I have a mobile ham radio that I would like to use as a fixed station
in my home. As this is a non-standard use of the radio, I have found
a possible solution in the way of an external Dell Optiplex AC/DC
Power Supply that should provide the necessary voltage (12v) and
amperage (12a) to power it. I've collected the necessary parts to
create an adapter between the standard Molex style 8-pin female end of
the Optiplex Power Supply and the 2-pin female end of the ham radio.

I've learned that in order to power the Optiplex Power Supply, the #5
pin must be grounded to one of the #6, #7, or #8 pins and the positive
voltage is delivered by the #2, #3, and #4 pins.

http://www.powerstream.com/ac-12180.htm

My question is... In the adapter that I am creating, is it necessary
to use all three of the positive voltage pins (i.e., #2, #3, #4) from
the Optiplex Power Supply and all three of the negative grounding pins
(i.e., #6, #7, #8) to supply voltage to the single positive voltage
pin and the single negative grounding pin of the ham radio? Or should
it only be necessary to use one positive voltage and one negative
grounding pin to connect to the 2-pin ham radio?

Also, If I connect the #5 remote pin to one of the #6, #7, or #8
grounding pins can I also use that same grounding pin to connect to
the negative grounding pin on the ham radio?

Thank you for your assistance.

Respectfully,


Gary

In article
,
wrote:
I have a mobile ham radio that I would like to use as a fixed station
in my home. As this is a non-standard use of the radio, I have found
a possible solution in the way of an external Dell Optiplex AC/DC
Power Supply that should provide the necessary voltage (12v) and
amperage (12a) to power it.

Most commercial power supplies designed for this sort of thing produce
13.8 volts. This is approx the voltage with the engine running in a car
with 12 volt electrics. 12 volts equates to a nearly flat battery - and
your rig may not perform correctly with this.

--
*Always drink upstream from the herd *

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

In article
,
wrote:
I have a mobile ham radio that I would like to use as a fixed station
in my home. As this is a non-standard use of the radio, I have found
a possible solution in the way of an external Dell Optiplex AC/DC
Power Supply that should provide the necessary voltage (12v) and
amperage (12a) to power it.

My question is... Â*In the adapter that I am creating, is it necessary
to use all three of the positive voltage pins (i.e., #2, #3, #4) from
the Optiplex Power Supply and all three of the negative grounding pins
(i.e., #6, #7, #8) Â*to supply voltage to the single positive voltage
pin and the single negative grounding pin of the ham radio? Â*Or should
it only be necessary to use one positive voltage and one negative
grounding pin to connect to the 2-pin ham radio?

Most commercial power supplies designed for this sort of thing produce
13.8 volts. This is approx the voltage with the engine running in a
car with 12 volt electrics. 12 volts equates to a nearly flat
battery - and your rig may not perform correctly with this.


Whilst Dave is correct it did not answer your question ! All the
positives will be connected together as will all the negatives. The
reason that there are three pins in the plug for each rail is that the
current rating of each pin is only 4 amps.

--
Best Regards:
Baron.

In article ,
Baron wrote:
Dave Plowman (News) wrote:

In article
,
wrote:
I have a mobile ham radio that I would like to use as a fixed station
in my home. As this is a non-standard use of the radio, I have found
a possible solution in the way of an external Dell Optiplex AC/DC
Power Supply that should provide the necessary voltage (12v) and
amperage (12a) to power it.

My question is... In the adapter that I am creating, is it necessary
to use all three of the positive voltage pins (i.e., #2, #3, #4) from
the Optiplex Power Supply and all three of the negative grounding pins
(i.e., #6, #7, #8) to supply voltage to the single positive voltage
pin and the single negative grounding pin of the ham radio? Or should
it only be necessary to use one positive voltage and one negative
grounding pin to connect to the 2-pin ham radio?

Most commercial power supplies designed for this sort of thing produce
13.8 volts. This is approx the voltage with the engine running in a
car with 12 volt electrics. 12 volts equates to a nearly flat
battery - and your rig may not perform correctly with this.


Whilst Dave is correct it did not answer your question !

The reason being there's not much point in using an available power supply
if it doesn't do the job properly. Of course it may be ok - but then you
don't know this anymore than I do.

--
*I wished the buck stopped here, as I could use a few*

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

In article ,
Baron wrote:
Dave Plowman (News) wrote:

In article
,
wrote:
I have a mobile ham radio that I would like to use as a fixed
station in my home. As this is a non-standard use of the radio, I
have found a possible solution in the way of an external Dell
Optiplex AC/DC Power Supply that should provide the necessary
voltage (12v) and amperage (12a) to power it.

My question is... In the adapter that I am creating, is it necessary
to use all three of the positive voltage pins (i.e., #2, #3, #4) from
the Optiplex Power Supply and all three of the negative grounding
pins (i.e., #6, #7, #8) to supply voltage to the single positive
voltage pin and the single negative grounding pin of the ham radio?
Or should it only be necessary to use one positive voltage and one
negative grounding pin to connect to the 2-pin ham radio?

Most commercial power supplies designed for this sort of thing
produce 13.8 volts. This is approx the voltage with the engine
running in a car with 12 volt electrics. 12 volts equates to a
nearly flat battery - and your rig may not perform correctly with
this.


Whilst Dave is correct it did not answer your question !

The reason being there's not much point in using an available power
supply if it doesn't do the job properly. Of course it may be ok - but
then you don't know this anymore than I do.


I never intimated that I did ! I answered the question the OP asked,
without making any assumptions.

Gary should be applauded for his Ham sprit by utilising equipment that
may otherwise be laid idle. As far as doing the job properly is
concerned, surely that decision is up to Gary.

73's

--
Best Regards:
Baron.

On May 24, 11:10 am, Baron
wrote:
Whilst Dave is correct it did not answer your question ! All the
positives will be connected together as will all the negatives. The
reason that there are three pins in the plug for each rail is that the
current rating of each pin is only 4 amps.

Each pin only being rated for 4 amps sort of makes sense. However,
the total amperage output of the Optiplex Power Supply is 18 amps,
which would cause me to assume that the amperage across each pin must
be 6 amps (18amps/3pins), though I don't have an ampometer to confirm.

This might actually work in my favor, since the ham radio is rated for
12 amps input and I could just use two of the pairs to supply it. Or
would it be better to push the total 18 amps to the radio?

Again, this is all contingent on the ham radio working on the flat 12
volts instead of 13.8 volts.

Thank you both for your comments.

Kind Regards,


Gary

On Sun, 24 May 2009 14:46:43 -0700 (PDT),
wrote:

On May 24, 11:10 am, Baron
wrote:
Whilst Dave is correct it did not answer your question ! All the
positives will be connected together as will all the negatives. The
reason that there are three pins in the plug for each rail is that the
current rating of each pin is only 4 amps.

Each pin only being rated for 4 amps sort of makes sense. However,
the total amperage output of the Optiplex Power Supply is 18 amps,
which would cause me to assume that the amperage across each pin must
be 6 amps (18amps/3pins), though I don't have an ampometer to confirm.

This might actually work in my favor, since the ham radio is rated for
12 amps input and I could just use two of the pairs to supply it. Or
would it be better to push the total 18 amps to the radio?

Again, this is all contingent on the ham radio working on the flat 12
volts instead of 13.8 volts.

Thank you both for your comments.

Kind Regards,


Gary
Gary, there seems to be a common misconception on the significance of
voltage and current ratings on power sources (power supplies and
batteries) and power consuming devices (light bulbs, fans, and
transceivers). A properly regulated 12 Volt 18 Amp power supply (I
am reasonably confident the Optiplex meets that description) will
supply 12 volts at up to 18 amps. Hooking up a 12V 1 Amp load would
result in 1 amp at 12 volts being drawn from the power supply. The
additional 17 Amps are simply not produced by the power supply (unless
you hook up an additional load).

A mobile transceiver will be designed to work on a rather wide range
of voltage. The nominal voltage of a fully charged 12V lead-acid
battery is actually 12.6 volts. It's charging voltage is (the voltage
across the terminals of a car battery with the engine running) is 13.8
volts. Partially discharged the voltage can drop below 12 Volts. A
manufacturer would not want to design a transceiver that will stop
working when the battery is half discharged. (Now a desktop computer
with an external power supply would be another matter.) I would
expect the transceiver to work over a range of 11 volts to 15 volts.

Do use all 12V terminals and all ground terminals in your adapter.

PlainBill

On May 24, 7:27 pm, wrote:
Gary, there seems to be a common misconception on the significance of
voltage and current ratings on power sources (power supplies and
batteries) and power consuming devices (light bulbs, fans, and
transceivers). A properly regulated 12 Volt 18 Amp power supply (I
am reasonably confident the Optiplex meets that description) will
supply 12 volts at up to 18 amps. Hooking up a 12V 1 Amp load would
result in 1 amp at 12 volts being drawn from the power supply. The
additional 17 Amps are simply not produced by the power supply (unless
you hook up an additional load).

A mobile transceiver will be designed to work on a rather wide range
of voltage. The nominal voltage of a fully charged 12V lead-acid
battery is actually 12.6 volts. It's charging voltage is (the voltage
across the terminals of a car battery with the engine running) is 13.8
volts. Partially discharged the voltage can drop below 12 Volts. A
manufacturer would not want to design a transceiver that will stop
working when the battery is half discharged. (Now a desktop computer
with an external power supply would be another matter.) I would
expect the transceiver to work over a range of 11 volts to 15 volts.

Do use all 12V terminals and all ground terminals in your adapter.

PlainBill

PlainBill,

Thank you for your insightful explanation of the usage of volts and
amps in particular to my real-world application.

I will be sure to use all three pairs of 12V and ground terminals with
my adapter.

A big thank you to everyone who responded to this thread. This usenet
group provide the exact assistance I was hoping for.

Respectfully,


Gary

I wanted to let you guys know that the adapter turned out well. The
ham radio came online, immediately. I am even able to transmit at the
50W maximum rating. I ended up running the #2, #3, and #4 pins to the
12V side and the #5, #6, #7, and #8 pins to the ground side of the
radio.

Thanks, again, for everyone's assistance.

Kind Regards,


Gary

wrote:

I wanted to let you guys know that the adapter turned out well. The
ham radio came online, immediately. I am even able to transmit at the
50W maximum rating. I ended up running the #2, #3, and #4 pins to the
12V side and the #5, #6, #7, and #8 pins to the ground side of the
radio.

Thanks, again, for everyone's assistance.

Kind Regards,


Gary

Good for you ! I knew that you could do it !
73's

--
Best Regards:
Baron.