Hi Serge Also unplug all USB / screen / audio cables from the computer , boot up the PC and then plug them back in one at a time and see if any cause the noise level to increase. If they do wrap as many turns as possible of the offending cable around a big ferrite ring and try again I had to do this on USB to serial leads to get rid of crude on 2m 73's Dave G4IDR ------------------ -----Original Message----- From: "John Regnault" <john.regnault(a)btinternet.com> Sender: moon-net-bounces(a)mailman.pe1itr.com Date: Tue, 13 May 2014 15:09:32 To: <moon(a)moonbounce.info>fo>; <moon-net(a)mailman.pe1itr.com>om>; <Moon-Net(a)nlsa.com> Subject: Re: [Moon-Net] [Moon] COMPUTER NOISE _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html

Untitled DocumentHi Serge, It allot depends of PC power supply, but you can't influence on that (only with ferrite choke in some way), so you can't miss and improve your situation if you will connect your PC chassis with your radio station (receiver) ground (don't be chary regarding cross section of grounding cable (few mm2 should be OK)). Good luck, 73 de Branimir-9a9b ----- Original Message ----- From: serge To: José Angel Amador Fundora ; moon-net(a)mailman.pe1itr.com Sent: Tuesday, May 13, 2014 6:34 PM Subject: Re: [Moon-Net] COMPUTER NOISE Thanks Jose for the advise I ordered 9 ferrites from the US company. I am beaming east out to sea I could not understand what was going on. Now I know. Hope you are well & the family!!!! 73, Serge VE1KG ----- Original Message ----- From: José Angel Amador Fundora To: moon-net(a)mailman.pe1itr.com Cc: Serge Szpilfogel Sent: Tuesday, May 13, 2014 3:28 PM Subject: Re: [Moon-Net] COMPUTER NOISE Serge, Once I found that my PC PSU was not silent enough, RF wise.... when I opened to clean it up, the input choke had been substituted in China by two jumpers. I just grabbed the needed choke from another older AT (and better built) PSU and it seemingly was enough for curing discernible noise on HF. Nowadays my AGP video card went QRT and I just enabled the not so good on board video. The 18 MHz band now has noise from end to end. Pending solution.... You have been given good advices. Ferrites are your friends. Grounding the case helps. I use the third, ground pin properly on my station. Here it is usual to CUT the thick third pin on the power plug so it fits older flat blade power sockets. I neither fight it, nor follow them. I use both american and european sockets on my station, and the ground wire is connected properly on them all on my station (it is just not usal here, people tend to cut corners and the third pin). My present HF radio is using a switching PSU, which has two chokes in series, one filtering the RF coming in on the power cable and another stopping all the internal transients from reaching the power plug. And so far so good. 73, Jose, CO2JA El 13/05/2014 9:45, serge escribió: While I have no man made noise, in the last 2 weeks I noticed my Smeter going from barely S1 to S3 to S4. The culprit is my main computer. When turned off no problem. So what can I do about it??? will grounding the computer help?? This seriously affect my reception. My 10 years old laptop does not interfere or generate noise on the receiver. The main computer is window 7 & I guess the power supply may be the problem but I really do not know. Any suggestion would be helpful Serge VE1KG _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html 50 Aniversario de la Cujae. Inaugurada por Fidel el 2 de diciembre de 1964 http://cujae.edu.cu ------------------------------------------------------------------------------ _______________________________________________ Moon-Net posting and subscription instructions are at http://www.nlsa.com/nets/moon-net-help.html

Leif thank you for infos. I looked at your web site & I think I will start by using ferrites first. Putting the computer into a box is not on my agenda. I never had any problems until recently so I am trying to understand what has changed & WHY?. Also the noise on the receiver is not always there. I know it is the computer because once turned off everything is OK the Smeter falls back to S1 to S2. Most of the time on MAP65 the AUTO ZERO shows 19 or 20 when the noise is on we are talking 25 or 26 & I notice a degradation in the decoding. How about changing the PSU as someone suggested?? Next thing you know I will have to install Linrad!! for this I may have to fly you over hi!!! May be I should go back on CW & see how the real world is. No computer on hi!! Thank you Leif very much Serge VE1KG ----- Original Message ----- From: "Leif Asbrink" <leif(a)sm5bsz.com> To: <moon(a)moonbounce.info>fo>; <moon-net(a)mailman.pe1itr.com> Sent: Tuesday, May 13, 2014 10:04 PM Subject: Re: [Moon-Net] COMPUTER NOISE

Hi Bill What does this have to do with computer noise? hi Anyway, I would be very interested in any replies you get. I can tell you right now that you do not want the center pin to be loose. I can't speak to the plastic piece you refer to. I am preparing some AVA7 right now and was quite surprised to find the center conductor being significantly different than LDF7. It appears to me that Comscope (the new Andrew) is cutting corners and both inner and outer conductors are thinner gauge. Unfortunately I am not familiar with the RPC connectors but I see on the web that they are supposed to be compatible with both LDF7 and AVA7. I do not see anywhere on the web that older L7PNF, etc., connectors are compatible with AVA7, and that is what I am using. I have a variety of connector types, and I am finding that the solid, one-piece center conductor fits ok and can actually be cranked tight. That is what I plan to use. I see that you have to be very careful not to over tighten (or undertighten) due to the flimsiness of the material. I'm not real happy with this AVA7 stuff. Regarding the two piece version, the brass piece that 'screws' into the center conductor is EXTREMELY loose, but after snipping and bending tabs in and tightening the other piece against the tabs, things may tighten up ok. 73 Mike, KL6M BP51dc http://www.qsl.net/kl6m

To help with my connector issues I have uploaded some pictures of the connector. On the side of the connector is stamped ANDREW L7PDF-RPC. It is all one piece, in that it will not separate. The back piece does turn and will crimp around the cable. The cable is stamped Andrews AVA7-50 The problem is that the center conductor of the coax will not fit tight over the connectors center pin. And what about the plastic bit that was inside the connector center pin.... http://www.almaguin.com/eme -- Bill Booth VE3NXK Sundridge ON, Canada 79.23.37 W x 45.46.18 N FN05ns Visit my weather WebCam at http://www.almaguin.com/wxcurrent/weather.html Organ and Tissue Donation - The Gift of Life Talk to your family. Your decision can make a difference.