly OT > > > John, > > What issue of QST carried the article about converting a PC power supply? > > 73, Eric Lemmon WB6FLY > > > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] On Behalf Of kf0m > Sent: Sunday, August 03, 2008 7:41 PM > To: [email protected] > Subject: RE: [Repeater-Builder] Power Supply from a PC. Slightly OT > > I did a computer supply conversion here. the one I did was a > 150W supply so > only good for about 10A. I followed the QST article for the conversion. > This one had a pot for adjusting the voltage. I had to change > one resistor > value to get 13.8 VDC out. The output wave form looked like the early > commercial switching power supplies tested by QST. Those showed some RF > noise in the QST tests. > > I added a toroid with several turns on it, a big electrolytic > cap, a .01uF, > and a .001uF to the output. After that, the waveform on the "o" scope > looked like the 2nd round of switching supply reviews in QST. > Those showed > much less RF noise. > > Unfortunately I didn't have a spec ana. to check it but it hasn't caused > any RF problems for the low power repeater that it has been > running for the > last 6 months.. > > > John Lock > kf0m at arrl.net > > -----Original Message----- > From: [email protected] > [mailto:[EMAIL PROTECTED] Behalf Of Gmail - Kevin, > Natalia, Stacey & Rochelle > Sent: Sunday, August 03, 2008 11:05 AM > To: [email protected] > Subject: [Repeater-Builder] Power Supply from a PC. Slightly OT > > > Hi All, > > This request is slightly OT but still for Amateur and possible > Repeater use. > I read an article about using a PC power supply as a 12 and 5 volt/ > high amp atable power supply for the bench. > Looking over the specs it looks good for 12v at 19A and 5v at over > 30A. Was interested and due to the size of the PC power supply takes up a > lot less room on the bench then my standard Ham power unit. > > Before I go and use one of these (Have a couple of spares), I would > like to know if anyone has already tried this, and if so what problems has > it caused? Being a switch-mode is it very noisy on HF or even the upper > bands? > > Thanks > Kevin > > > ------------------------------------ > > > > Yahoo! Groups Links > > > >
