[Amps] MFJ products

[Jim Thomson]

##  You forgot to tell us that it was a 40 A   13.8 vdc, switching type power supply !  
Found it on U tube, where the vdc pegged past 16 vdc.  Another fellow had his
way over 45 vdc...and fried his yaesu.    The u tube fellow says his  did not have
any over voltage protection built into it !   Since his was under warranty, MFJ will
repair it..... but not the very expensive yaesu xcvr. 

##  Fuses on radios  will only protect against excess current, not excess voltage.   Your
surge protector on the input of the 120 vac.. feeding the MFJ switching supply, will  not help at all. 
The issue is the lack of over voltage protection in the mfj switching supply, and what ever caused 
it to crank out excess  vdc in the 1st place... frying everything connected to it. 

##  Either   replace with a better quality switcher from a different manufacturer, or  use
an analog supply, like a  50 A  CCS astron. 

##  way too many issues with the MFJ-4245  switcher imo.  if the supply bows up, who cares... but when the
same supply  blows up  a bunch of expensive gear connected to it, then its a serious issue.  

Jim   VE7RF



 

From: Shon Edwards 
Sent: Sunday, December 03, 2017 8:42 PM
To: Jim Thomson ; Amplifier Reflector 
Subject: Re: [Amps] MFJ products

I know this isn't really an amp question, but I checked my email for mfj-4245mv and found this one.  Last week, the current just took off.  Fried a couple radios whose fuses didn't work.  Also my surge protector didn't stop it from frying my radios.  Any idea what caused this or how to fix it? 

Thanks!

de Shon, K6QT

Shon R. Edwards, MA, AG (Czech Republic)

Amateur call:  K6QT
1039 N 2575 W
Layton, UT, 84041-7709
USA
Home phone:  (801) 444-3445
E-mail:  sre.1966 at gmail.com


or

Shon Edwards
715 Strawberry Creek Private Rd.
Bedford, WY 83112
Cell:  (307) 248-2104

On Tue, Sep 11, 2012 at 8:22 AM, Jim Thomson <jim.thom at telus.net> wrote:

  Date: Tue, 11 Sep 2012 10:26:27 +0200
  From: "Peter Frenning [OZ1PIF]" <peter at frenning.dk>

  Subject: Re: [Amps] MFJ products


  My 5 cents worth:
  I own and use several pieces of MFJ equipment, much of it has been in
  daily use for more than 10years:
  a MFJ-4245MV SMPS, no RF-hash, and has performed nearly 24/ 7 for
  more than 10years
  a MFJ-259B antenna analyzer, without a doubt the most useful tool
  in my toolbox
  I know there are better/more accurate/higher quality analyzers
  available now - at vastly higher prices!
  this one has been in use for more than 10 years in my shack and
  in the field, and when I broke it
  (my own fault - reverse polarity) MFJ was very helpful with
  repair suggestions
  I owned a MFJ-969 tuner for several years - did exactly what it was
  supposed to do at a very reasonable price
  Various power meters an dummy loads - again they have been
  performing exactly as expected.

  To conclude: yes corners have been cut here and there, but at the prices
  asked you get fair usefulness and many times equipment which few of us
  could afford without MFJ supplying it.

  --
  Vy 73 de OZ1PIF/5Q2M, Peter

  ##  You obviously have not tried one of their SS HF linear amps..like the
  AL-600  or AL-1300.   I defy anybody to get one to run full bore for 5 years
  straight.

  Jim  VE7RF.


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