Zombie Squad Amateur Radio Network: part 3 - Equipment

[Noven]

I am looking at power supplies, and I was wondering how big and powerful of a supply do I really need? I have a Yaesu FT-100D on my way, and I really do not understand which supply I should get.

On a side note, I am also putting together a power supply from an old ATX computer power supply, and once I hit up Ace Hardware, that will be done.

[American_Infidel]

RigPix database states that the current draw on TX is 22 amps.

http://www.rigpix.com/yaesu/ft100d.htm

So I'd be looking for something in the 25 amp and higher range. MFJ 4125, Astron RS-35a and SS-30 are all rated at 25 amps. The 4125 and the SS-30 are switching power supplies which are smaller and lighter than the RS-35a which has a big transformer and weighs over 20 lbs. I have both the MFJ 4125 and the Astron RS-35a. I bought the MFJ new and it worked about three months before it went out. MFJ replaced it under warranty and the new unit is still running along. I bought the Astron off of eBay for a very good price, but I literally searched everyday for a few months till I finally won one for the price I was willing to pay.
I use the Astron for my fixed station and the MFJ is going into a battery back-up project I am scrounging parts for.

[Noven]

Looking at my ATX power supply, I THINK it says that it outputs 18 amps at 12 volts. Will that suffice until I can get a more robust power supply?

[American_Infidel]

You'll have to turn down the radio power to say 40-50 watts but I don't know for sure. If it is like most radios, the power out/amps drawn is not linear meaning that if it pulls 22A on 100W TX, it will not pull 11A on 50W TX.

[Dah Di Dah]

You'll have to turn down the radio power to say 40-50 watts but I don't know for sure. If it is like most radios, the power out/amps drawn is not linear meaning that if it pulls 22A on 100W TX, it will not pull 11A on 50W TX.

A 100 watt transceiver only draws about 9 - 12 amps - depending upon if the fan is running or not and the model.

A 35 amp power supply is mininum requirement - since a 20 amp power supply will only supply about 12 amps of continous power - not enough for 100% duty cycle - needed for CW or digital modes.

Astron power supplies are Amateur Grade Equipment, communications grade equipment has a 100% duty cycle and also a larger termperature range which you can operate it under.

The Astron power supply is only duty rated to 32* F