Hi Zack, I have asked this question too and recently took a chance with a Black and Decker MAXX SST series power inverter. They have several different sizes and my daughter wanted one for her laptop in her car and found a deal on the internet under $20 each, if you buy two and with no shipping cost.
Mine may be too small for your application as it is rated for 1.74 amps at 115 VAC which seems very close to the maximum for the HP Laptop which has a rating of 1.7A at 100 to 240 VAC for the power supply and puts out only 3.5 A at 18.5 VDC. So I was a big concerned about overheating. As it turned out to worked quite well. This allows me to operate the lap top for mobile use or in the shack without AC power (I have an emergency power 85 amp hour AGM battery). The input rating on the unit says 12.8 VDC at 20 A which is 256 watts. The power output at 1.74 A @ 115 VAC is almost exactly 200 watts. Usually these devices are better than 80% efficient though so these numbers appear to be conservative. 200 / 256 = ~ 78%. I ran it for several hours and found no overheating or serious noise problems in any of the equipment. It is a modified sine wave as are most of the low cost devices of this type. Now for your larger laptop, you may need the next larger size to not push the limit. Even though your laptop draws about 120 watts (double my wife's laptop), assuming a similar 78% efficiency, it may work with a 200 watt size inverter, but it might be pushing it very hard. I am guessing that your laptop power supply with claim an input 115 VAC current close to 3 amps? Something else that is a concern is that using even a 200 watt inverter from cigarette lighter connections is not recommended if you are pushing it to the limit. Then they recommend direct battery connection. In fact, they include large batter clips to attach directly to the battery. Needless to say, you are not going to be able to use this when traveling. What I plan to do in any future vehicles is to have a heavy (10 gauge) wire running from the battery and ending in the passenger compartment with an Anderson Powerpole connector. The I can use one of those Red-Dee-2-Connect splitters to run ham equipment, computer inverter, etc. My wife has this now in her pickup truck which makes it very convenient to connect up several rigs. 73, Rick, KV9U Zack wrote: > Can anyone suggest a DC to AC inverter that is low in EMI? I have a > Flex-5000 rig that needs a laptop to function. I would like to use the > rig and laptop for WSJT hilltopping. > The laptop is an HP Pavilion zv6000 that requires 18.5v 6.5A. The > connector to the laptop has a strange 5 pin connector. I am not trying > to get 18.5v 6.5A from an inverter. Just looking for 120VAC to power > the PS that puts out 18.5v 6.5A for the laptop. > > Zack > N8FNR > > >
