Batboard

I have 2 motorola xtl5000 uhf 45 watt remote mounts and after a few hours of idle time the radio pack gets warm. Is this normal for these radios..??

All the XTL mobiles I have ever played with get warm to the touch just in the idle mode doing their thing. There
is electronics inside that generate heat. You got to love the design like this in a top of the line radio when the
engineers never paid any attention to the little things like heat being generated in the receive mode.

I hope they did a better job in the APX7500 mobiles. Have one that I will be playing with here shortly. My guess
is that it too will be warm to the touch. It is in the same case size with some minor outside differences.

Jim

MINOS1701 wrote:I have 2 motorola xtl5000 uhf 45 watt remote mounts and after a few hours of idle time the radio pack gets warm. Is this normal for these radios..??

Thanks Jim for the quick reply. that answered my question. Yes for a list price of over 4000.00 big ones you would think they would have figured a way to keep it cool or put a little 5.00 fan it to cool it down. since its normal I guess i wont worry about it but installing the pack into an enclosed center console like in my ford truck could be bad since the heat would build up with no place to go

I would caution you on placing it there if you plan on using it for any long duration transmissions such as in the
ham service. If so, then you will want to flow some air over the heat sink fins.

Jim

MINOS1701 wrote:Thanks Jim for the quick reply. that answered my question. Yes for a list price of over 4000.00 big ones you would think they would have figured a way to keep it cool or put a little 5.00 fan it to cool it down. since its normal I guess i wont worry about it but installing the pack into an enclosed center console like in my ford truck could be bad since the heat would build up with no place to go

Seriously? You'd put a fan in the radio? Wow, what are the chances of that failing?

werdnuts wrote:Seriously? You'd put a fan in the radio? Wow, what are the chances of that failing?

Not much higher than the fans in the $5000 MW810 mobile computer?

Yeah, but the MW810 wasn't designed to be a dash-mount.

Multiply the idle current by the voltage, that is how many watts of heat will have to go *somewhere*. In the case of an XTL5000 it's around 10 watts. The only ways to make the radio run cooler is to either get the heat transferred to the surrounding environment better or reduce the standby current.

To get better heat transfer you'd need a more efficient heat sink, more airflow, or both. Better heat sinks take up more space and tend to have thinner fins which are more fragile. More airflow would likely mean a fan and the problems of noise/dust/failure that come with it, and if the radio is mounted in a closed space a fan is little help anyway. The reason they put them in the MW810 is because a computer generates so much heat a fan become a necessity.

Reducing the current draw would mean redesigning the circuitry to use less power while still doing it's job, such as running the display, backlights, synthesizers, receive, scan. When you're dealing with a radio full of microprocessors you're kind of limited to how low you can get the idle current without sacrificing performance or cost.

For what it's worth, I know of busy police departments with large numbers of XTLs mounted inside of consoles and the failure rate of the radios themselves has been extremely low.

I'm finding my XTL getting heated even when powered down. It's warm when on, but is it normal for it to be heating up when off?