Strange workshop problem

[Mario Lucchesi]

I know that this may not be place to ask this but it is too wierd so I just have to tell you guys.

It has been pretty cold here in MI. so I have been running my Big salamander kerosine heater in my shop to warm it up. Well it turns out that whenever I am running the heater I cannot get my satellite TV to work in the shop. I use it to listen to the Sirius Jazz radio channel. It says that there is a problem in the switch. My power for the building is off of a breaker back at the house and the satellite is running from the house also. They are buried in the ground. (far away from each other.

I have discovered that as soon as I unplug the heater the satellite TV starts to work. I can then plug the heater back on and all is fine. Strange.

[David Weaver]

It's aliens...watch out for the probes! :D

Sounds like plain old interference to me.

[Andrew Williams]

My first guesses would be...

1. RF noise from the salamander fan.
2. Induced line noise on the AC ground from the salamander.

try to get a battery powered AM radio and listen to it with the salamander on and off, see if it picks up a buzz. Use the antenna position to localize the field that is creating the buzz.

if it is line noise, it should also show up on other devices like analog tv screens. Some multimeters will give a reading from one probe touching the mounting screw of any wallplate. If it changes when the salamander is on/off, then I would suspect line noise.

to fix the line noise problem, put the sirius on an isolation transformer.

to fix the RF problem....not as easy. short of replacing the fan, you could construct a grounded metal box around the fan motor to block RF. You could move the sirius antenna outside, etc.

and also there could be
3. ?
4. ?
5. ?

etc


YMMV (by a lot)

[Ken Garlock]

Hi Mario.

After I made the post that follows, I got to thinking. Do you turn off all the power in the shop when you leave for the day??? It sounds like you do. Since you are a Dish Network user, every time the controller box is powered down, it has to reload its brains from scratch. Part of that reload is getting its authorization to operate (smart card) from the satellite. Before trying anything else, I would just start the satellite tv and let it run for a minute until you get a screen that indicates the controller has found a connection and is scanning the various transponders. Then I would start the heater. This shouldn't take more than a couple minutes.

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I think Andrew is on the right track. First I would try a surge suppressor on the radio power line. Get one that lists noise suppression as a feature in addition to surge suppression.

Second, If the above has little impact, I would get another surge suppressor for the heater.

In addition, check your equipment ground (green) for good contact with the metal of the heater. I would also check that the green wire is making good contact all the way back to the power panel. Electricians tend to just give the wires a quick twist and not pay much attention to the quality of the 'bare wire' equipment ground connection.

I would use the metal box only as a very last resort. The noise will run out of the the box along the power lines. To make the box a good RF suppressor, you will need some type of feed-through capacitors that filter the power at the point where the lines pass through the metal box. This is not a task for the average weekend electrician,IMO.

[Mario Lucchesi]

Thanks guys for the advice. I am hoping that it will warm up soon and I will not have to run the heater any more. It is not a major problem just odd.

I have a few line filters from phone systems that I removed and will try that.