Yes, they run whenever the supply is turned on.

I wish they would default to slow, then speed up as needed, but they 
don't.

The fan on the larger supply isn't nearly as noisy as the one on the 
smaller unit.

I suspect the smaller fan is turning faster, but I don't know that.

I normally only have the larger supply going.

The 25 amp supply was bought to be part of a "radio in a box" that I 
am putting together, so I don't use it every day, at least not right 
now.


I'll write more about the Radio in a Box later.

----- Original Message ----- 
From: "Butch Bussen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Wednesday, March 20, 2013 9:20 PM
Subject: Re: Power Supplies


Do the fans on your mfj supplies run all the time as mine does?  I 
leave
my equipment on 24 7 and I hate a fan that runs all the time.
73
Butch
WA0VJR
Node 3148
Wallace, ks.


On Wed, 20
Mar 2013, Mike Duke, K5XU wrote:

> Just for comparison, before you drop money, take a look at the MFJ
> 4125, 4225, or 4245 supplies.
>
> Having just bought a 4125 about 3 weeks ago, I can tell you that 
> this
> 25 amp supply is $84.95, and perhaps a little less in some places.
>
> It is quiet in the spectrum, but the fan does make more noise than 
> the
> one in my 4245, which is a 45 amp model.
>
> The 4125 is a basic model that has no meters. Because of that, it is
> about half the height of the 4225, which is the 25 amp metered 
> model.
>
> The one I bought uses the 5 way binding posts, but an Anderson Power
> Pole model is also available for about $10 more.
>
> The 4225 and 4245 both have front panel meters, plus a cigarette
> lighter socket in addition to the other connectors. They are 25 and 
> 45
> amps respectively.
>
> All of them also have spring loaded speaker type connectors for low
> current applications. These connectors are rated at a maximum of 5
> amps.
>
> There is also a 15 amp MFJ model for about $60.
>
> As someone said, that 15 amp model will run the TMV71 just fine at
> full power, but it won't leave you any wiggle room.
>
> A 25 amp supply should run a 100 watt HF rig full tilt on anything
> other than a continuous duty mode like FM or RTTY.
>
> A 45 amp model will very likely handle anything most of us would 
> ever
> throw at it other than a solid state amplifier.
>
>
>
>
> Mike Duke, K5XU
> American Council of Blind Radio Amateurs
>
>