MFJ-4225MV 25 Amp switching power supply - any opinions?
Kishore Sai Vejju
Hi,
I am considering buying the MFJ-4225MV 25 Amp switching
PS to be used with my HF transciever. Has anybody had
any experiences with this model?
Tnx.
73, Kishore, KC8FNA
Kk4bh
Kishore,
I just purchased a MFJ-4035MV power supply. I know this is not the same model
you're interested in but thought I would tell you a little about it since it is
very similar.
I use it to power my IC-706MKII and it works very well. Excellant regulation.
The only negative comment I have with it is the fan noise. If the fan circuitry
is the same in both models you may find it a little annoying. The fan speed is
a function of the amount of load on the supply. The more current you pull, the
faster the fan runs. There is a decay time of about 2 minutes after the current
being drawn stops. The fan will slowly "wind down" and eventually stop.
If I had it to do over again I would have purchased a Astron. They don't use
fans in their supplies, at least in their linear models. I had considered
exchanging mine, but it would have cost too much taking into account shipping
and restocking fees.
Hope this helps.
73's
Ken
KK4BH
ACI6
One more thing - If you plan to repair it yourself (provided it fails!) and you
are not experienced in repairing switching supplies, I think that you should
try to find a linear supply that will meet your needs.
The typical switching supply has a significantly higher component count that a
comparable linear unit and the linear supply should be much easier to
troubleshoot. I just repaired an Astron VS-35M that had been damaged by a
(lightning?) surge. I would not have even attempted to repair a switching
supply with similar problems.
The Icom 251A and 551A have switching supplies and I nearly went nuts several
years ago trying to fix one of those supplies that had been damaged by
lightning. Solution? Sent it to Icom. About a dozen replaced components and
$85.00 later it was working again.
There are advantages to having a switching supply - size, weight, first cost
(in some cases), but I just think the linear supplies are more straightforward
and, thus, easier to understand, etc. Besides, those switching supplies have
almost no scrap value at all. :-)
Regards,
Bill
Tom C. Brown, Jr.
Good points, Bill.
Fixing a switching power supply can definitely be a good mental exercise!
:-)
I have found two items to be indispensable when working on one: 1) a good
manual 2) a dual trace storage scope with a very high chopping rate.
73, Tom AE5I
ACI6 wrote in message <199804182034...@ladder03.news.aol.com>...
>One more thing - If you plan to repair it yourself (provided it fails!) and
you
>. . . .