[RTTY] Amp/Temp

[groupsrichart at gmail.com]

The Alpha 86 is a real beast. According to the manual the manufacturer 
rated it for "continuous operation at a power output of 1500 watts PEP, 
keyed CW, SSTV, RTTY or AM, with no time limit (rated for continuous 
commercial service, "CCS")." If you have been using it for 20 years and 
not experienced any problems, then I don't think you need to change a thing.

Tim KM4GA

On 10/7/2017 10:58 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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