On 2011-12-22, at 12:54 PM, Curt wrote:
> All looks ok EXCEPT..the one tube that was bright has a small suck-hole thru
> the side of it. It got so hot, the glass melted and a hole was sucked thru
> the side without breaking the rest of the tube. YIKES>
Hi Curt,
That happened to me one time here, too, only the circumstances were a bit
different...
I had a brand new pair of 811A tubes in my 500-watt amplifier, & had just
purchased a Yaesu FT-980. I got so enamoured with my being able to "...raise
the average talk power" of my SSB signal by virtue of the new rig's speech
processor that after about 5, or so, DX QSOs on 20-meters, the fuse in the
amp's power supply popped. I replaced it with a new one, and again, it blew...
So I took off the amplifier's covert & examined the new tubes...and lo &
behold, there was a tiny pin hole in the envelope of one. I guess my speech
processor raised the plate dissipation of those jugs as well as my "...average
talk power", to the point that the one tube got so hot the glass had softened,
& the vacuum was sucked out!
I've never used a speech processor since that time.
~73~ de Eddy VE3CUI - VE3XZ
_______________________________________________
Drakelist mailing list
Drakelist@zerobeat.net
http://mailman.zerobeat.net/mailman/listinfo/drakelist
