Try 1000 watts for one month.  Then  500 watts for the next month.  Don’t tell 
anyone. 

Unless you are trying to get that last country for your stats you won’t see any 
difference in your enjoyment and contact ratio.  How often do we turn our 
receivers, stereos, ovens, microwaves, irons, or even car engines up to their 
max just “because we can”?  Not trying to start a flame war here but to me it 
does make sense to give our equipment some breathing room? 

Yesterday while monitoring a group of guys around Michigan on 75 meters one of 
them dropped down from his KW to 12 watts and everyone was amazed he was still 
20 dB over S9.  They were over 100 miles apart too.

Many of my friends have over 300 countries or have worked all counties and have 
never used over 500 watts, mostly 100 watts.

Yes, it is good to experiment to find out why this is occurring, but after that 
give your amp some room to breathe.  I watch this list for education and 
haven’t ever seen a rating of how high the Elecraft 1500 watt amp is tested at, 
what is its actual max output and for how long.  I would guess that if it’s 
designed to handle 3000 watts then 1500 watts is conservative and this problem 
shouldn’t be happening.  If it is tested and burned in at 2000 watts then it is 
being pushed and heating might be a problem on some amps.  I have watched a few 
other comments on the Elecraft 100 watt amp and they have troubles getting an 
actual 100 watts out all the time too.  Rain, ice, and other factors change 
things too.  Isn’t this hobby fun?

Just a thought.

Dave K8WPE

David J. Wilcox K8WPE’s iPad

> On Mar 15, 2019, at 9:27 PM, K9MA <k...@sdellington.us> wrote:
> 
> Hi Gary,
> 
> I haven’t seen that problem unless the SWR was at least 1.4:1. However, it’s 
> possible you have hit just the wrong phase angle.  If your 1.2 SWR resulted 
> in a load impedance of 42 Ohms, the current could go up 20 percent. On the 
> other hand, 55 A into 50 Ohms sounds a bit high. Make sure the voltage isn’t 
> dropping more than a couple Volts.
> 
> 73,
> Scott K9MA 
> 
> ----------
> 
> Scott Ellington
> 
> --- via iPad
> 
>> On Mar 15, 2019, at 1:25 PM, Gary J Ferdinand <alapa...@w2cs.net> wrote:
>> 
>> I’m in the process of checking out my amp.  I have two dipoles (40 and 80).  
>> At resonance both show a 1.2:1 SWR with ATU totally bypassed.  With ATU on, 
>> it remains bypassed on 80, but shows only the ATU ON LED on 40.  In both 
>> cases the resultant SWR is 1.2:1.   SWR measurements are from the KPA1500 
>> display.
>> 
>> When I use the amp with my K3 and drive it up to 1500W, I am occasionally 
>> getting an excessive PA current fault at 63A.  From a cold start it’s 60A, 
>> but as it warms up in contest usage I find the power drops off, so I have to 
>> adjust the K3 to bring it back up to 1500W.  At that point the PA current 
>> goes over 60A.
>> 
>> Interestingly, into a dummy load the 1500W point shows a PA current of only 
>> 55A.  So the 1.2:1 SWR, be it via a bypassed ATU or using the ATU, is 
>> sufficient to raise the PA current eventually to excessive levels.
>> 
>> Suggestions?   I don’t want this to be flipping out during a contest.  I 
>> also don’t want to reduce power into what should be a totally acceptable 
>> load.
>> 
>> 73
>> 
>> Gary W2CS
>> 
>> 
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