Computer placement:

KO4IPV

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Is it true a computer cannot be paced near a exterior antenna ? My antenna is on rooftop up over inside wall of office is this a problem?
 

bharvey2

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Can your provide additional information? Is this a transmitting antenna or just receiving? What frequencies are involved in this antenna? How far away from the computer and what type of feedline is used? There are a lot of variables that can affect the answer to your question.
 

KO4IPV

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Can your provide additional information? Is this a transmitting antenna or just receiving? What frequencies are involved in this antenna? How far away from the computer and what type of feedline is used? There are a lot of variables that can affect the answer to your question.
It is a receiving antenna . A 100. - to 900 MHZ . Using MLR400 coax. About 25 feet straight down from roof antenna is a modem ( computer) on inside of home same wall
 

hiegtx

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Is it true a computer cannot be paced near a exterior antenna ? My antenna is on rooftop up over inside wall of office is this a problem?
It's not a rule that you cannot place these close together. Instead, it's really a suggestion since PCs, broadband modems, and printers (among other devices) can interfere with the scanner's operation. Many electronic devices do produce (usually) weak spurious signals at a number of frequencies. If one or more of these is on a frequency, or nearby, one of the programmed items on the scanner, it may interfere with what you can hear, or perhaps cause the scanner to stop and hold on a channel where there is actually no activity at that time.

Unless your PC or modem is extremely noisy, there likely would be no issue with an external antenna that far away from PC/modem. Signals from the exterior antenna would almost certainly be strong enough to override weak interference from something that far away, and using high quality coax also would isolate any interference received though proximity to the cable.

That being said, if your scanner itself is very close to a device producing interference, you might still get some effects from signals getting to the scanner itself, through the case. This would be more pronounced with a portable scanner connected to the antenna, as most have a plastic outer case. Desk/mobile scanners usually have a metal outer case, which helps isolate the scanner from unwanted signals.
 

KO4IPV

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It's not a rule that you cannot place these close together. Instead, it's really a suggestion since PCs, broadband modems, and printers (among other devices) can interfere with the scanner's operation. Many electronic devices do produce (usually) weak spurious signals at a number of frequencies. If one or more of these is on a frequency, or nearby, one of the programmed items on the scanner, it may interfere with what you can hear, or perhaps cause the scanner to stop and hold on a channel where there is actually no activity at that time.

Unless your PC or modem is extremely noisy, there likely would be no issue with an external antenna that far away from PC/modem. Signals from the exterior antenna would almost certainly be strong enough to override weak interference from something that far away, and using high quality coax also would isolate any interference received though proximity to the cable.

That being said, if your scanner itself is very close to a device producing interference, you might still get some effects from signals getting to the scanner itself, through the case. This would be more pronounced with a portable scanner connected to the antenna, as most have a plastic outer case. Desk/mobile scanners usually have a metal outer case, which helps isolate the scanner from unwanted signals.
Thankyou actually the scanner itself is much farther away from the modem, it is just the antenna 25 feet north of the modem I was concerned of, appreciation your advice I am assuming now that my situation is not a problem.
 

bharvey2

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Just for kicks, power down your modem and computer and run your scanner for a while. Power them back up and not any changes in either reception, noise, etc. If you don't notice a difference then I wouldn't worry about it.
 

n5ims

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I have a desktop PC that has a nice steel case and am using it for two of my indoor mag-mount antennas. These aren't my main station antenna but the ones I use when bad weather has me unplug my exterior antennas. I use them for both receiving and transmitting during weather nets. The only issue I have had is when I forget to reduce power to no more than mid power the PC will occasionally reboot when transmitting, but since it isn't my main PC this isn't a big deal. I have no noise on reception with this configuration.
 
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