Bcd436hp gps

I just bought a Bcd436hp and a gps Bcd436hp gsp. when the gps is hooked up and running does the signals I receive for my scanner come from the rubber antenna on the radio or the gps? The reason I’m asking is I would like to locate my scanner in a different location lower than my dashboard...

The GPS device has its own antenna (usually). No worries on what you want to do.

The GPS puck incorporates its own antenna that is only for the GPS. The scanner's antenna is only for the scanner's comm reception. They can be completely separated (well, still connected by the wire).

Gps

So I can have my scanner down by seat and the gps on the dashboard and get good reception??

n1vzxn1vzx said:

So I can have my scanner down by seat and the gps on the dashboard and get good reception??

Click to expand...

A very short answer is Yes for the GPS signal.....

n1vzxn1vzx said:

So I can have my scanner down by seat and the gps on the dashboard and get good reception??

Click to expand...

In testing the GPS modules I install inside tbe 436, I've kept satellite lock with the scanner under the seat and the GPS antenna facing down into the floor. Current GPS receivers are remarkably good at keeping a satellite lock under adverse conditions. Putting the GPS receiver on the dash will work fine unless you are in a tunnel.

The thing to note is you are receiving two separate and distinct "things".

One is the GPS signals coming from satellites. The GPS device will need a clear view of the sky for best reception. Placement on the roof is best for those GPS devices (pretty rare) that have separate antennas. The majority of GPS devices have internal antennas and placement of the GPS device on the dash is the best interior choice. As noted above being in a tunnel or inside a car parking garage results in very poor or no GPS signal reception.

The other "thing" is the radio reception stuff for the scanner. That comes in on the scanner antenna. Whether or not you have a GPS device attached to the scanner is of no consequence here. The metal skin of the auto body will block the radio waves to a degree. For very strong signals, it won't matter. However for remote stations that metal skin may mean to difference between reception or no signal.

Human bodies also can absorb/block radio signals, so if you have people sitting in both seats, that could also impact a weaker signal.

If you are using a GPS device, that suggests to me that travel might be involved which in turn means weak signals along the way. When I'm traveling with a portable scanner, I give serious thought to a magnetic mount antenna on my vehicle roof and connect that to the scanner. I've gotten pretty good results when I do that.

I was assuming an external antenna for scanner stuff in my previous reply.

The scanner covers frequencies between 25-1300MHz. The frequency ranges most people monitor with their scanner are vertically polarized VHF (~130-170MHz), UHF (~400-512MHz) and 800 (~700-900MHz). So most scanner antennas are designed to cover those ranges, with varying degrees of success. GPS signals are circularly polarized 1575MHz, and typically a patch antenna about 1 inch square (ideally oriented flat and facing upward), is used to receive them. Different antenna designs are required because the frequency ranges are different, and the polarization of the signal is different.

If you have the scanner connected to an external antenna for normal scanner traffic, the scanner can be anywhere in the vehicle and reception will be good because the non-GPS antenna is outside the vehicle. If you're relying on the factory whip antenna for scanner reception, it will work poorly inside the vehicle, especially if the scanner is down between the seats away from windows, because the body of the vehicle will block most of the signal. GPS reception is often possible inside a vehicle because the wavelength is small enough to allow the signal to enter through a window, and bounce around inside the vehicle until it reaches the antenna. Lower frequencies with longer wavelengths (particularly VHF) have difficulty getting through windows, and an exterior antenna is more important for these signals.

So from an absolute noob to all this,if I were to purchase a GPS compatible scanner for traveling,I would need a GPS antenna AND a mobile antenna(for the best signal) ?