Re: [Elecraft] (OT) - Power Supply for SGC-237
In the past I've used a SG-237, a SG-230, a CG-3000 and a MFJ-927 all remotely mounted and powered from switching power supplies in the ham station (Astrron SS-25, MFJ-4125 and most recently a SEC 1235) - using both external DC feeds and biasT feeds through the coax. Never any problems. Phil - AD5X __ 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] (OT) - Power Supply for SGC-237
Plus Astrons have excellent overvoltage protection. The only RFI-induced malfunction I've ever been able to induce in an Astron is to trip that protector. It's a crowbar circuit that shuts of the output completely if it detects an over-voltage (typically something close to 15 VDC) on the output of a 13.8V supply. I've seen them trip when running at a commercial mountain top repeater after a nearby lightning strike and in my shack when I don't have everything grounded and have an RF-rich environment feeding an end fed wire at a voltage loop so it makes my fluorescent desk light blink, Hi! In any case, no voltage above the crowbar limit ever got out of the supply and simply switching the supply off, then on again reset it. (Automatic reset circuits are often used on those mountain top units.) Ron AC7AC -Original Message- On 11/2/2010 4:54 PM, Bob Cunnings wrote: Analog or switching power supplies themselves are highly susceptible to RF. A few millivolts of RF in the power supply can create an instability which could lead to a catastrophic failure. We never recommend regulated or switching power supplies because no one can predict when RF is upsetting the power supply and all installations differ in characteristics. This doesn't make any sense to me. Astrons and many others have been widely used in ham stations for decades, and these are all regulated supplies. Some are switchers, some are not. Indeed, that vast majority of 12V power supplies used by hams, and by commercial radio systems are regulated supplies. Rather, I strongly suspect that someone at SGC has a huge blank spot in the areas of RFI, the bonding of DC power lines, and how that DC power is obtained to provide power for accessories. This is an issue that W4TV has had to address with his various interface products. 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] (OT) - Power Supply for SGC-237
I, too, used my Astron SS-30 and Samlec SEC1225 power supplies for years to direct feed (via the coax) my SG-230 without a single problem. I'm not sure that the warning you read was even in the manual for the SG-230 when I bought mine back in 1987. Terry, W0FM -Original Message- From: Phil Debbie Salas [mailto:dpsa...@tx.rr.com] Sent: Wednesday, November 03, 2010 7:47 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] (OT) - Power Supply for SGC-237 In the past I've used a SG-237, a SG-230, a CG-3000 and a MFJ-927 all remotely mounted and powered from switching power supplies in the ham station (Astrron SS-25, MFJ-4125 and most recently a SEC 1235) - using both external DC feeds and biasT feeds through the coax. Never any problems. Phil - AD5X __ 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] (OT) - Power Supply for SGC-237 - SGC's FINAL DETERMINATION
Look what just showed up in my email from SGC: After getting together with one of our other technicians and using your Astron RS-20M, He seems to think that particular power supply should be okay with the coupler. So I would use your Astron power supply that is connected to your radio for your power supply. Best regards, SGC Technical Support KD7QDR --- Stan Levandowski WB2LQF HF QRP CW -- Doing more with less for over 50 years! QCWA #35038 OOTC #4558 NAQCC #4740 SKCC #6488 FISTS #14992 __ 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] (OT) - Power Supply for SGC-237
SG-237 and SG-230 both on Astron RS-30 supply. No issues including operation of the power supply with in 8 feet of the antenna. 73 Gene K1NR On Wed, 3 Nov 2010 12:36:08 -0500 Terry Schieler terry.schie...@wirelessusa.com wrote: I, too, used my Astron SS-30 and Samlec SEC1225 power supplies for years to direct feed (via the coax) my SG-230 without a single problem. I'm not sure that the warning you read was even in the manual for the SG-230 when I bought mine back in 1987. Terry, W0FM -Original Message- From: Phil Debbie Salas [mailto:dpsa...@tx.rr.com] Sent: Wednesday, November 03, 2010 7:47 AM To: elecraft@mailman.qth.net Subject: Re: [Elecraft] (OT) - Power Supply for SGC-237 In the past I've used a SG-237, a SG-230, a CG-3000 and a MFJ-927 all remotely mounted and powered from switching power supplies in the ham station (Astrron SS-25, MFJ-4125 and most recently a SEC 1235) - using both external DC feeds and biasT feeds through the coax. Never any problems. Phil - AD5X __ 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 - 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: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] (OT) - Power Supply for SGC-237
On SCC's Installation FAQ page I see this explanation: Analog or switching power supplies themselves are highly susceptible to RF. A few millivolts of RF in the power supply can create an instability which could lead to a catastrophic failure. We never recommend regulated or switching power supplies because no one can predict when RF is upsetting the power supply and all installations differ in characteristics. http://www.sgcworld.com/smartinstallFAQ.html Perhaps they are talking about RF pickup on a long run of power cable between a coupler located at the antenna and the power supply in the shack?? Bob NW8L On Tue, Nov 2, 2010 at 5:13 PM, stan levandowski sjl...@optonline.net wrote: If there is any lister using the SGC-237 autocoupler, could you please tell me what power supply you are using for it? My coupler (backordered for two months - they are apparently very popular) is arriving on Friday and I just found out from an SGC tech's email that I am only supposed to use an UN-regulated power supply (but NOT a wall wart). So after buying a nice Astron RS-20M power supply for my new K2, I find out I can't use it to power the coupler because the coupler might destroy the Astron electronics according to SGC (no details as to how or why in the email). Unfortunately, SGC's policy is that all technical assistance is via email only so I can't have a phone conversation with anyone there (I already tried!). Thanks! Stan Levandowski WB2LQF QRP CW: Skill, not power! QCWA #35038 OOTC #4558 NAQCC #4740 SKCC #6488 FISTS #14992 __ 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] (OT) - Power Supply for SGC-237
Bob, I guess I missed this in the FAQ: Analog or switching power supplies themselves are highly susceptible to RF. A few millivolts of RF in the power supply can create an instability which could lead to a catastrophic failure. We never recommend regulated or switching power supplies because no one can predict when RF is upsetting the power supply and all installations differ in characteristics. I can definitely imagine my 20 foot combination coax/power supply line acting like an antenna. So now all I need is a recommendation for a small UNregulated 12VDC power supply that isn't a wall wart. Stan Levandowski WB2LQF HF QRP CW -- Doing more with less for over 50 years! QCWA #35038 OOTC #4558 NAQCC #4740 SKCC #6488 FISTS #14992 __ 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] (OT) - Power Supply for SGC-237
OK, folks -- I located a 12 volt DC, 4 amp, UNregulated power supply for $7.95. It's just the guts - I get to build it into a nice cabinet, put an on/off switch on it, a pilot light, supply my own jacks, etc..PERFECT FOR A HAM! Here's the link for anyone with a similar need: http://www.mpja.com/prodinfo.asp?number=17636+PS Stan Levandowski WB2LQF HF QRP CW -- Doing more with less for over 50 years! QCWA #35038 OOTC #4558 NAQCC #4740 SKCC #6488 FISTS #14992 __ 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] (OT) - Power Supply for SGC-237
Stan, For an unregulated supply, try this MPJA unit - http://www.mpja.com/prodinfo.asp?number=17636+PS - You will probably want an enclosure, so look in the left side of the webpage for Boxes and Cabinets. Or purchase a transformer, a bridge rectifier and a capacitor and build your own power supply. Another alternative is to use a 12 volt battery charger - just add a capacitor (or a battery) to the output. 73, Don W3FPR On 11/2/2010 8:19 PM, stan levandowski wrote: Bob, I guess I missed this in the FAQ: Analog or switching power supplies themselves are highly susceptible to RF. A few millivolts of RF in the power supply can create an instability which could lead to a catastrophic failure. We never recommend regulated or switching power supplies because no one can predict when RF is upsetting the power supply and all installations differ in characteristics. I can definitely imagine my 20 foot combination coax/power supply line acting like an antenna. So now all I need is a recommendation for a small UNregulated 12VDC power supply that isn't a wall wart. Stan Levandowski WB2LQF HF QRP CW -- Doing more with less for over 50 years! QCWA #35038 OOTC #4558 NAQCC #4740 SKCC #6488 FISTS #14992 __ 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] (OT) - Power Supply for SGC-237
On 11/2/2010 4:54 PM, Bob Cunnings wrote: Analog or switching power supplies themselves are highly susceptible to RF. A few millivolts of RF in the power supply can create an instability which could lead to a catastrophic failure. We never recommend regulated or switching power supplies because no one can predict when RF is upsetting the power supply and all installations differ in characteristics. This doesn't make any sense to me. Astrons and many others have been widely used in ham stations for decades, and these are all regulated supplies. Some are switchers, some are not. Indeed, that vast majority of 12V power supplies used by hams, and by commercial radio systems are regulated supplies. Rather, I strongly suspect that someone at SGC has a huge blank spot in the areas of RFI, the bonding of DC power lines, and how that DC power is obtained to provide power for accessories. This is an issue that W4TV has had to address with his various interface products. 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
