My 6300 is overheating

Mark K1LSB

My 6300 (running SSDR v2.2.8) has come up with an Overheat alarm in FRStack twice over the last 24 hours, once on 80 meters and once on 40 meters, both times after a couple of minutes of sustained PTT hold-down on SSB rag chew, both times on 55 watts RF drive power into my AL-80B.  I've never seen that problem before, but I may have simply never held the PTT down for that long before.

Both times, when the alarm occurred (which was at an indicated 70 degrees C per the FRStack gauge) the internal fan went into high-speed mode.  I immediately un-keyed the mic and the temperature rapidly dropped back to a lower level.  After less that a minute the temp was back down into the 40's so I continued on with my QSO in a rather less verbose mode.

The radio was purchased second-hand from another local operator less than 4 months ago.  I opened the cover immediately after purchase to inspect the insides.  Everything inside was spotless, with no appreciable accumulation of dust anywhere, including on the fan blades (at least on the fan that's visible when the cover is removed from the radio).  The optional antenna tuner was installed by the previous owner but I've never used it, as the input of my AL-80B is adjusted to be a good match to the radio on all bands (SWR as reported by the Flex and FRStack meters is 1.3 or less on all bands).

Is it normal for a 6300 to overheat on a two-minute SSB transmission at 55 watts out and 1.3 SWR or less?  If it isn't normal, what could the problem be?

Thanks in advance,

Mark  K1LSB

Mike-VA3MW

Hi Mark

I am going to convert this to a support case.

Mike

Neal - K3NC

Mark
Is the temp warning changable in FRStack? You were not getting the message from the radio but from FRStack if I read you correctly. I do remember reading something recently that 70C is not a dangerous temp so I am wondering if possibly its just a setting in FRStack and could be set to anything  that you wanted.

My memory could be wrong on the temp tolerance so I will see if I can find where I read it.

Neal - K3NC

I found what I had read beforehand. The fans should kick into highspeed mode at 60C. 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). 

Are your fans kicking in?

Mark K1LSB

Yes, the fan kicks in but possibly not until 70 deg C.

And you do bring up a good point that hadn't occurred to me.  I only recently started using FRStack so I guess it's possible that I've reached those temps before and just wasn't aware of it.  But I do know that FRStack sure make you aware of it! 

Mark K1LSB

I can't find anywhere in FRStack to change the warning temperature.

Mark K1LSB

Thank you, Michael.

Bill -VA3WTB

It seems to me it is getting warm a little early, it should take longer. Do you have good air around the radio?
But I think Neal Is right also. The flex is well protected, it would shut down before damage can occur.

Mark K1LSB

Bill,

I have good clearance around the radio for cooling, thanks for asking (it hadn't occurred to me to check if maybe I'd inadvertently covered some cooling holes).