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Power supply?

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Rt169Radio

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Hi folks,I am trying to find a power suppy that can power mobile 2-way radios,cb radios,and ham radios.I was looking at these three power supplys:

MFJ-4225MV Power Supply

Pyramid PS3 Power Supply PS-3

Samlex RPS-1204CPBT Power Supply RPS1204CPBT

Do these work by plugging into a wall outlet,then it powers up and then you can connect your radio? I do understand that the radio watt output has to do with it to,I would like a power supply that could handle a total of 60 watts output.Thanks
 

LtDoc

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Most radios will give you the typical current requirements in the manual (hope you have the manuals!). If you plan to power more than one radio at a time, then add their current requirements together to find the total current requirements. They can 'add up' fairly quickly.
Power supplies have two ratings, ICS and CCS. ICS means Intermittent Current Supply, or very short periods of time for that current level. CCS means Constant Current Suply, or what it'll do all day long. The biggy is that CCS rating, and unfortunately the most common rating given in advertisements is the ICS rating. That ICS rating is always lower than the CCS. That means that getting a larger than necessary power supply is a really good idea. As large as your wallet will allow (when your wallet screams real loud, the supply is probably adequate, maybe).
A power supply is one of those things where you almost never have too much, but is fairly easy to have not enough. Who knows what you may want to power later, you know?
- 'Doc
 

K9WG

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Adding to what LtDoc said, add up all the current requirements and then add 25% more. Your power supply should be rated at or above that.

I like Astron myself. I have had the 30 amp supply for going on 8 years now and no problems at all. In fact it seldom even kicks the cooling fan on. Only when I fun 100 watts of HELL or AFSK ;)
 

W9BU

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Most radios will give you the typical current requirements in the manual (hope you have the manuals!). If you plan to power more than one radio at a time, then add their current requirements together to find the total current requirements. They can 'add up' fairly quickly.
Bear in mind that at a home station you aren't likely to be transmitting with more than one radio at the same time. Most transceivers have two current ratings, receive and transmit. Make a list of the receive current ratings for all of your radios. Then find the one with the highest transmit rating. Remove that radio's receive rating from your list and add it's transmit rating. That will give you the maximum current your station is likely to require at any one time. Adding a 25% safety margin on top of that is a good idea and keeps you from over-taxing the power supply.
 

W2NJS

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The first power supply you listed is probably too big and fancy for your needs.
The other two are definitely too small for your needs.
Check the Astron website; they have a wide, wide range of units available and are very high quality.
 

majoco

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Stay away from the MFJ power supply - it says it's a switching regulator which will put out a lot of hash into your radios. The linear ones are too small to run all of those rigs together - I use one of those for each radio!
 

W9BU

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Poorly made switching power supplies can produce some RF noise. But you can't make a blanket statement that all switchers are bad.

I'm using an Astron SS-25 which is a switching PS made for radio communications. No hash.
 

K9WG

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Poorly made switching power supplies can produce some RF noise. But you can't make a blanket statement that all switchers are bad.

I'm using an Astron SS-25 which is a switching PS made for radio communications. No hash.
Same with my SS-30. I use it for my HF rig.
 

N4KVE

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Stay away from MFJ, & Pyramid. Many people have problems with them, although some people are happy with them. Samlex is good, but the head office is in Canada, so to get it fixed involves shipping to another country, customs, duties, etc. Astron is the best, & is available on the used market for a song. Just last year I picked up a SS30 used for $75, & it works great. That should run a 60 watt radio. GARY N4KVE
 

Rt169Radio

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Thanks for the info.Now I still don't know what power suppy to pick,would someone be kind enough as to go through this link and recommend a good power suppy for a total of 60 watts output,thanks.

Amateur Power Supplies
 

W9BU

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Power supplies are usually rated in terms of the volts and amps that they can supply. Receivers will have a relatively constant current draw rated in amps. Transmitters will draw a certain current in amps while producing a certain RF output in watts.

How much current in amps does your equipment draw?
 

W2NJS

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Put another way, basic ohms law tells you that 60 watts divided by 12 volts equals 5 Amps, but you can't "size" the supply by what the transmitter puts out, because it actually uses quite a bit more power than that in total. To be safe you should at least double the 5 Amps. to 10 Amps. for a 60-watt output transmitter. This is all basic stuff that's always covered in FCC licensing tests.
 

mm

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Stay away from any of the pyramid supplies because when they fail, and they typically do fail, they fail at a higher output voltage.

Also as others have mentioned stay away from MFJ just because they are poorly designed and incorrectly rated for proper current supply but worst of all the MFJ supplies are of extremely poor construction.

As an example, an MFJ supply may be listed at say 20 amps but this is with really light duty cycle operation.

The pyramids are most definitely the worst supply that you can buy, stay away from these things even if someone offers you a new one for free do not accept it if you like your radio equipment.

Pyramids have a nasty design flaw where they short open circuit and supply around 20 to 24 volts to the output, when these junk supplies short they do not shut down and they do not regulate properly like a good design should when subjected to even moderate levels of over current, the result is typically a blown or damaged radio due to over voltage and it's typically the power amplifier in your radio that is damaged.

Especially do not buy any pyramid supply that you see on e-bay, and also any flee-bay radios that are being listed by the same seller along with any model pyramid supply may have problems.

Stay with Astron and if you're into weak signal CW and SSB operation then try for one of the Astron Linear supplies, the Astron switchers have some low level spurious switcher noise problems that will effect weak signal SSB and CW work.



Mike
 

majoco

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the Astron switchers have some low level spurious switcher noise problems that will effect weak signal SSB and CW work.
Well, I'm glad someone agrees with me. We don't all listen to those big signals.
 

Rt169Radio

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I will probably get a Astron power supply,thanks everyone for the input.
 
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