Blocking a marginal signal

ai4i

Member
Oct 22, 2008
61
2
8
69
Area Code 954
Embarrassed to admit, but after having XM for seven and a half years, I never thought about trying this. Parked in a marginal signal area, a friend walked over and put his hand over my micro-antenna and blocked the signal. I did not expect that a human hand would attenuate the signal enough to make it (the signal, not the hand) go away.
 

limegrass69

Confused
Oct 12, 2008
6,079
245
63
New York
At the frequency where Sirius and XM operate, the signal is not that tolerant of obstructions to begin with (it barely makes it through leaves on a tree). On top of that, the signal from the sats is not all that strong by the time it reaches the ground. So what you've described does not surprise me at all.

Now, tell your friend to move their hand so that you can start listening to the radio again!!
 

ai4i

Member
Oct 22, 2008
61
2
8
69
Area Code 954
He withdrew it, he is gone, his hand is fine. Every prior installation I have had has placed the antenna out of reach from the command post. This time, it had to be mounted near the top left corner of the windshield. I have found that it does not block strong signals such as those from nearby terrestrial repeaters.
 

HecticArt

Administrator
Oct 19, 2008
39,926
11,580
168
Toledo, Ohio
So your antenna is inside the car. If it's possible to find a spot outside on the roof or trunk lid, you should see your reception improve.

I don't know what you're driving, or how you have to have it set up to work for your situation, but if you can look at your signal strength meter with it set up the way you have it now, and then move the antenna to the roof, and look at the meter again, you might see an increase in reception.
 

ai4i

Member
Oct 22, 2008
61
2
8
69
Area Code 954
So your antenna is inside the car.
Where did you get that idea? The antenna is at the left front corner of the roof, which I described as being near the top left corner of the windshield. Perhaps I should have used the word, above. BTW...further experiments have shown that my hand will block even strong satellite signals, but the terrestrial signals punch right through.