Batboard

Hello all,

A quick question: I have my Syntor X9000 installed in the rear of my TrailBlazer, in an underfloor compartment. It doesn't have any REAL amount of airflow, but there is several inches of space around the top and sides of the transciever. I noticed today however, that the radio gets quite warm, hot even, but you can still hold it without being terribly uncomfortable (It's on RX all the time, TX only when vehicle is running). Currently, all it does is RX, as I have not had it programmed to my fire department frequencies, but I discovered that one of the freqs in it was my local Sherriff's Office (interesting listening). What would be an efficient way to cool the radio? How hot is too hot? I am merely looking for a cost-effective way to keep the radio within its operating parameters. Currently it just sits on the carpet, and I had pondered mounting it to a piece of sheet metal - figuring the carpet doesn't help dissipate much of the heat, and that the metal would work better. Any ideas are appreciated! Thanks!

--Chris

At a guess, I would say you are basiclly on the right track, as a piece of metal bolted to the radio should help dissapate the heat from the unit. Also, a couple of small fans (like the ones found in computer power supplies) mounted to the heatsink will probably make a noticeable difference as well. As far as how hot is too hot, I'm not sure, but I think there is a sensing circuit in the radio to reduce the power output if it gets to hot. If it doesn't, I'm sure about 20 people will have corrected me in about a day and a half .

FWIW, I checked the X9000 manuals specs pages. The only temperature reference related to Tx stability.

Lo Band 0.0005% of Ref Freq, -30C to +60C ambient, Ref 25C

VHF & UHF 0.0002% of Ref Freq, -30C to +60C ambient, Ref 30C

-30C=-22F; +60C=+140F; +25C=+77F; +30C=+86F

So they apparently can operate at a relatively high temp, but I would not advise it for very long. You might want to put a thermometer in there and see what you get after transmitting.

I think the computer fans may be a good idea.

Ken

Ken, use some spacers on the mounting bolts/screws to give the radio at least 1/2 to 1 inch air space between the radio and floor. That should be enough to have air flow arround the heatsink.
These radios were built to opperate in the trunk of police cars at full spec's.

Yes, they were designed for enclosed trunks, but it sounds as if this one is in a much smaller space. That could be a problem.

BUT!

You say it get uncomfortably (my word) warm just on receive? I have a Syntor X (non-9000) in the trunk of my car. It does not get warmer than ambient temperature ever under receive only conditions. And transmitting, the heat sink will warm up perceptibly, but certainly not uncomfortably even with long winded ham conversations. I have never detected it "hot" at all. And yes, it shows me about 135 watts on the Bird 43, so it's not loafing.

All that means I think there's some issue with your radio. I just can't see how it should get warm at all, never mind how you describe it, not transmitting. The above advice is good and should be followed for every installation, but that heating up on receive only sounds like cause for concern.

Good luck.

Well, as he says the radio gets warm during receive, my next question would be: does the vehicle have to be running for the unit to heat up? With it in an "underfloor compartment", I would say that it is very possible that the vehicle exhaust could be raising the temperature in the compartment that the radio is mounted in. I've never fooled with a Trailblazer, but I have seen many vehicles which have "hot spots" on the floor from the exhaust pipes.

The only time my x9k gets hot is when the sun has been hitting it all day. I've talked on it for two hours (rag chew..) and it never got hot.

wa2zdy - 135?!?? Wheeeee!

Okay, I mounted it to a piece of aluminum with about 1/2" of space between the transciever and the aluminum. I'll see how warm it is when I get home tomorrow afternoon.... that's generally when it's warmest, after having RX'd all day while sitting idle in my truck. I also have some pictures of the radio in it's compartment if anyone thinks that will shed some light on the situation...

--Chris