Final temperature

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  • Question
  • Updated 4 months ago
  • Answered
  • (Edited)
I often run maximum power in Digital mode (FT8). Can this harm the final from my Flex 6500?
My DDutil temperature readings are 60 degrees celcius when i run maximum power.
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Geert Balsma PA3CPS

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Posted 2 years ago

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Bob Gerzoff, WK2Y

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Is the fan going into high speed?  
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Geert Balsma PA3CPS

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I don't no. My Flex is located in another room. But i can test that.  
(Edited)
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Mark WS7M

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don't take this as "the word" but I think the flex is pretty well protected if temp gets too high I believe things are shutdown.  Hopefully someone more knowledgeable will weigh in.

But to be sure I power limited my radio to 75 watts in the radio setup.

I also typically use my amp.  I set my flex to like 3 watts which drives my SPE 1K to about 175 watts.  

With my lousy antenna this probably works out to an ERP of like 50 watts (sigh)
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Ken - NM9P

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I run my 6500 at close to full power, (about 80 watts to make sure my signal is always clean) and with the 15 seconds on / 15 seconds off duty cycle, the rig hardly knows it is transmitting. I have not had the fan go to high speed,

On JT-65/JT-9, it is another story. It often hear the fan switch up to high after several QSO's in a row in those modes. Though the temp never seems to get excessively high.

Btw... your rack mount looks very clean, neat, and tidy.
As long as you have adequate ventilation.....

Ken - NM9P
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John KB4DU

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Ken;

I have tested my 6400 with a dummy load on FT8, calling CQ several times. The temp reported by FRstack reaches about 90C after several iterations, with the fan at high speed, but the temp seems to stabilize there with the 50% duty cycle at about 80 watts. Sometimes the power will reduce a little also.
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KC2QMA_John

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A better fan with more CFM's would sure help keep these temps down.
90C is very HOT 100C can boil water!!!

https://community.flexradio.com/flexradio/topics/6600m-fan-speed-questions
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Joe N3HEE

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Last weekend during the contests I found calling CQ (CQ TEST N3HEE N3HEE)every three seconds for five minutes or more on CW the PA would reach 60 C and stay there. The fan was ramped up on high. 

I also notice that even at idle the radio warms my air conditioned shack !  It is generating a lot of heat !
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KC2QMA_John

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Now imagine if you did not have your air conditioner on or were operating in an environment with a high ambient temperature like field day, mobile or just a hot shack.

https://community.flexradio.com/flexradio/topics/6600m-fan-speed-questions
(Edited)
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Joe N3HEE

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Yep, it would melt down !  I only noticed how warm it made my shack while it was in for service.  When I got the radio back and running 24/7 I noticed how warm the shack was getting.  It generates more heat than my computer.  The computer has two 400MM case fans one front and one rear, power supply has a large fan and the CPU has a fan.  The computer does not warm the room if the radio is turned off.
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KC2QMA_John

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You cant change the law of physics, When you transmit at 100W you are going to dissipate 100W of heat however with a good high quality fan with high CFM’s and RPM’s you can at least extract the heat out of the radio there for protecting the components and extending the overall life of the radio.

https://community.flexradio.com/flexradio/topics/6600m-fan-speed-questions
(Edited)
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Bob G W1GLV

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Why so much power, I''ve made plenty of contacts around the world at 15 watts maximum.
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Ken - NM9P

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Ft8 only copies reliable down to about -20 dB. If you are only -23 and go from 15 to 60 Watts, that is a 6 dB increase, taking you to -17 dB. The difference between a good contact and not being heard at all.
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Mark WS7M

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I use as little as possible.  I have run my amp with 1 watt out from the Flex.  That gives me about 40 watts created at the amp.  I have a pretty lousy antenna and I would figure with coax loss and antenna inefficiency that I am radiating (with 35 w from the amp) about 20 watts.

I usually start there.  If I am not heard I bump up 1 watt on the flex. At 2 watts I get 80 from the amp.  Again I figure ERP is about 50 perhaps. I keep working it up as I need to.

I find when I have the amp running about 80 W that I can get to almost anything on FT-8.  There are a few nodes on my antenna that I just can't overcome.

But keep in mind that JT65 and the other modes in that software are "weak signal" modes.  Not "low power" modes.  While it is always a great idea to use as little as possible there is nothing wrong with adding power to get the contact done.
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Chris DL5NAM

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..and lower signal from TRX into a amp will bring a cleaner signal out. ( here 3 Watt in gives me 2k out )
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NX6D Dave

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This question comes up regularly. The answer from Flex has always been 'no'. Processors in the radio watch voltages and temps and other parameters carefully and will shut down the radio if damage would be done by continuing.
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NX6D Dave

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The cooling fans going to high speed are an indication that the monitoring systems are working. 
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KC2QMA_John

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To my knowledge the 63/65/6700 are 100% duty cycle or close to it. The P.A is designed to be able to cool under full load. That being said if you were to place the radio in a very hot room or in direct sunlight once the PA exceeds the maximum allowed temperature the radio will go into protect mode until it returns to safe temperature.

The new radios have an even better cooling system because of it’s lager heat sinks and lager fans.!
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Tim - W4TME, Customer Experience Manager

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Official Response
60C is 10 degrees under the threshold where the fan starts rotating at high speed.  You're fine.
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KC2QMA_John

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What is the temp that will cause a 6600M to shut down?

What is the final used in a 6600M, I could not find that info anywhere?
(Edited)
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K3SF

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Hi John

This is just a few thoughts... 
Flex and any other manufacture do not release info for various reasons.

One...could be sued if equipment does not perform to something they publish.

Two... could be Trade Secret....
            it is not a 'Trade Secret' if you tell someone
            NOTE: Rather than patents,
                        Trade secrets are used to protect Intellectual property
                       ...another legal issue

Asked Coke Cola about Trade Secrets..
          you know the formula to make it ;-O

and

like my Dad would always tell me..."You cant always get what you want"
or
was that the Rolling Stones

i quote the Rolling Stones some more:

  And I went down to the demonstration
  To get my fair share of abuse
  Singing, "We're gonna vent our frustration
  If we don't we're gonna blow a fifty-amp fuse"




this is just food for thought....

Paul K3SF









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KC2QMA_John

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 I could understand some of the proprietary aspects of the radio being “Classified” but What final is used and shutdown temp???.

That’s absolutely ridiculous!!!!
(Edited)
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Neal Pollack, N6YFM

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As Tim said, it's fine for the radio.   However, keep an eye on your antenna "system".
My testing over the last year, both at the QTH, and IOTA, and field day, is that band pass
filters and antenna match boxes (with ferrite toroids) do NOT like power.   They are rated in
a B.S. Fake News term called ICAS.   Study it, and puke.   For example, testing revealed that
popular antenna's with 2 kilowatt match boxes could really handle about 250 to 300 watts FT8
before dangerous heating occured that can destroy the toroids in the match box.
Testing on 200 watt bandpass filters at IOTA with 80 watts FT-8 all day, melted the glue off
the coils inside the bandpass filters.   The vendor, Array Solutions, sent a larger one they designed,
but then went radio silent when I mailed them a lab test report on the heating.

When the ferrite material gets too hot, the binder in the powder starts to break down.
The permeability is permanently changed.  SWR will begin to climb.   Time to buy a new one.

Magnetics don't like power.    SSB is only about 30% duty cycle.   FT-8 is keydown 100% for 15 seconds.   In playing with temperature probes and dummy loads on the lab bench, your jaw will
drop at the results.   So far as I can tell and test, none of the antenna match boxes and bandpass
filters on the market today have a derating specification for digital modes.   And they CAN NOT
handle the rated power, if running FT-8.

User Beware.   It's not your radio that will complain, it's the antenna and feedline filters and match
boxes.  (This is one exmaple of many, where having a Steppir Antenna might make sense.  If you can match the size of the antenna at the frequency, so that you don't need a match box with toroids, then you can really handle full legal power key down in all digital modes.)

My rotating 4-band dipole and my multi-band wire are both rated at 1500 watts.  But both have
Ferrite Toroid match boxes.  Experiments now have me limited to 250 watts MAX for FT-8 (After letting the purple smoke out of a few :-) )

Cheers,

Neal
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KI4P

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Well, there you go, a reason not to mess with the computer part of the band! Ha!
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N5LB - Lionel B

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Excellent point about magnetics.  The Flex in many cases, maybe most, will be the strongest element in the entire antenna system/transmitter.

I've seen the SWR creep up using FT140-31 or 61 (don't recall) at full T4X power.  I stopped pre-smoke.  SWR creep as you note, hopefully not leap, is a warning.  I homebrew all of my baluns/ununs, some actually work as intended, but lessons learned.

Good info Neal.

I'm pretty sure my 6400 will protect itself from ME.
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KC2QMA_John

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What is the Specific temp that will cause a 6600M to shut down?

What is the final used in a 6600M, I could not find that info anywhere?
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Chris DL5NAM

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Make no sense if you ask here same question 10 times - it's a user board. Technical support make only FRS direct, so try to phone them or write a email

Chris
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Michael N3LI

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Go all caps next. Bold type isn't yelling loudly enough. Hey John in all seriousness - we are the user community, not the designers and holders of the specifications you are demanding. You might try communicating with Flex directly, instead of becoming angry with us because we don't know. 
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Joe N3HEE

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John is not angry with us !  He just wants some simple answers.  AND SO DO I :)
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KC2QMA_John

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Who's mad?

Sorry about the caps.

What is the Specific temp that will cause a 6600M to shut down?

What is the final used in a 6600M, I could not find that info anywhere?

Would it be possible to raise the RPM limit in a future version of SSDR to accommodate the above fan?
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Neal Pollack, N6YFM

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So, again, call Flex and put on a support request.
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Michael N3LI

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John  - I don't think anyone here in the user community  knows the wisdom you seek.  We are not paid employees or designers of these radios. We're users, just like you. Flex is pretty accommodating, and I'll bet if you ask them, they might just tell you. 

Or have you already tried contacting them directly and they have refused to accomodate you?
(Edited)
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KC2QMA_John

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left message Friday afternoon ...
(Edited)