Re: 42 volts and QRP ?


From: Mike Yetsko (
Date: Fri Nov 30 2001 - 12:55:28 CST

Actually, I think there are two groups pushing right now. One for a
24/28 volt standard, and I think that's Audi and some others. And a
48 volt (I think) standard, with Daimler Chrysler and maybe some
other US groups.

Thing is, it would make car electronics simpler, lighter, and more
efficient. Car audio systems would benefit immediately.

Top compare this with the 6v to 12v jump of about 40-50 years ago
isn't really valid. Oh, the manufacturers are spouting the same
reasons as before, but now they have more technical backing for
the change.

On the down side though, there was a very limited user installed
base for car systems back then. What plugged into cars? There
was a limited number of radio setups, but they were comparatively
rare. And aftermarket audio, while it did exist (there was even a
turntable you could get back then) was very limited. About the
biggest market impact for devices back then was hand held
spotlights that plugged into the cigar lighter.

Nowadays there are literally thousands of 'plug in' devices. To the
point most manufactures don't even call it a cigar lighter any more,
it's an accessory outlet. And they put more than one in a vehicle.
And put them where there are no ashtrays, like by the rear door of
the Dodge Caravans (for super-light duty compressors to blow up
mattresses and beach toys, and yes, even real tire compressors).

I don't think the issue of 12v in a car and the impact on consumers
has been fully defined by the manufacturers from what I've read.
And I've read absolutely ZERO on high current applications. The
stuff that's equivalent of mandating a 'battery connection' for things
like 100W Icoms.


----- Original Message -----
From: "Charles Olson" <>
To: "Low Power Amateur Radio Discussion" <qrp-l@Lehigh.EDU>
Sent: Friday, November 30, 2001 1:15 PM
Subject: 42 volts and QRP ?

> I keep reading in the electronics trade press that carmakers are
> considering the increase of the car battery from it's present 12V to
(and I
> may have the details wrong) 42 volts! This increase is supposed to
> easier application of electronics and electrics (solenoids/motors) in
> braking, engine control and other areas.
> I'm wondering how this will affect ham radio and in particular, QRP ?
> Nearly all HF rigs on the market are designed to work directly from
> even though few actually spend much time in an automobile, so if the
> market increases battery voltage to 42V, will the ham radio
> follow ?
> The advantages of a higher car battery voltage for QRO are many,
> requirements can be lessened, MOSFET output transistors work better at
> higher voltages, in fact those solid state kilowatt amps will
certainly make
> a comeback.
> But are there any advantages for QRP? Maybe a slight increase in
> dynamic range by increasing the "headroom" of preamplifiers ?
> What are the disadvantages of 42V supply voltage for QRP ? Adding a
> LED pilot light to a nominal 42V supply might "cost" nearly a watt,
will our
> favorite junkbox resistors need to increase from 1/4 watt to 1 watt ?
> I assume there will be a long time of transition where the auto
> will fully support the old 12V standard - how long did it take to go
from 6V
> to 12V ? I'm think that we will all come to know and love switching
> technology that can be used to "pump down" the voltage efficiently
(but will
> it be electrically "quiet" ?).
> Best Regards,
> Chuck Olson, WB9KZY
> Jackson Harbor Press - Ham Radio Kits and more!
> Washington Island, WI
> <>

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