Philips UHF 40ch Radio

[CyBorg 0091]

A person hooked the CB UHF radio to a car battery and it stopped working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

 

[Dr LG]

Size of the cable isn't a worrie just cross polarity is a bad thing. Might
be as easy as removing a now busted diode but i doubt it.

"CyBorg 0091" <non@no.na> wrote in message
news:3f728b16$1@news.comindico.com.au...

A person hooked the CB UHF radio to a car battery and it stopped
working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

 

[budgie]

On Thu, 25 Sep 2003 06:28:39 GMT, "CyBorg 0091" <non@no.na> wrote:

A person hooked the CB UHF radio to a car battery and it stopped working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

No such thing. Excessive voltage could do it eg 24V vehicle and poor
iddle widdle 12V radio.

Most likely cause? Some idiot (not you, 'cause you said it wasn't you
- yeah, right, sure) connected it up arse-about.

Depending on how - if at all - the model in question is reverse
polarity protected, will determine what may have gone pfutt!

Crowbar diode and fuse combo will take out PCB track as often as the
fuse. Crowbar and NO fuse (on the assumption that you WILL have a
fuse in the power leads, not a valid assumption when you use welding
flexible to feed it) will certainly smoke some track.

And if the protection system didn't seriously clamp the negative (wrt
radio chassis) voltage excursiuon, expect the semiconductor devices to
be u/s.

 

[mikeqld]

Get over it. It was only a cb radio. Dime a dozen for uhf models and even
cheaper for the hf ones.

"budgie" <budgie@nowhere.cantech.net.au> wrote in message
news:3f72a9cd.13760434@news.cantech.net.au...

On Thu, 25 Sep 2003 06:28:39 GMT, "CyBorg 0091" <non@no.na> wrote:

A person hooked the CB UHF radio to a car battery and it stopped
working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

No such thing. Excessive voltage could do it eg 24V vehicle and poor
iddle widdle 12V radio.

Most likely cause? Some idiot (not you, 'cause you said it wasn't you
- yeah, right, sure) connected it up arse-about.

Depending on how - if at all - the model in question is reverse
polarity protected, will determine what may have gone pfutt!

Crowbar diode and fuse combo will take out PCB track as often as the
fuse. Crowbar and NO fuse (on the assumption that you WILL have a
fuse in the power leads, not a valid assumption when you use welding
flexible to feed it) will certainly smoke some track.

And if the protection system didn't seriously clamp the negative (wrt
radio chassis) voltage excursiuon, expect the semiconductor devices to
be u/s.

 

[Dr LG]

Your not one of those peep who pat there radio in the morning, talk to it
thru the day and say good night to it on your way to bed i can tell....


"mikeqld" <Only@Reply.On.News.Group.com> wrote in message
news:Cpycb.122353$bo1.85945@news-server.bigpond.net.au...

Get over it. It was only a cb radio. Dime a dozen for uhf models and even
cheaper for the hf ones.

"budgie" <budgie@nowhere.cantech.net.au> wrote in message
news:3f72a9cd.13760434@news.cantech.net.au...
On Thu, 25 Sep 2003 06:28:39 GMT, "CyBorg 0091" <non@no.na> wrote:

A person hooked the CB UHF radio to a car battery and it stopped
working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

No such thing. Excessive voltage could do it eg 24V vehicle and poor
iddle widdle 12V radio.

Most likely cause? Some idiot (not you, 'cause you said it wasn't you
- yeah, right, sure) connected it up arse-about.

Depending on how - if at all - the model in question is reverse
polarity protected, will determine what may have gone pfutt!

Crowbar diode and fuse combo will take out PCB track as often as the
fuse. Crowbar and NO fuse (on the assumption that you WILL have a
fuse in the power leads, not a valid assumption when you use welding
flexible to feed it) will certainly smoke some track.

And if the protection system didn't seriously clamp the negative (wrt
radio chassis) voltage excursiuon, expect the semiconductor devices to
be u/s.

 

[CyBorg 0091]

I think he obviously blew the fuse somehow,could not find a replacement then
started trying to get it to run without a fuse and in the frustration
obviously possibly connected it arse-about from what you suggest.


It is a Philips FM620 UHF 40channel.

Ok I think I need to learn more about testing and tracking semiconductor
devices before playing with this thing.
I am gathering you are suggesting it could have taken almost all devices not
just one or two then gave up.
It dose not seem to have much protection from anything from where I look at
it.


"budgie" <budgie@nowhere.cantech.net.au> wrote in message
news:3f72a9cd.13760434@news.cantech.net.au...

On Thu, 25 Sep 2003 06:28:39 GMT, "CyBorg 0091" <non@no.na> wrote:

A person hooked the CB UHF radio to a car battery and it stopped
working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

No such thing. Excessive voltage could do it eg 24V vehicle and poor
iddle widdle 12V radio.

Most likely cause? Some idiot (not you, 'cause you said it wasn't you
- yeah, right, sure) connected it up arse-about.

Depending on how - if at all - the model in question is reverse
polarity protected, will determine what may have gone pfutt!

Crowbar diode and fuse combo will take out PCB track as often as the
fuse. Crowbar and NO fuse (on the assumption that you WILL have a
fuse in the power leads, not a valid assumption when you use welding
flexible to feed it) will certainly smoke some track.

And if the protection system didn't seriously clamp the negative (wrt
radio chassis) voltage excursiuon, expect the semiconductor devices to
be u/s.

 

[CyBorg 0091]

Thats comforting....

Thanks.
"Dr LG" <drlimegreen@yahoo.com.au> wrote in message
news:bku86d$1aij$1@otis.netspace.net.au...

Size of the cable isn't a worrie just cross polarity is a bad thing. Might
be as easy as removing a now busted diode but i doubt it.

"CyBorg 0091" <non@no.na> wrote in message
news:3f728b16$1@news.comindico.com.au...
A person hooked the CB UHF radio to a car battery and it stopped
working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

 

[budgie]

On Thu, 25 Sep 2003 09:18:26 GMT, "mikeqld"
<Only@Reply.On.News.Group.com> wrote:

Get over it. It was only a cb radio. Dime a dozen for uhf models and even
cheaper for the hf ones.

Don't tell me that, try telling the O/P.

 

[Martin, VK2UMJ]

"CyBorg 0091" <non@no.na> wrote in message
news:3f72bf73@news.comindico.com.au...

I think he obviously blew the fuse somehow,could not find a replacement
then
started trying to get it to run without a fuse and in the frustration
obviously possibly connected it arse-about from what you suggest.

Most likely connected it up reversed, which blew the fuse. If he then
replaced the fuse with, say a large nail!!!, then you can possibly write the
radio off and use it as a door stop or paper weight. If, however, he didn't
try bypassing the fuse when it blew, then you may have a good chance of
fixing it.

It is a Philips FM620 UHF 40channel.

Worth about $50, maybe $100 at the very most. Easily replaced, and probably
better off doing so with something much better!!

Ok I think I need to learn more about testing and tracking semiconductor
devices before playing with this thing.
I am gathering you are suggesting it could have taken almost all devices
not
just one or two then gave up.
It dose not seem to have much protection from anything from where I look
at
it.

Most likely first casualty will be the reverse protection diode, usually
located across the power input and close to where the positive & negative
wires connect to the pcb. It'll be the diode that is either burnt or falls
apart when touched!! You can cut one leg of this diode and then test the
radio before you go to the trouble of replacing it. If further damage has
been done, given the value of these things, toss it!! Otherwise, replace
that diode with a 1N4002 or 1N4004, or whatever is handy...

What area are you in? Perhaps someone nearby can offer to help you identify
the relevant parts.....

Cheers

Martin, VK2UMJ

"budgie" <budgie@nowhere.cantech.net.au> wrote in message
news:3f72a9cd.13760434@news.cantech.net.au...
On Thu, 25 Sep 2003 06:28:39 GMT, "CyBorg 0091" <non@no.na> wrote:

A person hooked the CB UHF radio to a car battery and it stopped
working.The
only reason I could gather it stopped was he ran wires the size of car
battery cables to it.(no not me)
I can see nothing burned out.

What is its problem and what would be the first thing to query for an
excessive supply of power blowing it up.

No such thing. Excessive voltage could do it eg 24V vehicle and poor
iddle widdle 12V radio.

Most likely cause? Some idiot (not you, 'cause you said it wasn't you
- yeah, right, sure) connected it up arse-about.

Depending on how - if at all - the model in question is reverse
polarity protected, will determine what may have gone pfutt!

Crowbar diode and fuse combo will take out PCB track as often as the
fuse. Crowbar and NO fuse (on the assumption that you WILL have a
fuse in the power leads, not a valid assumption when you use welding
flexible to feed it) will certainly smoke some track.

And if the protection system didn't seriously clamp the negative (wrt
radio chassis) voltage excursiuon, expect the semiconductor devices to
be u/s.

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