|
Laptop SSB interference
I've just installed an ICOM 802 in my boat and today found that the only way
to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? TIA, Scott jsodellatgmail.com |
Laptop SSB interference
"scott" jsodellatgmail.com wrote in message
... I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? RF noise on HF frequencies need an antenna to be radiated and the antennae in this case are the power cords to and from the power brick. The power brick itself has to small dimensions to radiate sufficiently on HF. So all you need is to block the RF through the power cords. This can be done by running the cords through ferrite ring cores. Run each cord through a ring core, 10 loops or so. Ferrite clamps are mostly not so effective at HF, but more at VHF. You could try and find a radio ham in your neighborhood, they deal with these issues more often. Meindert |
Laptop SSB interference
On Wed, 30 Nov 2005 00:13:55 -0500, "scott" jsodellatgmail.com
wrote: I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. =================================== Are you running the power brick from a small inverter? If so, that is more likely to be the noise source in my experience. Try running the laptop on shore power while at a dock and see if you have the same problem. If not, consider getting a better inverter. My Xantrex Prosine generates very little RF noise compared to the small modified sine wave units. |
Laptop SSB interference
Quoting "Meindert Sprang"SNIP
Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? RF noise on HF frequencies need an antenna to be radiated and the antennae in this case are the power cords to and from the power brick. The power brick itself has to small dimensions to radiate sufficiently on HF. So all you need is to block the RF through the power cords. This can be done by running the cords through ferrite ring cores. Run each cord through a ring core, 10 loops or so. Ferrite clamps are mostly not so effective at HF, but more at VHF. You could try and find a radio ham in your neighborhood, they deal with these issues more often. Meindert Thanks, that's helpful. I got another suggestion off-list that shielding the brick in a grounded steel box might help but given the brick's small size I guess I will start with your ferrite sugesstion. Any suggestions on the best source for apppropriate ferrite ring cores? In browsing online cataologues this HF radio novice has found a bewildering variety of ferrite devices and materials. I agree that my next task is to find a local radio ham and get some hands-on help. Thanks, Scott |
Laptop SSB interference
Responding to Wayne B.
Are you running the power brick from a small inverter? No. At the moment It's hooked directly to shore power. In the past, while underway I've used a small Radio Shack inverter and you are correct, this is noisy enough to be a small problem with VHF. Have not tried it yet with the SSB. If so, that is more likely to be the noise source in my experience. Try running the laptop on shore power while at a dock and see if you have the same problem. If not, consider getting a better inverter. My Xantrex Prosine generates very little RF noise compared to the small modified sine wave units. I have a Xantrex 20A charger and yes, it is surprisingly quiet - can barely detect the difference between on & off when listening to the SSB. Scott |
Laptop SSB interference
Hello Scott,
I assume you can hear the interference on the SSB's speaker when the power brick is operating? I also assume the laptop is connected to the SSB via a serial port (or equivalently, to a TNC which in turn is connected to the SSB). If yes to both, try disconnecting the laptop from the SSB/TNC to see if you still hear the noise. If the noise goes away, then Meindert's suggestion may help. You can find clamp-on ferrites at Radio Shack. Use several turns per the instructions. It would be best to install at least one on the serial cable just before it connects to the SSB. Ideally, that would choke off any RF on the cable. If the noise is unaffected, the interference is probably being radiated. If you are using the laptop's internal soundcard, then the audio lines to and from the SSB should also have ferrite chokes. Running the laptop on internal batteries should completely solve the problem (while adding another, of course). Good luck. Chuck scott wrote: I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? TIA, Scott jsodellatgmail.com |
Laptop SSB interference
"scott" jsodellatgmail.com wrote in message
... Thanks, that's helpful. I forgot to mention that the ferrites are to be placed on the power brick side of each cable. Another one on the laptop side would surpress any interference out of the laptop's internal switchers. I got another suggestion off-list that shielding the brick in a grounded steel box might help but given the brick's small size I guess I will start with your ferrite sugesstion. Shielding the box only prevents interference from leaving the box by radiation, and this will, given the small size of the box, only be in the VHF-UHF range. HF interference is *always* transferred out of the box by conduction through a cable. If you check the FCC/CE standards about radiation limits, you will see that below 30MHz, only limits are given for conducted emission. Any suggestions on the best source for apppropriate ferrite ring cores? In browsing online cataologues this HF radio novice has found a bewildering variety of ferrite devices and materials. I agree that my next task is to find a local radio ham and get some hands-on help. Best bet indeed. Ferrites are specified for certain frequency ranges, so you have to pick the right type here. I'm afraid I can't give you the exact type from the top of my head, but 4C6 material comes to mind. Regards, Meindert |
Laptop SSB interference
Thanks for the good advice, comments below
"chuck" wrote in message ink.net... Hello Scott, I assume you can hear the interference on the SSB's speaker when the power brick is operating? Yes, but only when it is plugged into the laptop I also assume the laptop is connected to the SSB via a serial port (or equivalently, to a TNC which in turn is connected to the SSB). No, not from the tranceiver serial port, but directly from the ICOM 802's control panel headphone jack to the laptop soundcard's mike input via a mono audio cable. If yes to both, try disconnecting the laptop from the SSB/TNC to see if you still hear the noise. The interference stops if I unplug the brick's lead to the laptop, even if the brick is still plugged in to shoreside power. If the noise goes away, then Meindert's suggestion may help. You can find clamp-on ferrites at Radio Shack. Use several turns per the instructions. It would be best to install at least one on the serial cable just before it connects to the SSB. Ideally, that would choke off any RF on the cable. If the noise is unaffected, the interference is probably being radiated. If you are using the laptop's internal soundcard, then the audio lines to and from the SSB should also have ferrite chokes. I guess my next step is to try ferrites on the audio line. . Running the laptop on internal batteries should completely solve the problem (while adding another, of course). Yes to both, thanks Scott snip |
Laptop SSB interference
On Wed, 30 Nov 2005 12:52:51 -0500, "scott" jsodellatgmail.com
wrote: I guess my next step is to try ferrites on the audio line. . And on the output side of the brick. Gary Jensen at Dock Side Radio has a source for clamp on ferrites: http://docksideradio.com/ He is very knowledgable regarding the ICOM802 and noise issues. |
Laptop SSB interference
"scott" jsodellatgmail.com wrote in message ... I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? TIA, Scott jsodellatgmail.com From: "Lynn Coffelt" Subject: Laptop SSB interference Date: Wednesday, November 30, 2005 11:21 PM "scott" jsodellatgmail.com wrote in message ... I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? TIA, Gosh, I'm really hoping you let us know what results you have with the clamp-on chokes. I tried, without success, in helping several customers with similar power supply noises. I was going to suggest soaking the "power brick" for about 72 hours in salt water. Just hanging over the side works. Sorry, I know you are serious, but I have a "thing" about power bricks. Please let us know what happens! Lynn, Marine Electronics Expert |
Laptop SSB interference
Thanks; It's comforting to know that others share my pain! I can see that
there is likely no quick fix to the noisy brick problem, but if ferrites don't work maybe cobbling up some sort of Faraday cage will help. Probably this will not get done all that soon but I will check back when I have any notable successes-- or failures to report. I got an off list reference to an excellent summary of related problems and fixes http://audiosystemsgroup.com/Ferrites-Ham.pdf Scott (Marine Electronics Non-expert) "Lynn Coffelt" wrote in message ... "scott" jsodellatgmail.com wrote in message ... I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? TIA, Scott jsodellatgmail.com From: "Lynn Coffelt" Subject: Laptop SSB interference Date: Wednesday, November 30, 2005 11:21 PM "scott" jsodellatgmail.com wrote in message ... I've just installed an ICOM 802 in my boat and today found that the only way to get clean noise-free weatherfax reception on my Sony VAIO laptop is to disconnect the "power brick" and run the laptop on batteries alone. There are some other interference sources, especially the radar, but the laptop is the most inconvenient problem at the moment. Any suggestions as to how to reduce or eliminate RF interference from a VAIO power brick? TIA, Gosh, I'm really hoping you let us know what results you have with the clamp-on chokes. I tried, without success, in helping several customers with similar power supply noises. I was going to suggest soaking the "power brick" for about 72 hours in salt water. Just hanging over the side works. Sorry, I know you are serious, but I have a "thing" about power bricks. Please let us know what happens! Lynn, Marine Electronics Expert |
Laptop SSB interference
In article ,
"Meindert Sprang" wrote: "scott" jsodellatgmail.com wrote in message ... Thanks, that's helpful. I forgot to mention that the ferrites are to be placed on the power brick side of each cable. Another one on the laptop side would surpress any interference out of the laptop's internal switchers. I got another suggestion off-list that shielding the brick in a grounded steel box might help but given the brick's small size I guess I will start with your ferrite sugesstion. Shielding the box only prevents interference from leaving the box by radiation, and this will, given the small size of the box, only be in the VHF-UHF range. HF interference is *always* transferred out of the box by conduction through a cable. If you check the FCC/CE standards about radiation limits, you will see that below 30MHz, only limits are given for conducted emission. Any suggestions on the best source for apppropriate ferrite ring cores? In browsing online cataologues this HF radio novice has found a bewildering variety of ferrite devices and materials. I agree that my next task is to find a local radio ham and get some hands-on help. Best bet indeed. Ferrites are specified for certain frequency ranges, so you have to pick the right type here. I'm afraid I can't give you the exact type from the top of my head, but 4C6 material comes to mind. Regards, Meindert All very good advice, BUT if one were to put the BRICK in a metal box, and bring the wires in/out of the box, with Feedthru Capacitors of say ..01uf, all that hash would stay inside the box where it belongs. Old School technology from way back...... Bruce in alaska -- add a 2 before @ |
Laptop SSB interference
"Bruce in Alaska" wrote in message
... All very good advice, BUT if one were to put the BRICK in a metal box, and bring the wires in/out of the box, with Feedthru Capacitors of say .01uf, all that hash would stay inside the box where it belongs. Old School technology from way back...... Correct. But much harder to accomplish. And it has the disadvantage that the power cord and the low voltage cord on the other side now form one large RF antenna while using ferrites, the entire string of wire is broken into smaller parts which inherently radiate less and also pick up less. It might even be that in the first case you end up with a huge susceptibility for RF from the SSB.... Shielding works, but it would involve shielding and grouding of every single part in the loop. If that is not possible, it is best to break the loop at as many places as possible. Meindert |
Laptop SSB interference
I got a response from a friend on the Bristol Channel Cutter list who uses a
DC to DC converter for his laptop. Sort of a Gordion Knot-cutting solution - why try to fix an inherently noisy brick if a quieter purpose-made device is obtainable. His was made by a "Ham in Florida" and is very quiet - but he can't find the address of the guy who makes them. Since my Vaio's brick output is 19.5V I guess a stepup tranformer has to be part of any 12V input converter. Any problems with this approach and any thoughts about who makes one? Scott "Meindert Sprang" wrote in message ... "Bruce in Alaska" wrote in message ... All very good advice, BUT if one were to put the BRICK in a metal box, and bring the wires in/out of the box, with Feedthru Capacitors of say .01uf, all that hash would stay inside the box where it belongs. Old School technology from way back...... Correct. But much harder to accomplish. And it has the disadvantage that the power cord and the low voltage cord on the other side now form one large RF antenna while using ferrites, the entire string of wire is broken into smaller parts which inherently radiate less and also pick up less. It might even be that in the first case you end up with a huge susceptibility for RF from the SSB.... Shielding works, but it would involve shielding and grouding of every single part in the loop. If that is not possible, it is best to break the loop at as many places as possible. Meindert |
Laptop SSB interference
http://lindelectronics.com/cgi-bin/store/shop.cgi/!ORDERID!/aaa/x/dbx_gen_aaa_mfgs/
"scott" jsodellatgmail.com wrote in message ... I got a response from a friend on the Bristol Channel Cutter list who uses a DC to DC converter for his laptop. Sort of a Gordion Knot-cutting solution - why try to fix an inherently noisy brick if a quieter purpose-made device is obtainable. His was made by a "Ham in Florida" and is very quiet - but he can't find the address of the guy who makes them. Since my Vaio's brick output is 19.5V I guess a stepup tranformer has to be part of any 12V input converter. Any problems with this approach and any thoughts about who makes one? Scott "Meindert Sprang" wrote in message ... "Bruce in Alaska" wrote in message ... All very good advice, BUT if one were to put the BRICK in a metal box, and bring the wires in/out of the box, with Feedthru Capacitors of say .01uf, all that hash would stay inside the box where it belongs. Old School technology from way back...... Correct. But much harder to accomplish. And it has the disadvantage that the power cord and the low voltage cord on the other side now form one large RF antenna while using ferrites, the entire string of wire is broken into smaller parts which inherently radiate less and also pick up less. It might even be that in the first case you end up with a huge susceptibility for RF from the SSB.... Shielding works, but it would involve shielding and grouding of every single part in the loop. If that is not possible, it is best to break the loop at as many places as possible. Meindert |
Laptop SSB interference
I have a 12v to 19v car laptop adaptor,(DC to DC) which was shop bought
for Eur40, (made in China). It turns ship's 12volt supply into a selectable voltage to suit a range of laptops. As it is onboard and I am not, I can't give precise detail now, but do a Google search for "Car laptop adaptor" and it will link to suppliers. This is more efficient as it saves energy by not having to use an inverter to go 12v to 115/230v to power the laptop's power brick. A win-win situation as it saves the inverter losses in addition to removal of another noise souce Noel |
Laptop SSB interference
I have a 12v to 19v car laptop adaptor,(DC to DC) which was shop bought
for Eur40, (made in China). It turns ship's 12volt supply into a selectable voltage to suit a range of laptops. As it is onboard and I am not, I can't give precise detail now, but do a Google search for "Car laptop adaptor" and it will link to suppliers. This is more efficient as it saves energy by not having to use an inverter to go 12v to 115/230v to power the laptop's power brick. A win-win situation as it saves the inverter losses in addition to removal of another noise souce. Nol |
Laptop SSB interference
Yes, this is what I finally decided to do - seems by far the most elegant
solution (though I did appreciate Lynn Coffelt's advice to try soaking the AC-DC brick in sea water for 72 hours). I've ordered a DC to DC airplane and automobile converter from Linde afdter following the link previously suggested by "Johnhh" http://lindelectronics.com/cgi-bin/store/shop.cgi/!ORDERID!/aaa/x/dbx_gen_aaa_mfgs/. Not cheap but said to have good RF filtering to comply with airplane regulations. Hope it works as advertised and will report back after I get and try it. Thanks. Scott "nollaigoc" wrote in message oups.com... I have a 12v to 19v car laptop adaptor,(DC to DC) which was shop bought for Eur40, (made in China). It turns ship's 12volt supply into a selectable voltage to suit a range of laptops. As it is onboard and I am not, I can't give precise detail now, but do a Google search for "Car laptop adaptor" and it will link to suppliers. This is more efficient as it saves energy by not having to use an inverter to go 12v to 115/230v to power the laptop's power brick. A win-win situation as it saves the inverter losses in addition to removal of another noise souce. Nol |
| All times are GMT +1. The time now is 01:13 AM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 BoatBanter.com