Interference

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Phoenix805

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MIB - I finally remembered how to monitor the control channels (OK, so I looked it up!) and I had a little time. I pulled into the Fry's parking lot and listened to the CCs for simuls A, B, & G. The unused CCs were absolutely dead, no noise or interference. The 3 in-use CCs all sounded fine to me, no sign of interference. Maybe next week I'll pull into the AM-PM and park closer to the cell tower and see what happens.


<Quote:
Originally Posted by KB7MIB View Post
Wirelessly posted (Opera/9.80 (BREW; Opera Mini/6.0.3/27.2339; U; en) Presto/2.8.119 320X240 LG VN530)

(And reception of the RWC, or any 700/800 MHz frequencies is severely compromised by RFI in the area of 43rd and Northern. Possibly from the cell tower on the southeast corner. But that's another thread.)

I think you mentioned that before. Not to get too far off topic....I live just south of there and go through the intersection all the time and I've never experienced any interference. We've got to get together one of these days and compare scanners and interference and see what we can figure out.>
 

KB7MIB

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Do you have an attenuator on your scanner(s)? Try turning the attenuator on and off, and see if the "sound" of the active CC's changes.
On the unused CC's, was there any background noise, other than the normal rush of an open squelch, if you opened it up?
Did you notice any signal level, (any bars on the S-meter) without actual audio coming through?
Was reception of Glendale or Phoenix PD, or Phoenix FD (or any other users on Simulcast's A, B or G) the same as you normally hear them?
Maybe the problem has been cleaned up since I last tried listening to GPD there. I'm not scheduled to be the "security detail" for the Valentine's sales tent this week, as I have been the past half a dozen or so years, and I don't normally bring my PSR-500 to work otherwise. If I happen to have payday off, I usually have it with me when I pickup my paycheck, but that's about the only time I'm there outside of a scheduled shift.
 

KB7MIB

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Sitting in the Fry's lot right now, 9:50pm Friday. Using the analyze function on my PSR-500, I'm getting 4-5 bars of interference on the Simulcast G control channels (no 'S', just 4-5 bars). The active CC is about unmonitorable.
On the Simulcast B CC's, I've got 3-4 bars of interference on each, but can get something out of the active CC, albeit with lots of interference.
Simulcast A and the White Tanks IR are no better.
 

KB7MIB

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When I turned the attenuator on and off, I could hear the interference disappear and reappear. It's a high pitched whine. (No, I didn't even have the key in the ignition, so it wasn't coming from my car.)
The signal strength went from 5 bars without the attenuator, and 2 bars with, but the decode percentage went from 90+ with it on, to bouncing all over from 20- to 80-something with it off.
With the attenuator on, I could receive a little bit from Phoenix PD and FD. I didn't hear a peep from Glendale for the 20 minutes or so that I was listening.
 

Phoenix805

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NW Phoenix and NW Ohio
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Do you have an attenuator on your scanner(s)? Try turning the attenuator on and off, and see if the "sound" of the active CC's changes.
On the unused CC's, was there any background noise, other than the normal rush of an open squelch, if you opened it up?
Did you notice any signal level, (any bars on the S-meter) without actual audio coming through?
Was reception of Glendale or Phoenix PD, or Phoenix FD (or any other users on Simulcast's A, B or G) the same as you normally hear them?
Maybe the problem has been cleaned up since I last tried listening to GPD there. I'm not scheduled to be the "security detail" for the Valentine's sales tent this week, as I have been the past half a dozen or so years, and I don't normally bring my PSR-500 to work otherwise. If I happen to have payday off, I usually have it with me when I pickup my paycheck, but that's about the only time I'm there outside of a scheduled shift.
Wow, that's just weird. I'll have to try again. I was there about 2 weeks ago and it was dead quiet. I keep my attenuator on, that seems to help my reception, helps cut back other simulcast sites I suppose. There were NO bars on the unused control channels, and background open squelch noise sounded 'normal' to me.

I don't remember what the percentage rate was, but it didn't strike me as being low, I think I would have remembered that.

I'll have to try it again and play with the attenuator and specifically check for the things you mentioned.
 
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