[Amps] lk-450NTC

ko1h ko1h at cox.net
Thu Mar 15 20:28:20 PDT 2012


Hi all,  Just acquired a lk-450ntc.  Had some trouble getting the tube to light but then all was well for a few days.  ( I did a stupid when trying to get the tube to light and will have a nice scare on my left pinky to tell tales about)  But be that as it may.  After getting the tube to light (Friday last)  I hooked it up and was getting power out on 75 into a dummy load and antenna.  Didn't mess with it for a few days turned it on tonight and a few seconds after hitting the power switch I got a pop in and I think I saw an arc in the rf compartment.  

Figuring heck this happens ( I used to own a few sb220/1's that loved to bang everyonce in a while) I kept the amp in standby verified that the exciter was turned down enough and the swr to the antenna was good and fired it up.  Well SWR back to the radio when the amp is keyed to goes through the  roof and the idle plate current in the amp drops to zero.  Placing the amp in standby and through to the antenna a just fine.  Tube is lit.  2900v on the meter for idle dc voltage.  Relay can be heard engaging.  

Due to this thing biting me last week ( my own stupid) had it turned on and touched it with the covers off I know luck I'm here)  I've got it unplugged and sitting for the night before I take the covers off.  

Any place I should start to look? 

Perhaps reseating the tube.  The socket on this thing does not please me and will likely get replaced eventually.  
Relay?
Glitch resistor on the tub?

Anything else?  (aka the reason I'm posting this most people know more/better than I do. )


Thanks de John ko1h 


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