Yes true. However seeing they way some hams configure their stations,
building or modifying and implementing a power supply with voltage
sensing, is of serious questionable nature. Likewise, in conditions
where power supplies are buried under the desk. One needs to see the
volt meter when the supply is first turned on to assure the voltage is
correct. And that should be done before the radio is turned on. Oh
I know about crowbar circuits, but if that $2.50 part fails it will
likely take out a $3000 radio. This just isn't smart.
Having worked with equipment that was supplied with 35 ft or 50 ft power
cables for loads of 20A to 30A at + & - 18 volts, I understand just a
wee bit about voltage sensing circuits and what makes them oscillate.
Just err on the safe side. And for ham radio, it likely is not
necessary to have or implement remote voltage sensing. Wire and
connectors are cheap. Use a shorter length of wire or larger gauge
wire. There's no likely component failure with this approach.
73
Bob, K4TAX
On 12/24/2019 8:25 PM, K9MA wrote:
Typically, there are small resistors at the power supply between the output and
sense terminals to prevent the voltage from rising if a sense wire opens up.
73,
Scott K9MA
----------
Scott Ellington
--- via iPad
On Dec 24, 2019, at 5:39 PM, Bob McGraw K4TAX <[email protected]> wrote:
Yes, but one screw-up on the remote sensing system and it will take advantage
of the voltage overhead on the pass transistors and likely wipe out every piece
of equipment. I strongly do not advise it. And you make a valid point
for NOT using remote sensing.
73
Bob, K4TAX
On 12/24/2019 3:22 PM, Jim Rhodes wrote:
I have thought about doing that. Just requires a 2 wire hookup with small
gauge wire. But I run all of my small items like the remoterig box, LP-pan
box, VHF/UHF rig and so forth off of the main supply and if I have a larger
than anticipated voltage drop on rig power cable the voltage on the other
tings could go fairly high. The power supply is a HB thing with at least a
50 amp capacity and plenty of voltage overhead before pass transistors.
(Used to run 2 HF rigs before downsizing.)
On Tue, Dec 24, 2019 at 2:25 PM Rose <[email protected]> wrote:
First, it would require some basic technical skill ... (;-)
73
K0PP
On Tue, Dec 24, 2019, 13:20 Karin Johnson <[email protected]>
wrote:
Why hasn't anyone used remote sensing at the radio voltage input?
As far as I know all of the Astron supplies don't have external sense
wiring. Many so called professional grade high current supplies provide
For external connection of the voltage sense back to the regulator chip.
I've toyed with this idea a bit but haven't had the time dig in to the
Astron supply I have. If this were implemented then one could maintain
13.8 volts or whatever you desired at the radio power supply inputs,
Regardless of the current draw.
Karin Anne Johnson K3UU
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[email protected]
This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [email protected]
