Max operating temps

[MountainmanTX]

I am fairly green with amateur radio. I have multiple radios, but aside from a couple bench mounted ones in my shack I have, all of them are HTs. I wanted to install a mobile unit in my car but I am wondering about max operating temps. Most radios I have seen have a max temp around 140F give or take. I drive a black car and live in central TX and today the internal temp of my car after work was 136F with windshield shade up and rear windows cracked, and it was only 100F outside. I am assuming I would need to wait for the car interior to cool off before use to avoid damage. Anyone have experience with radios not working when first getting in a car on a hot day? Or am I overthinking this?

 

[mmckenna]

I don't know about ham gear, but the commercial stuff will do just fine. The individual components are similar, and likely little difference between the amateur gear and commercial when looking at -most- tolerances.

I'm currently in Las Vegas. 103º, truck has been sitting outside for a couple of days. Kenwood LMR radio in it. Zero issues, and I'm sure the in cab temperature was well up around 130º at minimum with direct sun on the radio head.

After 30 years in the industry, I've never had any issue with any of our radios in high temperature climates.

So, good ham gear should be pretty similar. You might see some funkiness with the LCD display. I think you might be a bit more concerned than you need to be.

Long winded transmissions are usually a big heat generator, so if you are concerned, stay off the push to talk switch for a while. Mount the radio where there's some space around it and a bit of air flow.

 

[MountainmanTX]

I appreciate the info. I think I am going to go ahead with the install but I am going to put the main unit lower down near the floor vent so the A/C can cool it a bit before I start using it. I was mostly concerned with possible damage if the temp climbs above the max operating temp and sits there for a good while. I have a box of different sized high velocity fans in my shop from various computer builds over the years so I may upgrade the fan as well just to cover the bases.

 

[MTS2000des]

Keeping it away from direct sunlight will keep the temperature down. The last place you would ever want to mount a radio or control head is on the dash board, not to mention with airbags in most vehicles it can become a deadly projectile.

 

[mmckenna]

I am going to put the main unit lower down near the floor vent so the A/C can cool it a bit before I start using it.

OK. I think you are trying to over engineer this. Rare to see a commercial/public safety radio with a fan or installed with AC blowing on it. If the RF deck is mounted out of direct sunlight, I don't think you are going to have an issue. I'd be more concerned about the rapid temperature swings of having a radio in a hot car, and then suddenly blasting it with cold air. Rapid temperature cycles like that can sometimes cause more issues than they fix. Rapid heat/cold cycles may cause some damage to the circuit boards, traces and components with quick expansion/contraction.

 

[MTS2000des]

Most radio manufacturers advise NOT installing a radio directly near any type of vent. Putting it in a secure and safe location is what is ideal. Radio bricks for most LMR gear live in trunks which certainly aren't air conditioned but so long as there is 2 to 3" of space around the heat sink, the heat sink will do it's job. Like mmckenna said, you are over engineering it.

 

[mmckenna]

I am going to put the main unit lower down near the floor vent so the A/C can cool it a bit before I start using it.

Going to add something else here:

Be careful mounting radios on the floor/under the seat of a vehicle, especially if they have a fan.

There can be a lot of crud gather on the floors of cars, and a fan will suck that up.
Water/moisture/spilled beverages will also gather on the floor/under the seats, and the radio sitting right on top of all that will cause issues. I could tell you stories about having to deal with this….
Properly mounting them so they don't become projectiles in an accident is also an issue. You don't want to run screws through the floor.

It really is preferred to have them mounted up out of harms way with some airflow around them. Secure them well so they don't come loose in a collision/bumpy roads. Extra fans, A/C, etc, all overkill. I've worked on a lot of our PD vehicles that have 100 watt radios mounted in the drawer in the trunk/cargo area. No fans, no AC, just space for airflow. It's protected from damage and well secured so they don't come loose.

 

[k6cpo]

My club had some gear donated from an SK former member. In the stuff was a 6x6 inch scrap of silvered material that had been cut from on of those reflective windshield screens. I trimmed it to the size of the control head of my FTM-500 and velcroed it to the dash of my truck. Now my radio has it's own sunshield. The body of the radio is mounted under the driver's seat.

 

[n0xvz]

I drive a black car and live in central TX and today the internal temp of my car after work was 136F with windshield shade up and rear windows cracked, and it was only 100F outside.

I live in West Texas, where it's at least as hot...both outside and inside the vehicle. In my case, I drive a 2018 Ford F-250 and mounted the radio behind the rear bench seat. I have had no issues with heat, and I don't leave my windows cracked (hey, I don't need more dust in the truck!). From what I can tell, the radio gets plenty of circulation where it's located. Listen to @mmckenna. He gave me great advice when I did my install.

 

[Crazyhair]

Hello, I had a similar thread here.

This was my solution. Photo attached.

 

[GlobalNorth]

In my case, I drive a 2018 Ford F-250 and mounted the radio behind the rear bench seat. I have had no issues with heat, and I don't leave my windows cracked.

I have the same year and model of truck. My install was done the same way and I''ve never had an issue in the Arizona heat.

 

[kamaaina1]

Yeah, I just throw a heavy-duty / tactical handkerchief over the radio just to keep it out of direct sunlight.