Do any of you know the characteristics of the cigarette lighter adapter
that is used with the Yaesu/Vertex VXA-700 2 meter and airband HT?

Does it just convey the 12 volts (or 13.8 volts or 14.2 volts or whatever
it is at any moment in time) directly to the HT, or is there any kind of
filter or voltage limiter that's internal to the adapter?

In other words, can I just feed 13.8 volts directly from a car battery to
the HT to run it and charge the battery?

Looked on the Yaesu and Vertex Standard websites for information and
couldn't find any reference at all to the VXA-700 ... wonder if it has
been discontinued...

"Rick" wrote in message
news

Do any of you know the characteristics of the cigarette lighter adapter
that is used with the Yaesu/Vertex VXA-700 2 meter and airband HT?

Does it just convey the 12 volts (or 13.8 volts or 14.2 volts or whatever
it is at any moment in time) directly to the HT, or is there any kind of
filter or voltage limiter that's internal to the adapter?

In other words, can I just feed 13.8 volts directly from a car battery to
the HT to run it and charge the battery?

Looked on the Yaesu and Vertex Standard websites for information and
couldn't find any reference at all to the VXA-700 ... wonder if it has
been discontinued...


OK using a bit of 'sideways logic' I see that the 12V 'adaptor' (E-DC-5B DC
Cable with Cigarette Lighter Plug) listed for this radio also cross
references to a yaesu handy (VR500) I've got that, quite happily, takes a
'neat' 12V in to charge the 2 'AA' cells that are in the radio. So I would
say the 13.8V from your car would be fine.

On Tue, 27 Mar 2007 20:42:30 +0000, Brian MW0GKX wrote:

OK using a bit of 'sideways logic' I see that the 12V 'adaptor' (E-DC-5B DC
Cable with Cigarette Lighter Plug) listed for this radio also cross
references to a yaesu handy (VR500) I've got that, quite happily, takes a
'neat' 12V in to charge the 2 'AA' cells that are in the radio. So I would
say the 13.8V from your car would be fine.

Good afternoon, Brian.

The point of my question was, I want to fabricate a DC power cord for the
VXA-700 with a Powerpole connector on one end, and I need to know if I can
just feed 12 volts into the side of the VXA-700, or does their cigarette
lighter adapter have some kind of voltage reduction or current limiting
circuitry in there?

In article ,
Rick wrote:

The point of my question was, I want to fabricate a DC power cord for the
VXA-700 with a Powerpole connector on one end, and I need to know if I can
just feed 12 volts into the side of the VXA-700, or does their cigarette
lighter adapter have some kind of voltage reduction or current limiting
circuitry in there?

The Yaesu adapter which I bought for use with my VX-5 apparently
contains a surge suppressor (a varactor or zener, I suppose) and a
fuse.

I believe that the intent is to make sure that a high-voltage spike on
the car wiring (triggered by "load dump" - e.g. turning off the
headlights and thus abruptly reducing the current load on the system
when the alternator is running) doesn't reach and burn out the radio.
Automotive electronics for "12-volt" systems are normally engineered
to be able to withstand a short spike of as much as 50 volts above
ground... that's the magnitude of what you have to be concerned about.

I've fed my VX-5 power directly from a 12-volt gel cell which was not
connected to a car electrical system, and it was perfectly happy with
it. If that's all you're planning on doing, you can probably just use
the PowerPole arrangement.

If you plan to have the radio plugged into the lighter outlet when the
car is turned on, however, it'd be safer for you to provide some
voltage clamping and filtering, just as Yaesu does.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Rick" wrote in message
news
On Tue, 27 Mar 2007 20:42:30 +0000, Brian MW0GKX wrote:

OK using a bit of 'sideways logic' I see that the 12V 'adaptor' (E-DC-5B
DC
Cable with Cigarette Lighter Plug) listed for this radio also cross
references to a yaesu handy (VR500) I've got that, quite happily, takes a
'neat' 12V in to charge the 2 'AA' cells that are in the radio. So I
would
say the 13.8V from your car would be fine.

Good afternoon, Brian.

The point of my question was, I want to fabricate a DC power cord for the
VXA-700 with a Powerpole connector on one end, and I need to know if I can
just feed 12 volts into the side of the VXA-700, or does their cigarette
lighter adapter have some kind of voltage reduction or current limiting
circuitry in there?


AFAIK noise suppression and spike removal is all thats in the box, and maybe
a fuse.

For current limiting, use a 2 amp fuse in the supply.

Also note that they sell a lead with no plug on the far end to connect the
radio to a shacks supply.