Lee,
What size wire are you using ? Should not be smaller than #12. The length should be as short as comfortably possible. That means as short as possible with enough extra length to dress the cable around the operation bench if/as needed, and to be able to pull the radio out of its operation position easily with out pulling the power cord out of the radio either on purpose or by accident. No need for any more length. Also, Be sure that the connections at the power supply terminals are solid. I used to work summers at a power supply house. They made very high current regulated power supplies for the military. There were instances where the customer would connect the test load to the PS with clip leads, and when the voltage at the load was out of spec, send it back. There was nothing wrong with the supply. The clip leads had too much resistance, and at the rated load, would drop too much voltage because of the bad connection at the PS terminals. Be sure your connections to the PS are clean and tight. Fuses should be mounted close to the supply, just like they are in your house. In the event of a short, you want to break the circuit before a fire starts. Present (currant?) thought says to fuse both leads. Use low loss auto blade type fuses. Other fuse holders can have a lot of resistance, and under load, drop the voltage. I have seen the cheap clip type de-solder a fuse cap ! You can get the auto blade holders with red and black leads at your local auto parts store to build your own, or buy them from Quicksilver Radio http://qsradio.com/index.htm or Powewerx all made up. http://www.powerwerx.com/fuses-circuit-protection/atc-inline-fuse-holder-ring-terminals-10-gauge.html 73, Gene K1NR On Fri, 9 Mar 2012 18:37:44 -0800 (PST) Lee Buller <[email protected]> wrote: > > I am rebuilding the power cord from my RM35M to the K3. > > Questions..... > > 1. Do you need fuses to be in both the positive and > negative lead? Or, since I > am a "fixed" station, can I get away with one fuse in the > positive lead? > Currently, I have both leads fused. > > 2. What length should the power cord be....considering > that there will be some > power consumption (voltage drop) in the line which is > longer than shorter? My > current length is over 6 feet. > > 3. Should the fuse(s) be mounted at the radio or at the > power supply? > Currently, mine are right at the power supply. > > The reason why I am rebuilding the power cord is that I > am getting somewhat of a > voltage drop on key down. According to the K3, the > voltage is at 13.8 but goes > to 11 volts at key down at 100 watts....around 21 to 22 > amps. So, I suspect > something might a tad glitchy in the power cord. Maybe I > just need to reinstall > the Anderson Power Poles. > > Comments? > > Lee - K0WA > > > > > In our day and age it seems that Common Sense is in > short supply. If you don't > have any Common Sense - get some Common Sense and use it. > If you can't find any > Common Sense, ask for help from somebody who has some > Common Sense. Is Common > Sense divine? > > Common Sense is the image of the Creator expressing > revealed truth in my mind. > - John W. (Kansas) > > Never interfere with anything that isn't bothering you. > ______________________________________________________________ > 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 --------------------------------------------------------------------- Web mail provided by NuNet, Inc. The Premier National provider. http://www.nni.com/ ______________________________________________________________ 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
