I am looking for a good used MP-1 Super Antenna for a
reasonable price. I am putting together a rapid-deployment station for disaster relief situations. I also need a carrying case that measures about 18"x12"x6", or something close to that. Can anybody help? 73, Mark Baugh W5EZY Grenada MS __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Hi all,
Some days ago I posted a message regarding the charging of NiMh battery's. I got only one reaction, so I guess many are wondering what is a good way! I decided to go for the experimental way and did the following: - Measure the supply voltage, we call that U1; - Measure the battery voltage in charged situation, we call that U2; - Take U1-U2 and devide that over the charging current you want to use. In case of my 2400 mA/h cells I decided for a "conservative" 200 mA; - The result is the resistor value, in my case about 33 Ohm; - Take the square of U1-U2 and devide over R and you have the power, in my case between one and 2W. I had a 33 Ohm resistor of 5W in stock which was only 0,3 inch, so it fits very nicely. I have mounted it on the component side of the pcb, otherwise it gets in the way of the battery! The result is very positive, it charges nicely. I have mounted a timer in line with the charging supply, an old Nokia 12V GSM supply, to avoid overcharging as I read that NiMh cells dont like that. Have fun! Oh and by the way; modifying is at your own risk and will probably violate the warranty. Or perhaps Wayne and Eric find it such a good idea that they will allow it ;) 73, Dick PA2DW _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
I for one would at least like to hear if someone see any remote problem with this type of mod?
KI4DGH Chuck > > From: "Dick Harms PA2DW" <[hidden email]> > Date: 2005/04/22 Fri PM 01:49:12 CDT > To: "'Elecraft Reflector'" <[hidden email]> > Subject: [Elecraft] KX1 battery > > Hi all, > > Some days ago I posted a message regarding the charging of NiMh battery's. I > got only one reaction, so I guess many are wondering what is a good way! I > decided to go for the experimental way and did the following: > - Measure the supply voltage, we call that U1; > - Measure the battery voltage in charged situation, we call that U2; > - Take U1-U2 and devide that over the charging current you want to use. In > case of my 2400 mA/h cells I decided for a "conservative" 200 mA; > - The result is the resistor value, in my case about 33 Ohm; > - Take the square of U1-U2 and devide over R and you have the power, in my > case between one and 2W. > I had a 33 Ohm resistor of 5W in stock which was only 0,3 inch, so it fits > very nicely. I have mounted it on the component side of the pcb, otherwise > it gets in the way of the battery! > > The result is very positive, it charges nicely. I have mounted a timer in > line with the charging supply, an old Nokia 12V GSM supply, to avoid > overcharging as I read that NiMh cells dont like that. > > Have fun! Oh and by the way; modifying is at your own risk and will probably > violate the warranty. Or perhaps Wayne and Eric find it such a good idea > that they will allow it ;) > > 73, Dick PA2DW > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
In reply to this post by DW Harms
In a message dated 22/04/05 19:50:27 GMT Daylight Time, [hidden email] writes: I had a 33 Ohm resistor of 5W in stock which was only 0,3 inch, so it fits very nicely. I have mounted it on the component side of the pcb, otherwise it gets in the way of the battery! The result is very positive, it charges nicely. I have mounted a timer in line with the charging supply, an old Nokia 12V GSM supply, to avoid overcharging as I read that NiMh cells dont like that. Reply: ----------------------------------------------- Hi Dick, Yes, that method will work and is used in most simple hand held radio battery chargers to limit the charge current. However to get the best life out of NiCad and NiMh cells/batteries I have always understood that they should be charged under constant current conditions at the recommended rate given with the cells or battery. The series resistor method does limit the maximum current though may partially fall down on not providing a constant current. There are several methods of providing a constant current, the most common being to use a voltage regulator with a series resistor providing feedback. I use an earlier method with two transistors and two resistors that is easily adapted to any required constant current and will cope with a wide range of input voltages. Not sure how the charging of the KX1 is configured so your options may be limited. Contact me off the list if you need the two transistor schematic. Gross Overcharging of *any* rechargeable cell/battery is always a problem resulting in heat generation and eventual destruction of the cells unless this is limited to a charge rate of 2.5% or less of battery capacity. I had something like 400 UHF HH to maintain at an oil terminal/gas plant and apart from the operators using the radios instead of a hammer, the main problem was gross overcharging which could lead to failure of the battery in as little time as a year. Some automatic chargers received more recently were the answer to this problem, though these are even today far from being widely available. Time limiting the charge will work as long as the battery is fully discharged to start with. A partly discharged battery subjected to a full charge cycle will only dissipate the resultant continuation of charge after full charge is reached as heat. Note that all modern cellular mobile telephones are fitted with an automatic charger to get maximum recharging life from the battery. Bob, G3VVT _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Hi Group,
This flag ship desktop microphone from Yaesu only sells USD255 in Hong Kong. I would be grateful if any of you could advise how good will it be if this mic is used with K2. Thank you in advance. 73 Johnny Siu VR2XMC _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Free forum by Nabble | Edit this page |