Re: [digitalradio] I Hate Computers and Radio!!!! Interference. - Well I am Amazed - Update

[Gmail - Kevin, Natalia, Stacey Rochelle]

Hi All,

First of all THANKS to all those of you that replied with ideas and suggestions.

I have had a chance over the past couple of days to get into the computer and 
determined a few funnies.

1. When I removed the case lid and then replaced it I found the noise level had 
increases, so there is a bad ground between the two.
2. I placed a filter/conditioner in the mains supply, this improved the amount 
of noise and would be acceptable to use now, but there was still a small amount 
present.
3. I tried out my new(ish) laptop, an ASUS Core-2 CPU and found that there was 
no noise (if there was it was very low). However I like to run the 3 big 
monitors and monitor everything.
4. The monitors are not the cause of the noise, as I tested these by cycling 
them on/off.

Now that I have determined some things I might get it running on-air this 
weekend.
BTW, I have noticed that 7080 down in the South Pacific is mainly voice, have 
not heard too much digital. Might be able to sneak some WINMOR in. Will list 
when I am ready and on air.

Now back to the computer (desktop) and see if I can improve on it.

Regards

Kevin, ZL1KFM.

- Original Message - 
  From: Siegfried Jackstien 
  To: digitalradio@yahoogroups.com 
  Sent: Friday, September 25, 2009 4:38 AM
  Subject: AW: [digitalradio] I Hate Computers and Radio Interference.



  Hello kevin

  Is your hamshack and computer on the same power outlet??

  Try to use another outlet (maybe from next room with a long cable) :.

  Has the noise gone or become lower ???

  You can try to put a filter between the pc and the power outlet in the wall:.

  Can be built for a few bucks

  3 caps : a bifilar wound coil and a resistor is all you need :.

  If you are not a homebrewer these filters can be bought in almost any 
electronic store :.

  There are several on the market :.. (from 1A ═1phase to 60A 3phase)

  Try out the ps of your other pc :. You said it has lower power but for just 
trying out you can disconnect 2 of your 3 hd╢s

  And you can also unplug your cd-rom and/or floppydisk cause you don╢t need 
this for testing your rf noise problems

  If the noise is gone you have to talk with your wife (for the new ps) : grin 
:.

  I use a laptop for all my hamware :. The power that the pc needs is lower on 
a laptop/notebook

  They are optimized in the power consumtion for longer battery life :. Lower 
currents = lower noise

  The laptop has almost no internal wiring inside (just a few short cables) :. 
No wires = no noise from them

  But surely changing your pc is not the solution you are looking for 
:.═══ 

  Is the noise received in your antenna? (disconnect the antenna to check) :

  I have a very very light noise from my notebook ps (just s1-s2 with preamp on)

  If I move the ps around a bit I can find a place where the noise is almost 
gone :.

  So try out if changing the ps helps or build a inline filter :: that╢s the 
best I can tell about your problem

  Good luck in finding a solution for your rf noise

  Cu on the bands

  Best 73╢s de dg9bfc

  Sigi






  

RE: [digitalradio] I Hate Computers and Radio!!!! Interference.

[Michael Hatzakis Jr MD]

Hi Kevin, 

 

Truly a frustrating problem.  RF interference is one of the most maddening
problems hams encounter. suggestions, some art, some science

 

Get on e-bay and get some very long VGA extension cords, a wireless
mouse/keyboard or buy some very long extensions and move the PC 6-8 feet, or
more, away from the shack/antennas/coax.  RF fields decay at inverse log of
distance.  Since really, all of the motherboard and power supply designs are
essentially the same these days, you need to focus on case, in first
iterations of this.  

 

Go to Fry's or other similar stores and replace the PC case with a heavier
duty steel case, with fewer openings, which is the expense of $50-80 and the
effort of rebuilding the case.  But RF will come out of any wire or any open
hole. Ferrite beads make a small, but incremental difference on all cable
coming close to the hamshack.  In my case, the problem was the VGA cables
since there is a lot of switching of TTL coming through the cables, but,
unlike your situation, my noise got progressively worse when windows loaded.


 

Next, get online or local RF store and buy some very high quality coax
cable, LM-470 double shield cable or other very well shielded coax and
replace everything with it.  More expense of connectors etc. but worth the
expense.  Again, all your cables cannot use more than 20 feet of cable and
at $1-2/foot, not a huge expense

 

Obviously, just my opinions.  RF is an art form, not a science.  I am sure
others will have more scientific suggestions,

 

Michael K3MH

 

Michael Hatzakis, Jr MD
Physical Medicine and Rehabilitation

 

Owner and Medical Director
Rehabilitation Options of Issaquah
1495 NW Gilman Blvd Suite 4, Issaquah, WA, 98027 

 

Team approach to treatment of back and neck pain, sports and workplace
injuries

 

425-394-1200 Ph
425-394-0100 Fax
m...@hatzakis.net

 

http://www.rehabissaquah.com 

 

 

  _  

From: digitalradio@yahoogroups.com [mailto:digitalra...@yahoogroups.com] On
Behalf Of Gmail - Kevin, Natalia, Stacey  Rochelle
Sent: Wednesday, September 23, 2009 9:42 PM
To: digitalradio@yahoogroups.com; win...@yahoogroups.com
Subject: [digitalradio] I Hate Computers and Radio Interference.

 

  

HI All,

 

I have been trying for the past week to get my radio quiet from the computer
noise, WITHOUT any luck.

 

The computer is a ASUS P5B Deluxe P4-3Ghz w 2.5G of ram, and 3 H/Ds with
just under 1TB of space.

I have an onboard Sound-card, but I brought a SignaLink-USB which arrived
last week for digital modes.

I am running Win7 RC (far better then Vista and even lets me run 3
monitors(handy for HRD), which by the way are not causing the noise tested
them by switcvhing them on/off and did not interfer with the radio)

 

I believe the power supply in the case is causing the problem because when I
turn it on (before any software loads) the radio generates a S7 noise level
on 80 and 40, a little better on 20 and above, but still there.

Currently it's a waste of time even trying to listen for any digital traffic
on 7080, 14.070/112 a bit better. Was even going to try WINMOR, but from
what I have been reading I had better get the best RX I can first.

 

I have tried another computer and even though it did generate some noise
there, it was bareable with about an S2.

 

As of yet I have not tried another power supply as this would require me to
buy a new one (wife might get a bit upset about that one), I could pull one
out of a spare computer but it's not as big as the one I have.

I am about to do some googling to see if there is any mods on quieting the
RF from them.

 

Is there an easy; simple way to making this DAMM computer quieter Any
ideas would be a help.

 

Regards

 

Kevin, ZL1KFM.

 

It is coming in through the antenna because when I unscrew the coax from the
radio the noise disappears.