Temperature and fan speed Flex 6500

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  • Updated 3 years ago
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I have a Flex 6500 I have been using on CW for about 3 months. Running vs 1.10.16. I run 100 watts into a low SWR antenna.

Typical CW transmission 5 minutes on, 5 off, I run 30 to 35 wpm. Using DDUtil before transmission the internal temperature about 10 degrees F higher than the room. Shack typically at 70F. Flex at 80F. As I send CW the temp rises to about 125F during a 5 minute transmission then cools down over 5 minutes to about 90F than repeats up to 125F on next 5 minute transmission. Fans do not change speed as far as I can tell. 

1. Is this typical?

2. Are there any specs on when the fans will increase speed at a specific temperature?

3. Are the fans supposed to increase speed?

4. At what temperature will the Flex 6500 fail or stop transmitting?

Thanks for any information.

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Tom K3TF

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Posted 3 years ago

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Tim - W4TME, Customer Experience Manager

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Official Response
Answers to questions:
Q1: Reasonable.  Since airflow around the radio impacts its cooling efficiency, there isn't a "typical" value.

Q2: The chassis fans will spin up to high when the internal temp reaches 60 deg C (140 deg F)

Q3: Yes

Q4: The radio will generate an excessive thermal condition warning at 100 deg C (212 def F) and shut down at 120 deg C (248 def F).  Personally, I have no recollection of anyone every experiencing a thermal shutdown.