Re: Topband: WATCH OUT !!Did you get a new cable modem from Comcast? Arris Modem equal lots of QRM
Jameco continues to sell linear wall warts, if you want them new. best wishes, Nick VE7DXR At 05:26 24-10-14, you wrote: On 10/23/2014 3:33 PM, JC wrote: So watch out is you have Comcast cable modem, it is necessary to choke the cable and the AC cord with FT240 # 31. With this fix ,the noise dropped from s8 to s0 but still audible at Doug receiver. By now this should be Ham Radio 101 -- that is, assume that EVERYTHING with a digital clock, and EVERY switching power supply is a noise source, and be prepared to choke them using my RFI tutorial as a starting point. It's also a VERY good move to replace all switching power supplies with a linear supply, or even a linear supply float charging a battery. I'm doing exactly that with cable modem, WiFi Router, CATV box, Internet radio, etc. In most cities, it's possible to find linear wall warts at second hand stores for a buck or less, and I also buy them at ham flea markets. And all the gear in my shack (except for computers and power amp), run off my small solar system. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Topband: WATCH OUT !!Did you get a new cable modem from Comcast? Arris Modem equal lots of QRM
Hi guys I would like to share with you what NX4D just found out. Doug has experiencing a strong noise on top band for almost a year. He did try to find it everywhere, disconnected all appliances in the house and the noise was still roaring. For some coincidence Dug removed the cable from the modem and the noise quit. The issue is that the Arris modem has an internal battery to work without AC power and when you remove it from the AC line the modem is still generating noise and you can come up into a conclusion the modem is clean. It is not, actually there are several reports of RFI going on for several years and FCC is doing nothing to stop it. Here another source of information about that modem http://forums.comcast.com/t5/Voice-Service-and-Equipment/RFI-Caused-by-Arris -Modem/td-p/548591 Doug also found many complaints about Cisco Modems too, especially the switching supply wall warts. So watch out is you have Comcast cable modem, it is necessary to choke the cable and the AC cord with FT240 # 31. With this fix ,the noise dropped from s8 to s0 but still audible at Doug receiver. Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: WATCH OUT !!Did you get a new cable modem from Comcast? Arris Modem equal lots of QRM
What is the model number of the offending modem? Garry, NI6T On 10/23/2014 3:33 PM, JC wrote: Hi guys I would like to share with you what NX4D just found out. Doug has experiencing a strong noise on top band for almost a year. He did try to find it everywhere, disconnected all appliances in the house and the noise was still roaring. For some coincidence Dug removed the cable from the modem and the noise quit. The issue is that the Arris modem has an internal battery to work without AC power and when you remove it from the AC line the modem is still generating noise and you can come up into a conclusion the modem is clean. It is not, actually there are several reports of RFI going on for several years and FCC is doing nothing to stop it. Here another source of information about that modem http://forums.comcast.com/t5/Voice-Service-and-Equipment/RFI-Caused-by-Arris -Modem/td-p/548591 Doug also found many complaints about Cisco Modems too, especially the switching supply wall warts. So watch out is you have Comcast cable modem, it is necessary to choke the cable and the AC cord with FT240 # 31. With this fix ,the noise dropped from s8 to s0 but still audible at Doug receiver. Regards JC N4IS _ Topband Reflector Archives - http://www.contesting.com/_topband _ Topband Reflector Archives - http://www.contesting.com/_topband
Re: Topband: WATCH OUT !!Did you get a new cable modem from Comcast? Arris Modem equal lots of QRM
On 10/23/2014 3:33 PM, JC wrote: So watch out is you have Comcast cable modem, it is necessary to choke the cable and the AC cord with FT240 # 31. With this fix ,the noise dropped from s8 to s0 but still audible at Doug receiver. By now this should be Ham Radio 101 -- that is, assume that EVERYTHING with a digital clock, and EVERY switching power supply is a noise source, and be prepared to choke them using my RFI tutorial as a starting point. It's also a VERY good move to replace all switching power supplies with a linear supply, or even a linear supply float charging a battery. I'm doing exactly that with cable modem, WiFi Router, CATV box, Internet radio, etc. In most cities, it's possible to find linear wall warts at second hand stores for a buck or less, and I also buy them at ham flea markets. And all the gear in my shack (except for computers and power amp), run off my small solar system. 73, Jim K9YC _ Topband Reflector Archives - http://www.contesting.com/_topband
