[Elecraft] battery backup, etc. for QRO K2?

[Phil Kane]

On Wed, 11 Jul 2007 11:22:15 -0700 (PDT), Chris Kantarjiev wrote:

>What have other people set up along these lines? What website
>should I be visiting? Is the "super" powergate really worth
>double the price? :-)

  I run my multi-receiver / multi-transceiver station from a 100
  AH gel-cell float-charged by an allegedly regulated MFJ 45A
  switching supply through an isolation diode (one half of an
  automotive dual-battery isolator connected "backwards").

  The steady-state load approaches 7A with all receivers and
  transceivers in "squelched/receive" mode.  The battery bus
  (load) voltage is 13.4V which means that the battery is near
  the end of its life - it falls to 12.6V under load with the
  charger removed. I plan to replace it with a higher capacity
  battery bank by the end of the summer.

  I would rather set the bus voltage at the recommended 13.8 V
  float voltage. The only problem with this is getting the supply
  to maintain 14.6V. Right now it's at 14.2V and the isolator
  drop is the advertised 0.8V including the 0.2V drop through two
  shunts for measuring the battery and load currents.

  I hesitate to remove the isolation diode lest the supply
  voltage fall below the battery voltage for some reason and
  reverse current flows into the supply regulator.  That can
  happen when "adjusting" the variable voltage output and it
  destroyed a linear supply that I had many years ago.

  That's how I do it.

--
   73 de K2ASP - Phil Kane
   Elecraft K2/100   s/n 5402