Re: [Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery
Hi to the group. I hope the group wasn't thinking my test conditions were my recommendations for running the KX3-KXPA100 station. I purposely set it up under marginal conditions to test the new software and originally to test the old software. The battery is over 4 years old and I may replace it this spring. There were 3 fuses in the circuit and the KX3 was getting it's power from the duel socket on the KXPA100. The old battery was several tenths of a volt lower than my newer battery although it definitely does not have a dead cell. I could solve much of the problem with the original software just by running the KX3 directly off the battery. A new battery would also help. My goal when camping is 6 db over 5 watts which is 20 watts or 10 db over 5 watts which is 50 watts. I ran at 100 watts on my dummy load to make the entire test as tough as possible. I run almost 100% CW when I am camping as even low power RTTY or PSK31 draws much more total currant from the battery then CW in an hour of operating. Fargo has two 50 KW broadcast stations in the area so I was not surprised when I tuned in a 5 KW station that was 230 miles from me that I had the interference problem with the 160 position. I was pleased that the NOR position still worked but having said that I can see myself using the 160 position when I camp in the north wood of Minnesota. Once again I appreciate these two new options and they are meant to be used with reasonable care. 73 Ken W0CZ w...@i29.net Sent from my iPad > On Jan 14, 2014, at 9:36 PM, Wayne Burdick wrote: > > Thanks for the report, Ken. > > At lower voltages, especially in voice modes, you should consider dialing > back power output to preserve the amplifier's "headroom." For example, if the > supply is dipping below 11 V, I back the power down to about 50 W, just to be > safe. This is only a 3-dB drop in power but it'll be a little easier on the > gear. For higher/lower voltages, adjust accordingly. > > Of course the amp and radio will protect themselves if, due to reduced > voltage, you exceed a threshold of current drain, temperature, or other > parameters. > > 73, > Wayne > N6KR > > >> On Jan 14, 2014, at 6:11 PM, Kenneth A Christiansen wrote: >> >> I brought up my old deep discharge battery and am extremely please with the >> way it now works with the KX3 and the KXPA100. The KX3 was going down to >> 10.7 volts at 100 watts with about .9 volts of cable voltage loss. My >> digital meter was going down to 11.6 volts at the battery… > > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery
On 1/14/2014 7:36 PM, Wayne Burdick wrote: At lower voltages, especially in voice modes, you should consider dialing back power output to preserve the amplifier's "headroom." For example, if the supply is dipping below 11 V, I would work on raising the battery voltage, and on reducing the IR drop in the wire. Wire is easy -- bigger, shorter. As to battery voltage -- what kind of shape is it in? How do you charge it? For many years, I've run everything on my operating desk, including the K3 and P3, from the biggest deep discharge battery that Costco sells, float-charging it with a little 10A supply that regulates to 13.8V. With that kind of setup, I rarely saw anything less than about 12.5VDC on the K3 voltmeter, and I never ran out of juice, even with heavy contesting. And batteries don't last forever. I've gotten 3-4 years from the setup I've described. BTW -- distortion (splatter, clicks) also increases as DC supply voltage falls, so you'll have a cleaner signal at full power with higher battery voltage. 73, Jim K9YC __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery
Thanks for the report, Ken. At lower voltages, especially in voice modes, you should consider dialing back power output to preserve the amplifier's "headroom." For example, if the supply is dipping below 11 V, I back the power down to about 50 W, just to be safe. This is only a 3-dB drop in power but it'll be a little easier on the gear. For higher/lower voltages, adjust accordingly. Of course the amp and radio will protect themselves if, due to reduced voltage, you exceed a threshold of current drain, temperature, or other parameters. 73, Wayne N6KR On Jan 14, 2014, at 6:11 PM, Kenneth A Christiansen wrote: > I brought up my old deep discharge battery and am extremely please with the > way it now works with the KX3 and the KXPA100. The KX3 was going down to 10.7 > volts at 100 watts with about .9 volts of cable voltage loss. My digital > meter was going down to 11.6 volts at the battery… __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery
Wayne and the group Thank you for the new KX3 experimental firmware. I downloaded it tonight and quickly decided in my city environment the NOR setting was better for listening to weak stations on the low end of the broadcast band as I was getting some type of interference from higher in the band with the 160 meter selection. I am glad we have the option to set it either way and I am still pleased as always with the ability to listen to the broadcast band for news when I am camping. I brought up my old deep discharge battery and am extremely please with the way it now works with the KX3 and the KXPA100. The KX3 was going down to 10.7 volts at 100 watts with about .9 volts of cable voltage loss. My digital meter was going down to 11.6 volts at the battery and after I transmitted a while the voltage started going back up which is typical of the discharge of a deep cycle battery. I maintained batteries for 35 years for the phone company and every year we ran a similar test on those big batteries. The KX3 and the KPA100 both were cool to the touch after a test on the dummy load sending CW for a long time. I know I am going to have a lot of nice contacts from my camper this summer. I feel it works as well or better than my K2/100 did and I used that in the camper for 12 years. Thanks again for the new firmware and hope to work many of you from my camper this summer. 73 Ken W0CZ w...@i29.net Sent from my iPad > On Jan 11, 2014, at 3:17 PM, Wayne Burdick wrote: > > Hi all, > > If you're powering the KX3 and a KXPA100 from the same large 12-V battery, > and you've had a problem with the KX3 dropping power from QRO levels to 5 W, > please contact me directly. I have an experimental firmware fix for this. > > This only applies if: > > - the KX3 is connected to the amp via the special control cable > > - MENU:PA MODE set to ON > > - the power control is set higher than 10 W > > In this case (with the amp in-line), there was a bug where a drop in supply > voltage to 11.0 V or lower would kick the KX3+amp into QRP mode (with the amp > bypassed). > > A key-down drop below 11 V is not unusual with a moderately depleted 12-V > battery running a QRO station. With the new firmware, the user can continue > to use the amp anyway, at some appropriate power level. Of course you > shouldn't try to get the full 100 W output in this case. For example, if the > voltage is in the 11-V range on key-down, I recommend not using more than > about 40-50 W. At 10 V (which isn't even safe to us with some 12-V > batteries), you're better off using QRP levels and setting PA MODE = OFF to > conserve battery power. > > 73, > Wayne > N6KR > > __ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
[Elecraft] KX3+KXPA100 operation improved when running from a 12-V battery
Hi all, If you're powering the KX3 and a KXPA100 from the same large 12-V battery, and you've had a problem with the KX3 dropping power from QRO levels to 5 W, please contact me directly. I have an experimental firmware fix for this. This only applies if: - the KX3 is connected to the amp via the special control cable - MENU:PA MODE set to ON - the power control is set higher than 10 W In this case (with the amp in-line), there was a bug where a drop in supply voltage to 11.0 V or lower would kick the KX3+amp into QRP mode (with the amp bypassed). A key-down drop below 11 V is not unusual with a moderately depleted 12-V battery running a QRO station. With the new firmware, the user can continue to use the amp anyway, at some appropriate power level. Of course you shouldn't try to get the full 100 W output in this case. For example, if the voltage is in the 11-V range on key-down, I recommend not using more than about 40-50 W. At 10 V (which isn't even safe to us with some 12-V batteries), you're better off using QRP levels and setting PA MODE = OFF to conserve battery power. 73, Wayne N6KR __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
