| Author |
Message |
    
Bridge_man
Junior Member
Username: Bridge_man
Post Number: 10
Registered: 3-2006
| | Posted on Saturday, August 19, 2006 - 3:54 pm: | 
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will a 40 amp mfj switching pwr supply work as well as a standard mfj 40 amp pwr supply to run a moble amp as a base amp? |
Moonraker
Intermediate Member
Username: Moonraker
Post Number: 243
Registered: 3-2005
| | Posted on Sunday, August 20, 2006 - 12:32 pm: |
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It's not quite enough to run a Texas star 500, would probably run a Texas Star 400. Anything smaller will work fine. |
Tech833
Moderator
Username: Tech833
Post Number: 1433
Registered: 8-2002
| | Posted on Monday, August 21, 2006 - 8:23 am: |
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Switching supplies work very well, until they have a problem... Then, they tend to go hard to one rail (usually high) and blow up anything connected to them. Also, RF hash is a concern. |
Chad
Senior Member
Username: Chad
Post Number: 1040
Registered: 11-2004
| | Posted on Monday, August 21, 2006 - 9:20 am: |
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I have also seen them to be sensitive to RF. Any tightly regulated supply using oodles of feedback can be driven nuts with RF. A few turns around s ferrite of the DC output and proper rounding solves this. As 833 says, they can make a bunch of nasty emission too, they operate like an inverter for a car, if you have any dealings with those...... yeesh!
Al in all though, when properly implemented, they are great! They weigh nothing, are very efficient (not much heat, and can be used in close proximity to things like computer monitors, TV's, Scopes, etc....
Chad |
Johnbrowning
New member
Username: Johnbrowning
Post Number: 9
Registered: 9-2006
| | Posted on Sunday, September 17, 2006 - 3:19 pm: |
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I have a Samlex 1223 23 AMP RMS switching power supply. I have no birdies at all on 10m or 11m bands. It weights 3.5 pounds and is the size of a cigar box.It came with a 3 year warranty and cost me $89. I think that Diamond brand from RF Parts rated better in CQ magazine then the MFJ 40 amp power supply. Yaseu and Icom make some sweet switching power supplies. Some of them allow you to tune the freq. where the birdies appear.
I can only speak to my little smalex but I have had to make an indoor ground plan from sheet metal and a magnet mount. This antena is only 4 feet from the radio and the radio easily swings to 65watts.The lawn mower hit my coax where it goes into the house and cut it so I can not use my outdoor ground plan. I have not seen any RF problems. I would imagine that 400-500 watts would not be much of a problem unless your ground plan is right next to or on top of the house.
I almost forgot my little 23amp power supply only draws 3amps at 120 volts at peak output. It is very effcient and if I want to travel I do not have to start lifting weights so I can carry my power supply. |
