12 to 24 volt conversion, the issue of cost

[Wilson Lamb]

No flames here, but a suggestion to be reasonable.  Some things may be 
beyond your budget, as many are beyond mine!  How much trouble is running 
some old junk radios worth?  You can hook up two batteries and run them for 
a while...maybe long enough!  A very few bucks spent building a modern radio 
or some time learning a digital mode  might bring you more rewards.  The PSK 
modes are almost painless and extremely effective.  I struggle to make 
myself put out the effort to keep up rather than look back.

Designing a DC-DC converter to deliver 10-30 amps at 24V is not an exercise 
for non engineers.  Hefty transistors and cores are needed, as well as 
sophisticated regulator circuits.  Sure, you can copy something, but even 
that requires some pretty good test equipment and, of course, buying the 
components that are modern enough to work well, like good FETs.  I have a 
little training and a lot of experience, some of which involved big 
transistors turning red hot, and I wouldn't try doing all the magnetics 
necessary to do this thing right!

My guess is that the cheap way out is an auxiliary battery big enough to 
give you an hour or two of fun, then be clipped across the vehicle system or 
recharged at home.  But you have rejected this idea, of course.  Do you have 
a generator?  How about building 24V supply big enough for the radios 
(easily done with cheap components) and running that on the generator?  You 
could make yourself look like a little comm outpost in the jungle...maybe 
put up some camo nets!

73,
Wilson, W4BOH
52 yr ham and still having fun


----- Original Message ----- 
From: "Michael Tauson" <wh7hg.hi at GMAIL.COM>
To: <BOATANCHORS at LISTS.TEMPE.GOV>
Sent: Thursday, October 08, 2009 10:36 AM
Subject: 12 to 24 volt conversion, the issue of cost


As the one who started this thread, I really like all the responses so
far and they've proven to me that many solutions do exist.  But darned
near every one has been something that has a price tag that I hope
someone else is willing to pick up because I sure as heck can't.  Let
me get this perfectly clear to everyone, I LIVE ON A VA PENSION AND
BARELY HAVE ENOUGH TO MANAGE WHAT I CAN DO NOW!  (Oh, and I'm not fond
of rice & beans as a constant diet.)  Please, folks, don't spend money
I simply don't have or try to rebudget that which I do but rather
think cheap.  Some of the "cheap & easy" solutions people have
directed me to are my food budget for no less than one month and
upwards of three - and that is at commissary & Wally World prices.

Only a few actually caught on to what I want to do - build (yes,
build.  You know, individual components and winding transformers and
soldering and all like that there stuff.) an inexpensive 12-to 24 volt
converter and learn about toroids at the same time.  How that got to
buying trucks is way beyond my comprehension but it tells me the
thread has gotten out of hand.  Go back to my original post to see
what I'm looking for ... and, as a hint, it has nothing to do with
adding batteries, adding alternators, or buying vehicles.

Let's see how quickly I get flamed for this.  I think I even know
who'll be the ones to cast the first grenades.

BEst regards,

Michael, WH7HG
-- 
http://www.nationalmssociety.org/chapters/NTH/index.aspx
http://wh7hg.blogspot.com/
http://kludges-other-blog.blogspot.com
Hiki Nô!

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