|Stable high-amperage power, but not radio friendly
||Time Owned: 0 to 3 months.
|I know I'm slitting my own throat by writing a poor review for this power supply, but I am ready to sell it and have only had it a few weeks! I bought it to power a new 500 watt R.F. Electronics Skywalker Amplifier that I built from a kit I bought a couple of years ago- it took me this long to get motivated to complete building the kit. I began searching for a power supply before kit completion because it would be needed for testing and adjustment. I was just about to buy an Astron RS-70, but then noticed that it's rated at about 55 watts continuous, not 70 amps! I found the IOTA DLS-75 for sale used on either E-ham or QRZ (don't remember) and did some minor research on it before committing to buying it. The seller said it was almost brand new, but I guess he needed the money for something else. I talked to the folks at IOTA because I was concerned about the voltage overshooting then falling back down. Lee Martin at R.F. Electronics advised that you had to be careful not to exceed 18 volts or you would risk blasting the power transistors! The person at IOTA eased my fears telling me that the voltage regulation circuit that they use ramps UP to the voltage and would not overshoot. So I went for it (the DLS-75)! It arrived in pristine condition, looking like it had never been used! I used it for all amp testing and tuning, and it worked just perfect! Then when the amp kit was completed, I moved the amp and power supply into my shack. I went to 75M and got some excellent signal reports. My wattmeter registered full output, and I never heard the power supply hum or "squat" at all even at full output of the amp. I moved to 14.300 on 20M, and noticed that the noise level was very high that day. I didn't think twice about it- I just continued operating. I moved some wires around while situating the amp and power supply to their permanent positions, and accidentally unplugged power to the amp. At the same time, the noise disappeared! I plugged and unplugged the power supply a few times to verify that it was the culprit of all my 20M noise, and sure enough- every time I plugged it in, the noise would come back- and unplugged, the noise level dropped from S-7 to S-2. That much noise would cover up a weak station- so, anybody want to swap an Astron RS-70 linear supply for a DLS-75 switcher? Or does anybody have a method to move the hash to another frequency besides 14.300?|