[RTTY] Amp/Temp

[Mark Mumaw]

My Acom 2000A will regularly get up to 70C (158F). With your rear intake 
fan,the added exhaust fans and assuming you have good ventilation, 
especially on the intake, I wouldn't  be too concerned.

I have been doing some thermal testing on a legal limit solid state 
LDMOS linear and I see temperatures around 60-65C on long transmissions. 
Of course this is a very different animal.

I like the temperature controller below for turning fans on/off 
depending on temperature. I used it on my homebrew 3.2KW dummy load to 
automatically run the fans above 45C.
See
http://www.ebay.com/itm/W1209-precision-temperature-controller-50-to-110-degrees-/121387155292?hash=item1c433cff5c:g:Z14AAOSwDk5TxeZ3

Mark NU6X  Sedona, AZ

On 10/7/2017 7:58 AM, Courtney Judd wrote:
> I am looking for any ideas or your thoughts on what would be the safe 
> or maximum operating temperature of a HF amplifier in rtty operation. 
> My setup here is a FT5000 driving an Alpha 86 to about 1200 watts on 
> rtty.... it will do considerably more on cw/ssb and rtty but I felt 
> that I should limit it on rtty. What started all this is that after 
> about 20 years of just sitting up on the shelf doing it's thing, I 
> decided to take the 86 apart and give it's internals a good cleaning. 
> Sure enough, the dust bunnies had been doing their thing. Gave it a 
> good cleaning but when i went to put it back together i noticed that 
> on the back panel where the air enters the amp there was a pre-made 
> place to install a fan. I put a 115 v fan to push air into the amp 
> which goes past the transformer then into the fan below the tubes and 
> then out the top thru the tube shields. On top over the vent holes I 
> built a Styrofoam box with two fans to help pull the air out. Sorta a 
> push-me-pull setup. I bought a couple of digital thermometers with 
> sensors. I placed the probe in the airstream coming out of the amp 
> over the fans in the Styrofoam box and the other the air coming out of 
> the 5000. This is where it got interesting. On rtty when running the 
> 5000 would get up to about 103 deg F. from a resting temp of 79 deg. 
> The amp would go from 90 deg up to a high of 155 deg which sorta made 
> me nervous. I asked my wife if eggs would fry at 155 and she said 
> probably! SO, do you guys monitor your amp's temperature and what do 
> you all think is save? Sorry to be so long winded but I am curious! 
> thanks and 73's Cort K4WI
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