[AMPS] 8877 3 min time delay
Phil Clements
philk5pc@tyler.net
Wed, 20 Oct 1999 09:50:45 -0500
Dick,
> I use a common HV supply for my 6M and 2M amps that use 8877s.
> However, I have the heater voltages on each tube set up with 3 minute time
> delay so I can never make the mistake of applying the HV without having had the
> heater warm and ready to go. I use a vacuum relay to switch the HV and a fail
> safe system that prevents the HV from going to either amp if the selected amp's
> heaters have not been warming up for 3 minutes. Good luck.
> Roger K8RS
>
You went to a lot of trouble and expense. The HV can be there all the time.
You just need to prevent the PTT relay from closing for 3 min. after the filament
lights. All Alpha amps that use 8877's apply HV the instant you turn the amp on.
(((73)))
Phil, K5PC
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