Bloody Computers!

General questions on scanning from 30 to 3000Mhz. Not sure what you can receive in your area? Here's the place to ask!

Moderator: yorky

Post Reply
Clontarf[X]
Posts: 122
Joined: Mon Mar 10, 2008 1:31 am
Location: UHF 16

Bloody Computers!

Post by Clontarf[X] »

Well, I posted earlier saying I had problems picking up FESA clearly. I also realised that I wasn't hearing any of the rx I normally do (Wilson Security, Karrinyup Security, Surf Lifesaving, Transperth Security e.t.c). Found out what the problem was...

My computer was blocking(???) almost all my frequencies! I moved both the unit and the various antennae away from my computer and VOILA! Crystal clear rx :D So I suppose this means what my old pa used to say was right, "you'll hear the most when you're in the middle of nowhere". So I suppose next time I should troubleshoot properly and turn everything off :P

Also found out my CPU fan causes a cartload of interference, as do most of the electrical things in this house.
Tyranus
Moderator
Moderator
Posts: 3746
Joined: Sun Feb 18, 2007 5:41 pm
Amateur callsign: VK6FWDH
Scanners and Receivers: UBC93XLT
Location: Helena Valley
Contact:

Re: Bloody Computers!

Post by Tyranus »

Powersupply could also be at fault, for causing interference.
Stirling SES
Team Leader (Stirling 53)
Vertical Rescue Team Member
K9 7 Support

VK6FWDH
ex-Darlington FB
WARSUG Demi-God I mean Mod
If stupidity got me into this mess, why can't it get me out.
Image
Bonez
Moderator
Moderator
Posts: 807
Joined: Sun Nov 20, 2005 5:37 pm
Location: Perth, WA

Re: Bloody Computers!

Post by Bonez »

Scanners are very sensitive... I quite often use mine while sitting at my computer desk at home (with the 3db "Scantenna") - I think that is what it's called, but it's esentially an upgraded version of the stock standard piles of junk that come in the box when you first buy your scanner :)

I even notice the difference when plugging in the charger, I get interference from that. Much better signal when running purely from batteries.

bonez
robbage
Moderator
Moderator
Posts: 2993
Joined: Sat Feb 09, 2008 10:06 am
Amateur callsign: VK6UFO_VK6RN
Scanners and Receivers:  
Scanners/receivers
Diamond Welz WS1000 wideband handheld
Radioshack Pro 28 handheld
Uniden UBC72XLT handheld
Uniden UBC73XLT handheld
Uniden UBC330CRS desktop

Two-way
Yaesu VX-3R 2m/70cm Ham TRX and wideband RX handheld
Yaesu FT-1802M 2m Ham TRX mobile x 2
Yaesu FT-7800R 2m/70cm Ham TRX and wide band RX mobile
Icom IC-208H 2m/70cm Ham TRX and wide band RX mobile
Icom IC-706MKIIG all-band all-mode Ham TRX mobile
Icom IC-V85 2m VHF Ham TRX handheld
Wouxun KG-UVD1P VHF/UHF wideband Ham TRX handheld
Wouxun KG-679P VHF wideband Ham TRX handheld
Wouxun KG-713 UHF wideband Ham TRX handheld
Location: Just on the border of your waking mind

Re: Bloody Computers!

Post by robbage »

Bonez wrote:I even notice the difference when plugging in the charger, I get interference from that. Much better signal when running purely from batteries
I get the same. The noise floor comes up quite a bit, but it isn't noticeable on strong signals.
I keep the radios and computers on opposite sides of the room. Low loss coax helps a lot.
Rob
OF78WD
 Amateur moderator
.
Arguing with a fool proves there are two
SOL
Posts: 21
Joined: Fri Dec 14, 2007 10:55 am
Location: Perth

Re: Bloody Computers!

Post by SOL »

The gretest joy in my radio listening was when I bought my LCD monitor. You just don't realise how much QRM a standard PC monitor produces. Try listening to HF with an ant any where near an old monitor and frustration will set in. :(
Sol
Noel Taylor
vk6hgr
Site Admin
Site Admin
Posts: 2610
Joined: Thu Feb 24, 2005 10:33 pm
Amateur callsign: VK6HGR
Scanners and Receivers: Various Yaesu, Kenwood, Tait, Simoco and Philips'
Location: Perth, Western Australia
Contact:

Re: Bloody Computers!

Post by vk6hgr »

SOL wrote:The gretest joy in my radio listening was when I bought my LCD monitor. You just don't realise how much QRM a standard PC monitor produces. Try listening to HF with an ant any where near an old monitor and frustration will set in. :(
Sol
Not to mention that even if you fix all your gear and put ferrite beads on everything there's always the bloke across the road with the ginormous plasma TV that leaks RFI right through the spectrum :(

I don't have a huge issue with PC interference even though I have 4 computers in the same room as the HF set. It's good to make sure all the steel panels are secured properly and ditch any of those fancy cases that have perspex windows in them - it's just another way for the RFI to leak out.
Gavin Rogers; VK6HGR
http://vk6hgr.ampr.org/
WARSUG forum administrator
Site and stream donations: https://www.paypal.me/vk6hgr
Clontarf[X]
Posts: 122
Joined: Mon Mar 10, 2008 1:31 am
Location: UHF 16

Re: Bloody Computers!

Post by Clontarf[X] »

Funny you should bump this post today, just turned the scanner back on after a little break, my fileserver (which sits in a solid-steel case made for underground mines) doesn't affect the scanner at all. But as soon as I turn on the desktop machine, all hell breaks loose :D

Might have to move my gear to the shed I think.
SOL
Posts: 21
Joined: Fri Dec 14, 2007 10:55 am
Location: Perth

Re: Bloody Computers!

Post by SOL »

Plasma TV's, certainly are a noise source :| Also found pool chlorinators to be a shocker, my old one used to generate interference on HF to VHF, had to set it to run at night.
Have a lap top and PC with the radios and don't suffer to badly with interference as a matter of fact my Winradio G303 sits inside my PC and my PCR-1500 plugs into the usb port, no problems.
Two other places I get interference from is from the ASDL router and power line insulators when they get dirty and moist.
In all, I'm getting pretty good reception considering I'm living in a built up area in the burbs.
A number of years ago I lived in Marrangaroo and the then ABC regional transmitters used to be that strong that the RF used to get into the mains and cause inter modulation on my receiver even with a short aerial. Put a monitor and an old computer into the equation and my hobby was destroyed. Gave up listening for many years.

Sol
Noel Taylor
Lino
Posts: 49
Joined: Sun Feb 11, 2007 6:54 am

Re: Bloody Computers!

Post by Lino »

Hi i use 2 computers in my radio shack over 20 receivers 2 hf transmitters 2 vhf/uhf tramsmitters and get no intereference at all.

Regards Lino.
dlcat1
150+ posts
150+ posts
Posts: 445
Joined: Sat Jan 17, 2009 12:54 pm
Location: Melbourne

Re: Bloody Computers!

Post by dlcat1 »

Slightly off topic, but has anyone know what type of interference, or induced? interference, you might expect off one of those big naval transmitters up near Exmouth?

Reason for asking, I heard some stories about the Belconnen Naval Radio Station and wondering if its an urban myth.
SOL
Posts: 21
Joined: Fri Dec 14, 2007 10:55 am
Location: Perth

Re: Bloody Computers!

Post by SOL »

Need to ask the residents that live under the ABC tower. 50kW gets into everything. :shock:
I mentioned in a previous post that I used to live in Marrangaoo and had to give up SWL because the RF from the ABC short wave regionals was imposing on to every dam thing. My communications receiver at the time would pick up interference on one band and you could chase it back by just flipping the band selector through the frequencies. Huge ammounts of intermodulation!! Even my portable radio would receive 6WF on 1440kHZ. Just gave up listening untill we moved.
Sitting near tower Zero would be pretty interesting I think. Not sure what wattage the beast would pump out but I bet it would be huge. Most modern receivers have a pretty low sensitivety (by design) below 1.8MHz because the signals in this region can be quite strong. Just imagine a VLF transmitter pumping out huge ammounts of RF :(
There was a video of someone holding a fluro tube near the tower and it was glowing... Who knows what other effects that could occur?
Bye
Noel Taylor
Post Reply