[Elecraft] Switching PS for travel with K2/100

[Don Brown]

Hi

I have a MFJ-4125 and a MFJ-4225-MV although you can hear the fans =
running I would not say they are "hideously noisy" nowhere near as loud =
as a typical computer power supply fan. The 4225_MV is a little louder =
because the fan mounts on the inside left side rather the back as on the =
4125. The 4125 fan is barely audible. I also have a MFJ-4245-MV 45 amp =
power supply. It's fan is louder but still not louder than most desktop =
computer fans. All of these supplies are very RF quiet. The reason is =
they use a resonate sine wave type of switching circuit rather than a =
square wave switching circuit used in many computer supplies. Because =
the transformer and rectifiers are driven with a ultrasonic sine wave =
the harmonics are inherently low and it is much easier to filter the =
output into a very clean DC. They also come with a schematic and can be =
adjusted up to 15 volts so they can charge the K2 internal battery. =
Something else interesting about the 4125 is if you remove the plastic =
feet the supply will fit into an EC-2 Elecraft case that matches the K2. =
You could add a K2 speaker to the front of the EC-2 and perhaps a =
voltmeter or ampmeter and have a nice station accessory for your K2

Don Brown
KD5NDB=20
  ----- Original Message -----=20
  From: Buddy Brannan=20
  To: elecraft@mailman.qth.net=20
  Sent: Friday, August 01, 2003 8:28 AM
  Subject: Re: [Elecraft] Switching PS for travel with K2/100


  Hi John, et al.:

  You'll have to let us know how your Samlex goes. I've heard that the =
Samlex has lots of noise around 80 meters, but then I've heard it's =
absolutely fantastic. Conversely, I've heard the MFJ supplies are RF =
quiet but have a hideously noisy fan. Anyone wanna comment?=20
  --=20


--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---