Re: [Elecraft] Power Suppy for K2
On 10/2/06, Samir Popaja <[EMAIL PROTECTED]> wrote: Which to choose, switching supply or not switching? I would say choose based on how you plan to use it. In a roomy radio work area a linear is nice and simple. It can also heat the room which is nice in Canadian winters. If you have a tiny area or will often move / carry the power supply you will likely want to choose a switching power supply. I personally have a 23A 13.8VDC Samlex model 1223. I've used it on both 120 and 220VAC with no problems. It requires an easy but many adjustment to switch input voltage so if you want to use it for international travel look for a model that works with any input AC voltage. Just about any will handle both 50 and 60 Hz with no issues. Whats the difference between switching supplies and not switching supplies? Pros and cons... The main factors are size/weight, efficiency, and RF noise. Switching power supplies are lighter and sizer for equivalent power output. Switching power supplies are more efficient at converting AC input to high current regulated DC output 80%-90%+ efficient versus about 30-60% efficiency for linear PS. This causes the amount of heat generated to vary based on the design type, the heat is a waste by-product of the inefficiency. Switching power supplies use a high frequency (20kHz - 2 MHz) in their conversion process, these can cause harmonic distortion in the RF frequency range unless properly filtered. I believe switching supplies will always raise the noise floor due to the nature of how they work, but I believe they can be filtered and shielded enough to make them usable in all but the most demanding to weak signal applications. I'm wondering that ELECRAFT hasn't devoloped PS to match design for K2 or K2/100? Three reasons I can think of are: A linear supply is boring design wise and very easy to home brew (as hard as a home brew QRP antenna tuner) and a large transformer needed to power the K2/100 is heavy to ship, and I suspect the economics were not attractive (Astron have the majority market share of the US amateur radio market). -Michael, VE3TIX ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
Re: [Elecraft] Power Suppy for K2
For the QRP K2, another good power option is an AGM lead-acid battery in 7 to 40 amp range, a multi-level charger (Battery Tender or Battery Tender Jr for the smaller batteries, Motorcycle Accesories Warehouse), and a 5-10W solar panel (EBay, Northern Tool) with Don Brown's controller for backup, all hooked together with Anderson Power Poles. You will be free of RF hash, and as a bonus can operate during power outages. 73, Leigh/WA5ZNU ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
RE: [Elecraft] Power Suppy for K2
I purchased a new ASTRON RS-35M, 35 amp 13.8VDC linear supply - for my ham, and K2 supply needs. It is more than enough amps, to supply all the current I may need from several pieces of ham gear. Astron supplies are built like tanks, and they hold their values over many years. I think the RS-35M was like $130 or $150 total, from HRO. Great supply, with amp and voltage meters too.IMHO - I'd stay away from any switcher supplies, no matter how ripple free they say they are. Noise is noise . Then when Elecraft comes out with their K3 in 2007 or 08 - I'll be set for that too! Fred N3CSY __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
RE: [Elecraft] Power Suppy for K2
For my K2, I went with the Astron RS-20M supply. It is a linear supply, not a switching supply. I went that way because I knew it would work, would generate no noise and would be something I could service down the road. I got the 20 amp supply even though my K2 is only 10 watts output. Someday, I'll have the 100 watt PA and then my PS will continue to work my K2. I believe Elecraft has not developed a PS because it is not cost effective to do so. There are people like Astron who specialize in power supplies. Elecraft would be hard pressed to come up with a better supply for the same price or a cheaper supply of equal quality. TenTec sells power supplies for their radios but as I understand, they are just Astron supplies with a TenTec logo. Even TenTec has quit designing their own supplies. - Keith KD1E - -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Samir Popaja Sent: Monday, October 02, 2006 5:15 AM To: elecraft@mailman.qth.net Subject: [Elecraft] Power Suppy for K2 Hello, Any recomendation for PS for K2? Which to choose, switching supply or not switching? Whats the difference between switching supplies and not switching supplies? Pros and cons... I'm wondering that ELECRAFT hasn't devoloped PS to match design for K2 or K2/100? Thanks ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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: Elecraft@mailman.qth.net 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] Power Suppy for K2
Hello, Any recomendation for PS for K2? Which to choose, switching supply or not switching? Whats the difference between switching supplies and not switching supplies? Pros and cons... I'm wondering that ELECRAFT hasn't devoloped PS to match design for K2 or K2/100? Thanks ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net 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
