BCD436HP/BCD536HP: Strange GPS Behavior

[k1sah]

I’ve noticed some odd behavior with the GPS in my 536.

I have coordinates set perfectly to swap between two systems when I cross the county line, it works like a charm when headed northbound, exactly where I want it to, but headed southbound it doesn’t change systems at all. It stays on the wrong one indefinitely or until I select the correct one with its favorites key.

The other strange behavior is less concerning but still a little baffling. When I’m in the parking garage at work and the puck has no line of sight the scanner reverts back to system number one, when it should still be, and has been, on number two. Again… not concerning because once I’m back outside and can see the satellites it brings up the correct system. This might even be a condition within the firmware. Just a head scratcher.

GPS is standard Uniden and has a very good look at the sky unless it’s in the garage. I just can’t comprehend the anomaly between northbound and southbound.

Any insight is definitely appreciated.

 

[G7RUX]

That sounds very much like a software issue related to the detection of or settings for the conditions.

 

[RMason]

When I’m in the parking garage at work and the puck has no line of sight the scanner reverts back to system number one, when it should still be, and has been, on number two.

How are you turning the 536 off when you park in the garage? Are you using the power knob, or removing power?

 

[k1sah]

Removing power. On/off volume knob stays in the same position always…

Which brings up another issue I’d forgotten… if I try to drive the volume a little hotter on P25 systems the radio will emit loud static for a moment and then power cycle. I thought it might be a voltage issue… but when I threw the meter on it I get a solid 13.8v.

 

[RMason]

Removing power. On/off volume knob stays in the same position always…

Since you are not using the power knob, the 536 is not saving the last location (and other settings) when it is powered down. In this case, it is likely using the location that was saved the last time the power knob was used. If this annoys you, you may want to turn the 536 off/on while in the garage. This should save the garage's location - and cause it to use the garage's location until the gps locks.

 

[k1sah]

That makes sense for sure. I didn’t think about saving settings after shutdown. My last truck/install I had was connected directly to the battery so I had to power cycle manually each time.

 

[sfb88]

As far as the north, south issue; where is the GPS puck located? Could it be as simple as the car facing in a different direction and not getting a good satellite lock in one direction?

 

[nessnet]

"I have coordinates set perfectly to swap between two systems when I cross the county line....."

Please give more detail as to how you are accomplishing this?

I ask, because the only way to accurately do this is to have your favorite list(s) locations set using rectangles (vs the default circles) and your global range set to 0.

 

[k1sah]

GPS puck is just inside the front windshield. Trust me it gets a good look at the birds.

My global range is set to zero and very accurate rectangles drawn. I’m often surprised at exactly how perfectly the systems change when I cross the county line northbound. I can see your suggestion that the GPS lock may be a little altered headed in a different direction and not switch exactly where I want. But: northbound is perfect. Southbound never switches at all… even 5 miles into my rectangle boundary. It just simply won’t change at all headed southbound.

Weird, right? Or has all the RF I’ve taken over the years scrambled my brain?