Anyone with an XTL5000 ?

[OffRoaderX]

I've noticed that my XTL5000 brick gets pretty warm just sitting idle, hot when transmitting at low power, and VERY HOT even if transmitting at high power in short bursts..

Just curious if this is normal/if they all get this hot.. I realize the brick is mostly a giant heat sink, but this thing is getting really hot.

 

[marcspaz]

It's been more than a year since I used mine.  I do remember it gets hot, like I thought something was wrong.  The guy I got it from swore it was normal.  He has been a Fire/EMT truck builder, doing all the electronics.  He said there is a temp sensor and if it gets too hot, you get a warning on the head display.

 

I am going to be out for most of the day Saturday, but when I get home, I'll pull it out and run it full tilt for a few minutes.  I'll take a few temp reading with the IR thermometer so you have something to compare yours to.

[OffRoaderX]

9 hours ago, marcspaz said:

when I get home, I'll pull it out and run it full tilt for a few minutes.  I'll take a few temp reading with the IR thermometer so you have something to compare yours to.

Thank you.. let it sit idle for a few minutes and take a temp, then transmit 5-10 times on low-power and measure, then 5-10 times on high power.

I have to friends I talked to about this last night.. One says that his "gets kinda warm", the other says "it gets really hot" ... Both using their hands to measure.. So some actual data will be helpful.

[marcspaz]

 

This is what I got.  Have to be honest... it's hot, but it "feels" hotter.  LOL  The IR was a good idea.

 

5 min Standby = 71.5 (room temp)

10 min Low Pwr (30 sec on, 30 sec off) = 95.7

10 min Hi Pwr (30 sec on, 30 sec off) = 124.4

[Lscott]

Now that you did some measurements it would be a good idea to include this as part of a radio's review. The problem with hand held radios is the continuing reduction in size. Starting with with the older Motorola brick radios down to the tiny palm sized units which which have to dissipate the same power, the RF power stages haven't changed much in efficiency over the years. The smaller cases, including the radio's metal chassis, and the use of more plastic leaves less area for heat to radiate. These smaller radios have a tendency to heat-up/over-heat far quicker than the larger older designs.  There are stories where some users have destroyed their radio from using it at more that a tiny TX duty cycle. The cheaper radios don't have over-temp protection. That's one area where they save money and why they're so cheap.

[marcspaz]

3 hours ago, Lscott said:

some users have destroyed their radio from using it at more that a tiny TX duty cycle.

 

I was iffy about mentioning this, since it wasn't asked by Randy, but the last three 30 second transmissions on high power, the amp meter on my power supply was showing the radio current draw was starting to waiver.  It would dip about 2 amps and pop back up.  I was loosing confidence toward the end, but it survived.  LOL

 

[Lscott]

4 hours ago, marcspaz said:

 

I was iffy about mentioning this, since it wasn't asked by Randy, but the last three 30 second transmissions on high power, the amp meter on my power supply was showing the radio current draw was starting to waiver.  It would dip about 2 amps and pop back up.  I was loosing confidence toward the end, but it survived.  LOL

 

Yup. People forget that hand held radios were never intended for high duty cycle, long winded, communications. Some work better than others in that use case. I've used a few of the palm sized radios where after a few minutes of moderate TX they were getting "uncomfortable" to hold. In the winter time they would make great hand warmers.

[marcspaz]

The XTL5000 is a commercial mobile vhf/uhf radio that was used privately and by first responders. It's pretty sturdy and comfortably goes up to about 850MHz, depending on the version. It was discontinued about 10 years or so.

 

I really like it, especially because it can be remote mounted, but I have many other modern radio with a lot more features. So, like my icom 7000, it just sits in a drawer just waiting for the occasional test ride 

[WRKC935]

Yeah, they do run a bit warm.

Might be worth having a shop do a FULL alignment on it and make sure they do the PA bias alignment but I know those radios would get warm sitting on antenna doing nothing.

 

[OffRoaderX]

2 minutes ago, WRKC935 said:

Yeah, they do run a bit warm.

Might be worth having a shop do a FULL alignment on it and make sure they do the PA bias alignment but I know those radios would get warm sitting on antenna doing nothing.

 

Its just back from the shop with a full alignment and checkup, so that does not seem to be a factor.

[WRKC935]

1 minute ago, OffRoaderX said:

Its just back from the shop with a full alignment and checkup, so that does not seem to be a factor.

OK,  I might have missed that you said that.  They do tend to run warmer that you would expect them to, especially when they are dormant other than being powered on.

 

[marcspaz]

36 minutes ago, OffRoaderX said:

Its just back from the shop with a full alignment and checkup, so that does not seem to be a factor.

 

I'm curious if you had time to run some IR thermometer readings yet and how it compares to mine?

[OffRoaderX]

2 hours ago, marcspaz said:

 

I'm curious if you had time to run some IR thermometer readings yet and how it compares to mine?

I ain't got no fancy IR ther-mom-eater !

[KAF6045]

41 minutes ago, OffRoaderX said:

I ain't got no fancy IR ther-mom-eater !

They aren't that expensive (unless you're buying from a culinary shop ). Some medical thermometers (see your pharmacy) may have an "open use" mode covering a wider temp range.

[marcspaz]

1 hour ago, OffRoaderX said:

I ain't got no fancy IR ther-mom-eater !

 

 

I bought mine from Harbor Freight for $25 when I was building a custom trans cooler for my GT350. I figured it would be "close enough".  I compared it to my friend's thermometer that he used for his restaurant, and it was only 0.5⁰ lower on the reading of the pizza oven. I was happy to see that.

[OffRoaderX]

ok, I want to be cool so i'll order one.

[marcspaz]

Nice!

[OffRoaderX]

Ok here's my temps:

• Sitting idle/receiving only for 1 hr = 102F
• Transmitting at low power several times = 130F
• Transmitting at high power, multiple times over 10 minutes = 160F

So as I suspected mine is getting hot (more hot than yours).. Now that i have a fancy thermometer I'll measure my other 2 (one in each Jeep) and see how they run.

EDIT/Update:  I put a little fan near it (this is a base-installation) to move more air around it and now it's running at about 120 after transmitting at high-power for several minutes.

[WRUU653]

Just a thought on this, while comparing temps it may be helpful to include the ambiant temp of the rooms. This might help show the percentage that one is warmer than the other. Particularly if located in different climates. It may not apply here, just trying to help as someone who has done thermal testing of electrical panels, motors etc.

[marcspaz]

Wow... yes, Sir.  That is a bit hotter than mine.  Looking forward to how the mobiles compare.

 

The owner's manual says the high-side operating temperature is +60* C (140* F).  They have to expect the radio will get hotter than the environmental temp, but I can't find anything about it.  I have a friend or two who may know.  I'll ask around.

[tweiss3]

I have a handful of questions, because this may be related to a conversation I had two weekends ago when I had a handful of radio's and my repeater on a friend's bench for their final checks before being put into service.

marcspaz - which split is your XTL? 380-470 or 450-520? What frequency was your test done on? Ham or GMRS?

OffroaderX - which split is your XTL? 380-470 or 450-520? What frequency was your test done on? I am assuming GMRS?

The reason I ask is he runs TK-890H (450-480) which can be tuned down to the ham bands. He was finding he would burn one up every 6-8 months even when turned down to low power. He found that, even on the edge of the band (such as in the 380-470 split radio) that the efficiency of the final drops off terribly. While some of that wasted energy can be a fan, the control head, etc, most of it is wasted in heat (what you may be experiencing). He then added a large copper heat sync to each PA and the TX VCO, and hasn't had in issue in 5+ years. Without the copper heat sync, the power draw was indicating a roughly 20% efficiency, and after the cooling mods, he was able to tune them to get 45%+ efficiency. 

We plugged in my TK-8150 and checked the power output in GMRS, was 43W at high power. We then checked the current draw, and with this inline (Amazon) was seeing a 82W draw giving it a 52% efficiency, which is actually pretty good. 

The point being, the comparison in temperatures between units should consider bandsplit and frequency. Besides the fact that OffroaderX seems to have improved his situation with active airflow cooling, it might be worth the time to open the case and attach a chunk of copper or aluminum to the PA with some thermal compound.

[marcspaz]

Mine is an M20RM.  438MHz to 482MHz.  Testing on a dummy load on 460MHz.

 

We can always make them run cooler.  The question (I think) is if its broken or normal.

[tweiss3]

12 minutes ago, marcspaz said:

Mine is an M20RM.  438MHz to 482MHz.  Testing on a dummy load on 460MHz.

 

We can always make them run cooler.  The question (I think) is if its broken or normal.

Alright, so yours is closer to the band edge than the other one.

Specifications indicate operating temperature range to top out at 60 degrees Celsius (140F). His does exceed that, however, I believe they are designed with a 5/10/85 duty cycle, so I'm not sure its a fair comparison. I don't think his is operating abnormally, but it would be worth the time to crack open the radio and see if a heat sync jiggled loose. Also, wouldn't be a bad idea to hook up a meter and see power draw. If he is spiking a power draw, it would be cause to check out the insides.

[SteveShannon]

1 hour ago, marcspaz said:

Mine is an M20RM.  438MHz to 482MHz.  Testing on a dummy load on 460MHz.

 

We can always make them run cooler.  The question (I think) is if its broken or normal.

You said you’re testing on a dummy load.  Is Randy?  That could make a difference.  Reflected power causes heat also.

[marcspaz]

1 hour ago, tweiss3 said:

Alright, so yours is closer to the band edge than the other one.

Specifications indicate operating temperature range to top out at 60 degrees Celsius (140F). His does exceed that, however, I believe they are designed with a 5/10/85 duty cycle, so I'm not sure its a fair comparison. I don't think his is operating abnormally, but it would be worth the time to crack open the radio and see if a heat sync jiggled loose. Also, wouldn't be a bad idea to hook up a meter and see power draw. If he is spiking a power draw, it would be cause to check out the insides.

 

I ran mine at a 50% duty cycle for close to half an hour. Tried to stress it on purpose. 

 

1 minute ago, Sshannon said:

You said you’re testing on a dummy load.  Is Randy?  That could make a difference.  Reflected power causes heat also.

 

Good point. Hopefully he'll see this and let us know. I have a 300w dummy load that is good from DC to 500MHz.

[OffRoaderX]

This one (I have 3) is 380-470 - and I was transmitting on 467.700, so you're right, it's right up there at the edge.. Measured with the antenna with SWR of 1.02 ...