Best circiut to power CB radio

Where is the best place to splice in a CB on a 2000 Disco? Please forgive
my reverence, I didn't find this a hard decision on my Wrangler or my F150,
but my Rover is wired up like the Starship Enterprise. I'm just
looking for an opinion about where to get my 12V DC.

--
Derek Hanks


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Derek Hanks wrote:
> Where is the best place to splice in a CB on a 2000 Disco? Please forgive
> my reverence, I didn't find this a hard decision on my Wrangler or my F150,
> but my Rover is wired up like the Starship Enterprise. I'm just
> looking for an opinion about where to get my 12V DC.
>

I've never even seen a 2000 Disco up close, so I can't help you in terms
of the layout of the electrics, however from the radio's perspective,
it's best if you run wires all the way to the battery. You need to make
sure you switch off the radio when not in use, but even if you don't, it
shouldn't be a problem as most radios don't drain much current when
receiving anyway.

Connecting it directly to the battery will provide higher voltage to the
radio, which in turn should maximise your power output.

>Subject: Best circiut to power CB radio
>From: "Derek Hanks" [email protected]
>Date: 14/10/2004 03:24 GMT

>Where is the best place to splice in a CB on a 2000 Disco?<snip>

Direct from the battery.

Steve. Suffolk.
remove 'knujon' to e-mail

"AN6530" <[email protected]> wrote in message
news:[email protected]...
> >Subject: Best circiut to power CB radio
> >From: "Derek Hanks" [email protected]
> >Date: 14/10/2004 03:24 GMT
>
> >Where is the best place to splice in a CB on a 2000 Disco?<snip>
>
> Direct from the battery.
>
> Steve. Suffolk.
> remove 'knujon' to e-mail
>

Don't forget to put an in line fuse in to both the +ve and the -ve if
connecting directly on to the battery posts, as close to the battery as
possible.
Alternatively connect the -ve to chassis and just an inline fuse in the +ve
line.

R2D2 wrote:

>
> Don't forget to put an in line fuse in to both the +ve and the -ve if
> connecting directly on to the battery posts, as close to the battery as
> possible.

What purpose does a fuse in the -ve feed serve, other than one more
potential cause of a dodgy connection?


--
EMB
change two to the number to reply

"EMB" <[email protected]> wrote in message
news:[email protected]...
> R2D2 wrote:
>
> >
> > Don't forget to put an in line fuse in to both the +ve and the -ve if
> > connecting directly on to the battery posts, as close to the battery as
> > possible.
>
> What purpose does a fuse in the -ve feed serve, other than one more
> potential cause of a dodgy connection?
>
>
> --
> EMB
> change two to the number to reply

The idea is that if the main earth to the vehicle's engine fails, when you
go to crank the engine, it doesn't draw a massive amount of current through
the radio and damage it but instead it blows the fuse.
This is the guideline laid down under MPT1362 for installation of radio
equipment in to land based vehicles.
If you connect the -ve down to the vehicles chassis it is then not necessary
to incorporate a fuse in to the -ve line.
I hope this answers your question my friend.

R2D2 wrote:
>
> The idea is that if the main earth to the vehicle's engine fails, when you
> go to crank the engine, it doesn't draw a massive amount of current through
> the radio and damage it but instead it blows the fuse.
> This is the guideline laid down under MPT1362 for installation of radio
> equipment in to land based vehicles.
> If you connect the -ve down to the vehicles chassis it is then not necessary
> to incorporate a fuse in to the -ve line.
> I hope this answers your question my friend.

Thanks - it makes sense.


--
EMB
change two to the number to reply

On or around Fri, 15 Oct 2004 08:08:45 +1300, EMB <[email protected]>
enlightened us thusly:

>R2D2 wrote:
>
>>
>> Don't forget to put an in line fuse in to both the +ve and the -ve if
>> connecting directly on to the battery posts, as close to the battery as
>> possible.
>
>What purpose does a fuse in the -ve feed serve, other than one more
>potential cause of a dodgy connection?

bugger all, I expect.

I'd be inclined to hunt a permanent live from the fusebox. You might even
find a spare fuse, or feed it from the interior light circuit or something.
Most CB installations have their own fuse anyway, inline.

"Austin Shackles" <[email protected]> wrote in message
news:[email protected]...
> On or around Fri, 15 Oct 2004 08:08:45 +1300, EMB <[email protected]>
> enlightened us thusly:
>
> >R2D2 wrote:
> >
> >>
> >> Don't forget to put an in line fuse in to both the +ve and the -ve if
> >> connecting directly on to the battery posts, as close to the battery as
> >> possible.
> >
> >What purpose does a fuse in the -ve feed serve, other than one more
> >potential cause of a dodgy connection?
>
> bugger all, I expect.
>
> I'd be inclined to hunt a permanent live from the fusebox. You might even
> find a spare fuse, or feed it from the interior light circuit or
something.
> Most CB installations have their own fuse anyway, inline.
>


It's permissible to find an alternative feed for a transceiver radio but you
have to be careful and sensible about it!
It's ok to connect to a main cable, i.e., a main feed to or from the
ignition switch as there is plenty of current at this point and hardly any
voltage drop.
Depending on whether you want the radio to be powered up permanently or
whether you want the radio to be ignition switched is another question.
you have to weigh up the prose and cons, for instants, if you connect the
radio so that it isn't ignition switched and you accidentally leave the
radio switched on all weekend you may well have a flat battery on monday
morning especially if the battery is getting a little old and tired.
On the other hand, if you connect the radio so that it is not ignition
switched you may well be tempted to leave the keys in the ignition to keep
the radio alive especially if you are not to far away from the vehicle and
are waiting for a call over the radio from somebody
In the latter case you may be distracted for a moment and the next thing you
know is your pride and joy is off down the road, leaving you without a
vehicle and void insurance.
I have known the latter happen and in my opinion it's far better to suffer a
flat battery than a lost motor vehicle.
Connecting to an interior light and other such circuits is a no no. Why?
PMR devises such as CB radios etc are capable of drawing up to 15 amps, and
more, when in transmit mode, depending on what the power output level has
been set at.
I have seen many burned out wiring looms and horrendously expensive damage
over the years because people have connected these devises to inadequate
power supply sources on vehicles.
On more modern vehicles problems can arise when electrical devises are
connected in to wiring loom as serial data is transmitted along these cables
and this can cause corruption and damage to the vehicle's ECU's.
So either connect on to a heavy cable around the ignition switch or better
still go straight to the vehicle's battery,
Use good quality water proof fuse holders and you wont have a problem.

Thanks much for the info. My Jeep had a switched accessory circuit so it
was very nice. I was hoping for an option like that on the Rover that I was
overlooking. I believe I just piggy backed on the stereo circuit for my
truck.

It seems clear my best option is to wire direct to the battery and mind my
power switch. I have a ham radio that has been tweaked for extra power
output even in the CB bands, so concerns about too much amperage being drawn
are warranted.


"R2D2" <[email protected]> wrote in message
news:[email protected]...
>
> "Austin Shackles" <[email protected]> wrote in message
> news:[email protected]...
>> On or around Fri, 15 Oct 2004 08:08:45 +1300, EMB <[email protected]>
>> enlightened us thusly:
>>
>> >R2D2 wrote:
>> >
>> >>
>> >> Don't forget to put an in line fuse in to both the +ve and the -ve if
>> >> connecting directly on to the battery posts, as close to the battery
>> >> as
>> >> possible.
>> >
>> >What purpose does a fuse in the -ve feed serve, other than one more
>> >potential cause of a dodgy connection?
>>
>> bugger all, I expect.
>>
>> I'd be inclined to hunt a permanent live from the fusebox. You might
>> even
>> find a spare fuse, or feed it from the interior light circuit or
> something.
>> Most CB installations have their own fuse anyway, inline.
>>
>
>
> It's permissible to find an alternative feed for a transceiver radio but
> you
> have to be careful and sensible about it!
> It's ok to connect to a main cable, i.e., a main feed to or from the
> ignition switch as there is plenty of current at this point and hardly any
> voltage drop.
> Depending on whether you want the radio to be powered up permanently or
> whether you want the radio to be ignition switched is another question.
> you have to weigh up the prose and cons, for instants, if you connect the
> radio so that it isn't ignition switched and you accidentally leave the
> radio switched on all weekend you may well have a flat battery on monday
> morning especially if the battery is getting a little old and tired.
> On the other hand, if you connect the radio so that it is not ignition
> switched you may well be tempted to leave the keys in the ignition to keep
> the radio alive especially if you are not to far away from the vehicle and
> are waiting for a call over the radio from somebody
> In the latter case you may be distracted for a moment and the next thing
> you
> know is your pride and joy is off down the road, leaving you without a
> vehicle and void insurance.
> I have known the latter happen and in my opinion it's far better to suffer
> a
> flat battery than a lost motor vehicle.
> Connecting to an interior light and other such circuits is a no no. Why?
> PMR devises such as CB radios etc are capable of drawing up to 15 amps,
> and
> more, when in transmit mode, depending on what the power output level has
> been set at.
> I have seen many burned out wiring looms and horrendously expensive damage
> over the years because people have connected these devises to inadequate
> power supply sources on vehicles.
> On more modern vehicles problems can arise when electrical devises are
> connected in to wiring loom as serial data is transmitted along these
> cables
> and this can cause corruption and damage to the vehicle's ECU's.
> So either connect on to a heavy cable around the ignition switch or better
> still go straight to the vehicle's battery,
> Use good quality water proof fuse holders and you wont have a problem.
>
>
>

"Derek Hanks" <[email protected]> wrote in message
news:[email protected]...
> Thanks much for the info. My Jeep had a switched accessory circuit so it
> was very nice. I was hoping for an option like that on the Rover that I
was
> overlooking. I believe I just piggy backed on the stereo circuit for my
> truck.
>
> It seems clear my best option is to wire direct to the battery and mind my
> power switch. I have a ham radio that has been tweaked for extra power
> output even in the CB bands, so concerns about too much amperage being
drawn
> are warranted.
>
>
> "R2D2" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Austin Shackles" <[email protected]> wrote in message
> > news:[email protected]...
> >> On or around Fri, 15 Oct 2004 08:08:45 +1300, EMB <[email protected]>
> >> enlightened us thusly:
> >>
> >> >R2D2 wrote:
> >> >
> >> >>
> >> >> Don't forget to put an in line fuse in to both the +ve and the -ve
if
> >> >> connecting directly on to the battery posts, as close to the battery
> >> >> as
> >> >> possible.
> >> >
> >> >What purpose does a fuse in the -ve feed serve, other than one more
> >> >potential cause of a dodgy connection?
> >>
> >> bugger all, I expect.
> >>
> >> I'd be inclined to hunt a permanent live from the fusebox. You might
> >> even
> >> find a spare fuse, or feed it from the interior light circuit or
> > something.
> >> Most CB installations have their own fuse anyway, inline.
> >>
> >
> >
> > It's permissible to find an alternative feed for a transceiver radio but
> > you
> > have to be careful and sensible about it!
> > It's ok to connect to a main cable, i.e., a main feed to or from the
> > ignition switch as there is plenty of current at this point and hardly
any
> > voltage drop.
> > Depending on whether you want the radio to be powered up permanently or
> > whether you want the radio to be ignition switched is another question.
> > you have to weigh up the prose and cons, for instants, if you connect
the
> > radio so that it isn't ignition switched and you accidentally leave the
> > radio switched on all weekend you may well have a flat battery on monday
> > morning especially if the battery is getting a little old and tired.
> > On the other hand, if you connect the radio so that it is not ignition
> > switched you may well be tempted to leave the keys in the ignition to
keep
> > the radio alive especially if you are not to far away from the vehicle
and
> > are waiting for a call over the radio from somebody
> > In the latter case you may be distracted for a moment and the next thing
> > you
> > know is your pride and joy is off down the road, leaving you without a
> > vehicle and void insurance.
> > I have known the latter happen and in my opinion it's far better to
suffer
> > a
> > flat battery than a lost motor vehicle.
> > Connecting to an interior light and other such circuits is a no no.
Why?
> > PMR devises such as CB radios etc are capable of drawing up to 15 amps,
> > and
> > more, when in transmit mode, depending on what the power output level
has
> > been set at.
> > I have seen many burned out wiring looms and horrendously expensive
damage
> > over the years because people have connected these devises to inadequate
> > power supply sources on vehicles.
> > On more modern vehicles problems can arise when electrical devises are
> > connected in to wiring loom as serial data is transmitted along these
> > cables
> > and this can cause corruption and damage to the vehicle's ECU's.
> > So either connect on to a heavy cable around the ignition switch or
better
> > still go straight to the vehicle's battery,
> > Use good quality water proof fuse holders and you wont have a problem.
> >
> >
You are very welcome.

On Thursday, in article <[email protected]>
[email protected] "Derek Hanks" wrote:

> Thanks much for the info. My Jeep had a switched accessory circuit so it
> was very nice. I was hoping for an option like that on the Rover that I was
> overlooking. I believe I just piggy backed on the stereo circuit for my
> truck.
>
> It seems clear my best option is to wire direct to the battery and mind my
> power switch. I have a ham radio that has been tweaked for extra power
> output even in the CB bands, so concerns about too much amperage being drawn
> are warranted.

Could something be done with a relay?

Have an "auxiliary power" switch in parallel with the ignition switch,
controlling a relay which switches the power to the radio.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."

""David G. Bell"" <[email protected]> wrote in message
news:[email protected]...
> On Thursday, in article <[email protected]>
> [email protected] "Derek Hanks" wrote:
>
> > Thanks much for the info. My Jeep had a switched accessory circuit so
it
> > was very nice. I was hoping for an option like that on the Rover that I
was
> > overlooking. I believe I just piggy backed on the stereo circuit for my
> > truck.
> >
> > It seems clear my best option is to wire direct to the battery and mind
my
> > power switch. I have a ham radio that has been tweaked for extra power
> > output even in the CB bands, so concerns about too much amperage being
drawn
> > are warranted.
>
> Could something be done with a relay?
>
> Have an "auxiliary power" switch in parallel with the ignition switch,
> controlling a relay which switches the power to the radio.
>
> --
> David G. Bell -- SF Fan, Filker, and Punslinger.
>
> "History shows that the Singularity started when Sir Tim Berners-Lee
> was bitten by a radioactive spider."

It certainly could, no problem at all.
It would get round the possible flat battery scenario.

On Friday, in article <[email protected]>
[email protected] "R2D2" wrote:

> ""David G. Bell"" <[email protected]> wrote in message
> news:[email protected]...
> > On Thursday, in article <[email protected]>
> > [email protected] "Derek Hanks" wrote:
> >
> > > Thanks much for the info. My Jeep had a switched accessory circuit so
> it
> > > was very nice. I was hoping for an option like that on the Rover that I
> was
> > > overlooking. I believe I just piggy backed on the stereo circuit for my
> > > truck.
> > >
> > > It seems clear my best option is to wire direct to the battery and mind
> my
> > > power switch. I have a ham radio that has been tweaked for extra power
> > > output even in the CB bands, so concerns about too much amperage being
> drawn
> > > are warranted.
> >
> > Could something be done with a relay?
> >
> > Have an "auxiliary power" switch in parallel with the ignition switch,
> > controlling a relay which switches the power to the radio.
>
> It certainly could, no problem at all.
> It would get round the possible flat battery scenario.

You would need a diode between the ignition switch and the relay, so
that current wouldn't go through the auxiliary switch to bypass the
ignition. Not a problem -- the relay coil is low current.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."

""David G. Bell"" <[email protected]> wrote in message
news:[email protected]...
> On Friday, in article <[email protected]>
> [email protected] "R2D2" wrote:
>
> > ""David G. Bell"" <[email protected]> wrote in message
> > news:[email protected]...
> > > On Thursday, in article <[email protected]>
> > > [email protected] "Derek Hanks" wrote:
> > >
> > > > Thanks much for the info. My Jeep had a switched accessory circuit
so
> > it
> > > > was very nice. I was hoping for an option like that on the Rover
that I
> > was
> > > > overlooking. I believe I just piggy backed on the stereo circuit
for my
> > > > truck.
> > > >
> > > > It seems clear my best option is to wire direct to the battery and
mind
> > my
> > > > power switch. I have a ham radio that has been tweaked for extra
power
> > > > output even in the CB bands, so concerns about too much amperage
being
> > drawn
> > > > are warranted.
> > >
> > > Could something be done with a relay?
> > >
> > > Have an "auxiliary power" switch in parallel with the ignition switch,
> > > controlling a relay which switches the power to the radio.
> >
> > It certainly could, no problem at all.
> > It would get round the possible flat battery scenario.
>
> You would need a diode between the ignition switch and the relay, so
> that current wouldn't go through the auxiliary switch to bypass the
> ignition. Not a problem -- the relay coil is low current.
>
> --
> David G. Bell -- SF Fan, Filker, and Punslinger.
>
> "History shows that the Singularity started when Sir Tim Berners-Lee
> was bitten by a radioactive spider."

You wouldn't really need a diode as all you need to do is connect one side
of the voltage coil to the switched side of the ignition switch and the over
side down to earth/chassis.

On Saturday, in article <[email protected]>
[email protected] "R2D2" wrote:

> ""David G. Bell"" <[email protected]> wrote in message
> news:[email protected]...
> > On Friday, in article <[email protected]>
> > [email protected] "R2D2" wrote:
> >
> > > ""David G. Bell"" <[email protected]> wrote in message
> > > news:[email protected]...
> > > > On Thursday, in article <[email protected]>
> > > > [email protected] "Derek Hanks" wrote:
> > > >
> > > > > Thanks much for the info. My Jeep had a switched accessory circuit
> so
> > > it
> > > > > was very nice. I was hoping for an option like that on the Rover
> that I
> > > was
> > > > > overlooking. I believe I just piggy backed on the stereo circuit
> for my
> > > > > truck.
> > > > >
> > > > > It seems clear my best option is to wire direct to the battery and
> mind
> > > my
> > > > > power switch. I have a ham radio that has been tweaked for extra
> power
> > > > > output even in the CB bands, so concerns about too much amperage
> being
> > > drawn
> > > > > are warranted.
> > > >
> > > > Could something be done with a relay?
> > > >
> > > > Have an "auxiliary power" switch in parallel with the ignition switch,
> > > > controlling a relay which switches the power to the radio.
> > >
> > > It certainly could, no problem at all.
> > > It would get round the possible flat battery scenario.
> >
> > You would need a diode between the ignition switch and the relay, so
> > that current wouldn't go through the auxiliary switch to bypass the
> > ignition. Not a problem -- the relay coil is low current.
>
> You wouldn't really need a diode as all you need to do is connect one side
> of the voltage coil to the switched side of the ignition switch and the over
> side down to earth/chassis.

I think it's been lost in quoting, though you can see a trace of it, but
the idea was partly to have an auxiliary-power switch so that the radio
could be powered without the key needing to be in the ignition.

It's possible to use a three relays so that the auxiliary switch is a
momentary contact, and the ignition circuit switches the auxiliary input
off when it goes live.

Relay A -- coil powered through auxiliary switch. When contacts close,
output also feeds coil through Relay B, so the output remains live as
long as Relay B contacts are closed.

Relay B -- coil powered from ignition switch. Uses n\c contacts for
latching circuit for Relay A.

Relay C -- coil powered by both Relay A output and ignition switch, the
latter through a diode. Switches power to radio.


With this system, or a solid-state equivalent, the power to the radio
circuit can be switched on by pressing the auxiliary button, if the
ignition is off. You might want some sort of warning light.

Next week: How to build a computer in the back of yout 101 from the LR
Spares Catalogue.

--
David G. Bell -- SF Fan, Filker, and Punslinger.

"History shows that the Singularity started when Sir Tim Berners-Lee
was bitten by a radioactive spider."

""David G. Bell"" <[email protected]> wrote in message
news:[email protected]...
> On Saturday, in article <[email protected]>
> [email protected] "R2D2" wrote:
>
> > ""David G. Bell"" <[email protected]> wrote in message
> > news:[email protected]...
> > > On Friday, in article <[email protected]>
> > > [email protected] "R2D2" wrote:
> > >
> > > > ""David G. Bell"" <[email protected]> wrote in message
> > > > news:[email protected]...
> > > > > On Thursday, in article <[email protected]>
> > > > > [email protected] "Derek Hanks" wrote:
> > > > >
> > > > > > Thanks much for the info. My Jeep had a switched accessory
circuit
> > so
> > > > it
> > > > > > was very nice. I was hoping for an option like that on the
Rover
> > that I
> > > > was
> > > > > > overlooking. I believe I just piggy backed on the stereo
circuit
> > for my
> > > > > > truck.
> > > > > >
> > > > > > It seems clear my best option is to wire direct to the battery
and
> > mind
> > > > my
> > > > > > power switch. I have a ham radio that has been tweaked for
extra
> > power
> > > > > > output even in the CB bands, so concerns about too much amperage
> > being
> > > > drawn
> > > > > > are warranted.
> > > > >
> > > > > Could something be done with a relay?
> > > > >
> > > > > Have an "auxiliary power" switch in parallel with the ignition
switch,
> > > > > controlling a relay which switches the power to the radio.
> > > >
> > > > It certainly could, no problem at all.
> > > > It would get round the possible flat battery scenario.
> > >
> > > You would need a diode between the ignition switch and the relay, so
> > > that current wouldn't go through the auxiliary switch to bypass the
> > > ignition. Not a problem -- the relay coil is low current.
> >
> > You wouldn't really need a diode as all you need to do is connect one
side
> > of the voltage coil to the switched side of the ignition switch and the
over
> > side down to earth/chassis.
>
> I think it's been lost in quoting, though you can see a trace of it, but
> the idea was partly to have an auxiliary-power switch so that the radio
> could be powered without the key needing to be in the ignition.
>
> It's possible to use a three relays so that the auxiliary switch is a
> momentary contact, and the ignition circuit switches the auxiliary input
> off when it goes live.
>
> Relay A -- coil powered through auxiliary switch. When contacts close,
> output also feeds coil through Relay B, so the output remains live as
> long as Relay B contacts are closed.
>
> Relay B -- coil powered from ignition switch. Uses n\c contacts for
> latching circuit for Relay A.
>
> Relay C -- coil powered by both Relay A output and ignition switch, the
> latter through a diode. Switches power to radio.
>
>
> With this system, or a solid-state equivalent, the power to the radio
> circuit can be switched on by pressing the auxiliary button, if the
> ignition is off. You might want some sort of warning light.
>
> Next week: How to build a computer in the back of yout 101 from the LR
> Spares Catalogue.
>
> --
> David G. Bell -- SF Fan, Filker, and Punslinger.
>
> "History shows that the Singularity started when Sir Tim Berners-Lee
> was bitten by a radioactive spider."

I guess you could do it that way but you would need a heavy rated diode
because of the amount of current drawn when transmitting.

> Next week: How to build a computer in the back of yout 101 from the LR
> Spares Catalogue.


did'nt know you could still get the valves for it )