Help with signal interference - Computers & Internet

A snowy picture was a characteristic of the old VHF TV sets which were particularly sensitive to either poor signal strength, mains borne or airborne interference, second channel interference via "skip" or "ghosting" because of reflected signals being superimposed on the direct signal.

Modern digital TV is almost impervious to such nuisances and where there is a weak signal the picture doesn't dissolve into snow but either pixelates or completely fails. That leaves electrical interference as a strong possibility - this could be generated by a fault within the TV set, be airborne and received by the aerial or by some nearby unsuppressed appliance transmitting radio frequency interference along the power lines.

The FT-840 uses a die-cast RF power amp with thermally switched fan to ensure full power output (up to 100 watts). The digitally synthesized local signals ensure clean, low-noise transmitter output on all HF amateur band. There might be no AC line interference. it has strong Rf output. any AC line intersect does not affect its radio performance. Check and adjust RF power so to maintain proper output. some times more RF power generated at the output may cause interference. adjust Rf power..Even some unfiltered Noise getting the other end of the end may calso cause interference. Check for any Ripple voltages present at the output. Contact authorised service station for further Rectification. thank you shanth

The rear screen heater is a pure resistance being fed with direct current and normally will cause no radio interference as it does not vibrate or oscillate, though a loose or dirty connection or dirty switch could produce interference.

Some cars use the rear screen as a radio aerial and these are prone to producing radio interference, especially when trying to receive vertically polarised signals.
I tried this myself using a bi-fi rear screen aerial adaptor and was very disappointed with the results, the signal-to-noise ratio was appalling.

If your car uses the rear screen as an aerial there is likely to be a box of electrickery physically somewhere near the rear screen where the aerial cable originates. This box contains stuff to decouple the radio signals from the HRW circuit and will probably contain a signal amplifier.

The static you hear might just be a drastic reduction in signal strength rather than actual generated interference. You can do little else but to check the connections to and from the unit particularly the ground connections and check the voltages present on the related wiring. If no external faults are found it is likely the box of electrickery has failed.

Spending a while looking at dedicated forums might help further.

While clearing the cache and checking your network settings are excellent suggestions, if they DO NOT resolve the problem then it is likely you have a weak or bad connection to your Internet provider (either the cellural data link and/or the WiFi link). This can occur due to a weak or intermittent signal or due to strong signal interference. I suspect the latter because you seem to be able to connect easily (indicating at least a good initial signal), but then it abruptly drops. Interference can come from many sources (motors, microwave oven, competing radio signals, nearby electrical lines, or a neighbor's WiFi signal on the same frequency and channel, etc.) It can also be caused by other devices on your own network such as a satellite box, a printer, or a streaming device that also connects to your Internet provider's signal.

A simple way to troubleshoot WiFi interference is to look at other ambient signals. Download an app called WiFi Analyzer from the Google Playstore. Run the app and very slowly move around the areas where you access the Internet. All measurable ambient signals will be displayed, including your primary signal, with their channel and relative signal strength. If there are others that approach or surpass your primary signal on the same channel, then WiFi interference is a likely source of your problem. The fix: change your router's signal to another (unused) channel. This is done by entering the router's setup routine and modifying that setting (usually at an internal URL address at or similar to http://192.168.1.1 - the exact URL and directions are on the documentation that came with your router or on the manufacturer's website).

The WiFi Analyzer may well identify the problem. But it will not identify other local sources of interference nor a weak primary signal, such as mentioned above. But changing the router channel may still help.

Or, you may eventually need to invest in a better router (N or AC protocol, and dual frequency) and/or switch to another service provider with a stronger signal in your area.

All laptops must meet certain requirements for interference---about all you can do is move the laptop further away and or see if another laptop has the same issue.

The problem with inside aerilas is the signal strength of 70% contains noise as well. You could try using a higher gain aerial and the interference will be limited with a better signal.
Any electrical items can interfere with a poor signal.

Just to provide clarification regarding the IR remote control- unfortunately its the opposite. A brightly lit room can negatively affect the infrared signal the remote uses to transmit the signal from the remote to the receiver- additionally interference may also be caused by fluorescent lighting. Another recommendation regarding IR signal interference is to; power everything off but leave the receiver & your TV on. Then proceed by powering one component on at a time, then testing the remote after each component has successfully been turned on. This process will also help you determine if a component may be causing the interference. Hope this helps! -Kirstie DISH Network

Do you have DSL? If so make sure you have a DSL filter on the line to the fax otherwise the DSL signal will interfere with the fax data signal. The DSL signal might not perceptively interfere with voice transmission (though it is likely that it would) but will definitely interfere with data transmission from the fax.

The wireless signal is most likely your culprit. Wireless-B and Wireless-G signals operate at 2.4GHz frequency, which is the same that many cordless phones use.

Some wireless routers will allow you to change the channel that they broadcast on -- that might help your interference problem slightly, but it probably won't make it go away completely. Your best bet is to keep the cordless phone a good distance away from the computer and wireless router (if not in another room, at least on the other side of the room).

Hope that helps!

For normal operation, set this control to the center position.
This feature has several uses and can help receiver operation.
If a received signal is slightly off frequency, the Delta-Tune control can be used to òfine-tuneó your receiver. Fine tuning is accomplished by listening for a more readable signal at the speaker or by noting the Smeter reading when the Delta-Tune control is operated. Another use of this control is eliminating adjacent interference (bleed over from other channels). If an exceptionally high level signal from an adjacent channel is creating interference on the channel being used, the Delta-Tune can be used to minimize or eliminate the interference. Rotate the control until you obtain minimum adjacent channel interference. NOTE: Delta-Tune is operable only in the receive mode.

It doesn't actually help receive any better, just can help kinda like a clairifier.

Dean Pitts
Rollin CBs
Mt. Vernon, TX