[Elecraft] FSK power

[Ray Sills]

The difference in power between 50 watts and 100 watts is essentially  
insignificant.  If you can't work 'em at 50 watts with the antenna  
you have... 100 watts ain't gonna make the difference.  Period.   500  
watts... 1KW.. OK.. maybe that'll help.

Just because the rig can "take it"... the extra power and dissipated  
heat is just wasted.

My opinion.

73 de Ray
K2ULR
FN20kg
Warrington, PA


On Sep 23, 2010, at 3:02 PM, Richard Ferch wrote:

> The specifications for the transmitter in the Owner's Manual say  
> 100% 10
> min 100W key-down at 25 C ambient, so RTTY at 100 watts is within spec
> even for extended transmissions, and an RTTY contest with its short
> transmissions should be no problem at all at 100 watts.
>
> You can monitor the temperature of the finals by tapping the DISP key
> and rotating the VFO B knob until you see PA xxC (where xx is the
> current temperature). I believe there is a protective thermal shut- 
> down
> somewhere up around 80C, but I doubt whether you will come anywhere  
> near
> that. Mine gets into the mid-50s near the end of long transmissions
> during digital mode ragchews, but it doesn't get that hot during
> contests. The ambient temperature has a significant influence, too.
>
> If you do monitor the PA temperature, don't be surprised if you  
> observe
> temperature readings that are slightly higher during receive than  
> during
> transmit periods. The voltage drop in the power cable at the high
> transmit current draw results in lower voltage at the rig, which in  
> turn
> causes the temperature indication (not the actual temperature) to drop
> slightly. In digital modes I often observe the fans speeding up in
> receive and slowing down in transmit when the PA temperature reading
> happens to be close to the threshold for a fan speed change. I found
> this disconcerting at first, until I realized what was happening!
>
> 73,
> Rich VE3KI
>
>
> NR4C wrote:
>
>> Now, one more. How much power can I safely use with FSK? I have made
>> several contacts so far at about 50 watts. Can I use more? there is a
>> RTTY contest this weekend, and I don't want to damage the radio, but
>> don't want to start off with a weak signal if I can do better.
>
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