Well, that's no surprise.
Don't run any more than 30% of maximum power in FT8 mode. That
goes for radios and amplifiers.
Stick to that and you'll never have a problem.
73, Alek VK6APK.
On 3/03/2024 12:55 pm, Arturo LU6ETB
wrote:
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Hi,
Last week my Alpha 78 stopped working.
I found the windings of the L5 was burned.
I rewinded the toroid with new wires.
Now, it is working.
I checked the temperature after transmitting on 80 meters FT8 with
approximately 1 KW output.
Plate current 0.85 Amper, HV 2000 V and Grid current 25 mA.
After 30 minutes the temperature readings with a digital
multimeter were.
L5 119 C (246 F)
L4, 64 C ( 147 F)
L6, 49 C (120 F)
Are those temperatures right?
What maybe the cause of the high temperature?? ?
Should I have to replace also
el toroid???
?
Thanks in advance for the comments.
73 de Arturo, LU6ETB
