New Power Supply
Locked
 
|
Hello friends:
I am using a Samlex SEC1223 with my K3. I have some "electric-noise" on low bands (80 and 40 meters) and i think it comes from the power supply. I have been reading other friends with the same problem. I want test another one. What is your recomendation? Thank's a lot. -- Rubén Navarro Huedo - EA5BZ http://www.palotes.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
Hi Ruben,
I have two Samlex SEC1223 PSU's, neither gives any "electric-noise". They are fitted with ferrite cores internally to remove interference. I believe that early models of these PSU's did not have have them. 73 Stewart G3RXQ On Tue, 02 Feb 2010 08:45:12 +0100, Ruben Navarro Huedo wrote: > Hello friends: > I am using a Samlex SEC1223 with my K3. > I have some "electric-noise" on low bands (80 and 40 meters) and i think > it comes from the power supply. I have been reading other friends with > the same problem. > I want test another one. > What is your recomendation? > > Thank's a lot. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Ruben Navarro Huedo-2
The one I have been using with my K3 for more than a year is an Alinco DM-340MV,its an analog PS with up to 35A,comes with meters for voltage and current,very stable an it produces no noise at all,its not swtching type,I chosed this one because most the ones in the market of switching design produce spikes that affect reception in all bands.
AD4C "For a refined ham it is compulsory to own a k3" --- On Tue, 2/2/10, Ruben Navarro Huedo <[hidden email]> wrote: From: Ruben Navarro Huedo <[hidden email]> Subject: [Elecraft] New Power Supply To: [hidden email] Date: Tuesday, February 2, 2010, 7:45 AM Hello friends: I am using a Samlex SEC1223 with my K3. I have some "electric-noise" on low bands (80 and 40 meters) and i think it comes from the power supply. I have been reading other friends with the same problem. I want test another one. What is your recomendation? Thank's a lot. -- Rubén Navarro Huedo - EA5BZ http://www.palotes.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Ruben Navarro Huedo-2
Hi Ruben,
I use samlex 1223's for many years, mainly on my expeditions and also with K3. You have to know that there are PS's made in BY which look exactly like the original 1223 but they have no output filtering and they have a different 12V connector. They do have a noise issue, particularly on 80m SSB band. I know that these were sold at the Friedrichshafen hamfest a few years ago. There is enough room behind the 12V connector to add some filtering inside. Noise issues can be fully cleared up. I can send U some photos, let me know if you need. Don't worry, 1223 noise issues can be fully cleared up. 73! zoli ha1ag It is also wise to add a varistor to protect your radio if the PS bites the dust. Ruben Navarro Huedo wrote: > Hello friends: > I am using a Samlex SEC1223 with my K3. > I have some "electric-noise" on low bands (80 and 40 meters) and i think > it comes from the power supply. I have been reading other friends with > the same problem. > I want test another one. > What is your recomendation? > > Thank's a lot. > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
|
|
In reply to this post by Ruben Navarro Huedo-2
On Feb 2, 2010, at 2:45 AM, Ruben Navarro Huedo wrote: > I am using a Samlex SEC1223 with my K3. > I have some "electric-noise" on low bands (80 and 40 meters) and i think > it comes from the power supply. I have been reading other friends with > the same problem. > I want test another one. > What is your recomendation? When I got my K2 back in 2001, I was using a linear power supply. A few years ago, that power supply died when the power transformer primary opened. I bought a Samlex 1223 supply to replace it. I was impressed with the size of the unit, and it had no trouble supplying my K2/100 to full output, even on 160m. However, I was disturbed to find numerous spurs were audible on my antennas on 160m. The loudest of these was near 1845 kHz, about an S7 on the K2 S-meter. Note that the location and strength of the spurs varies with supply load. First, you need to identify if it is the Samlex that is causing the noise. I did this by momentarily turning the supply off. The K2 (and K3) draw little current in receive, so you should have about 2 seconds of receive before the radio goes dead. If the noise moves away rapidly or disappears completely, it is likely the power supply. I would recommend you try to find the strongest noise source for the load you have while receiving. Note that these switching power supplies will shift the intensity and location of their birdies when the load changes. The SEC-1223 does not have a filtered AC cord. I used a snap-on toroid core to determine that the AC line could use some filtering. If your AC receptacle is already filtered, you can go directly to the DC output lines. I found that putting a snap-on ferrite core around the power cord reduced the spur to an S5 indication. A similar reduction could be had by placing a snap-on ferrite around the power output leads. My first modification was to de-solder the white and black power cord jumpers inside the unit in order to slip on seven FT50-77 toroids. After this modification, the spur was reduced to an S5 indication. Since that wasn't sufficient, I then made a modification similar to that designed by ZL2DF and published by N0SS: http://www.n0ss.net/samlex_1223_rfi_mods_from_zl2df.pdf My unit was different from ZL2DF, in that it did not have the screw / compression power terminals. Instead, my unit used two binding posts that were soldered directly to spade terminals on the PC board. After pulling out the PC board, I removed the spade terminals. I replaced these with 16 gauge wire fed through eight type 43 ferrite beads for each lead. The wire is small, but it is the largest that would fit through the beads. the output terminals are bypassed across each other and to chassis ground with .1 50v multi-layer ceramic caps. After this, the spur at 1845 kHz was just audible. At night, atmospheric noise covers it up. This supply was originally designed to work with VHF/ UHF gear, and likely does well. With minor modifications, it is suitable for use with HF gear. Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email] Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Snap-On Ferrites and RF Noise On 160M
|
|
On Sun, 18 Apr 2010 19:00:19 -0400, Bill Coleman wrote:
>I found that putting a snap-on ferrite core around the power cord reduced >the spur to an S5 indication. A similar reduction could be had by placing >snap-on ferrite around the power output leads. Study my tutorial on RFI and ferrites. http://audiosystemsgroup.com/RFI-Ham.pdf Most snap-on ferrites are designed for maximum effectiveness in the 150 MHz range. ANY "snap-on" ferrite is next to useless on 160M unless multiple turns are wound around it. If the wiring in question is radiating the trash as a common mode signal, you need enough turns around a ferrite core to place the very low-Q resonance of the ferrite choke near the frequency of the noise. This takes AT LEAST 10 turns through a relatively large #31 ferrite core. I've successfully used some moderately horrific cheap switchers in my ham shack by putting good chokes on both input and output cables, and by adding RF capacitors across both the AC line and the DC line. You can also suppress differential noise from SMALL levels of DC current with a choke on only one conductor. High levels of DC current will saturate a choke on only one conductor, but most of us don't worry a lot about RX noise when we're transmitting. :) Another point. It has LONG been known that twisted pair wiring minimizes the radiation and pickup of noise, yet we use parallel wire cable ("zip cord") for power wiring in our ham shacks. That's plain stupid if we care about noise and RF pickup! The problem is finding twisted pair cables of suitable size. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Snap-On Ferrites and RF Noise On 160M
|
|
It is not jacketed, but submersible water pump wire is often twisted
and in sizes as large as one could reasonably wish. Here is one example: http://www.deanbennett.com/submersible-pump-wire.htm David K0LUM At 9:37 AM -0700 4/19/10, Jim Brown wrote: > >Another point. It has LONG been known that twisted pair wiring minimizes >the radiation and pickup of noise, yet we use parallel wire cable ("zip >cord") for power wiring in our ham shacks. That's plain stupid if we care >about noise and RF pickup! The problem is finding twisted pair cables of >suitable size. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Snap-On Ferrites and RF Noise On 160M
|
|
Another solution is to take the "zip" cord and pull it apart, chuck two
ends in a variable speed drill and turn slowly, it will make a very nice twisted pair out of any guage. Just be sure to use a length longer than what you need as it looses length as it is twisted of course. To keep it in a tight twist I use small pieces of heat shrink spaced along the wires at intervals. I suppose one could use a piece of heat shrink over the entire wire if you wanted. YMMV 73 Merv KH7C > It is not jacketed, but submersible water pump wire is often twisted > and in sizes as large as one could reasonably wish. Here is one > example: > > http://www.deanbennett.com/submersible-pump-wire.htm > > David K0LUM > > At 9:37 AM -0700 4/19/10, Jim Brown wrote: > >> Another point. It has LONG been known that twisted pair wiring minimizes >> the radiation and pickup of noise, yet we use parallel wire cable ("zip >> cord") for power wiring in our ham shacks. That's plain stupid if we care >> about noise and RF pickup! The problem is finding twisted pair cables of >> suitable size. >> >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > 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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Snap-On Ferrites and RF Noise On 160M
|
|
In reply to this post by Jim Brown-10
On Apr 19, 2010, at 12:37 PM, Jim Brown wrote: > On Sun, 18 Apr 2010 19:00:19 -0400, Bill Coleman wrote: > >> I found that putting a snap-on ferrite core around the power cord reduced >> the spur to an S5 indication. A similar reduction could be had by placing > >> snap-on ferrite around the power output leads. > > Study my tutorial on RFI and ferrites. > > http://audiosystemsgroup.com/RFI-Ham.pdf > > Most snap-on ferrites are designed for maximum effectiveness in the 150 MHz > range. ANY "snap-on" ferrite is next to useless on 160M unless multiple > turns are wound around it. Please read the whole posting. The snap-on ferrite was used as a diagnostic tool. It showed a reduction in the unwanted signal on both the AC mains and the output power leads. Even if the snap-on ferrite was not the optimal final solution, it was useful in identifying where the energy was being radiated from the box. I did not use snap-on ferrites in my eventual solution to reduce the RFI. Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email] Web: http://boringhamradiopart.blogspot.com Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
«
Return to [HAM]
|
1 view|%1 views
| Free forum by Nabble | Edit this page |