[Amps] ALPHAs and momentary power outages

[Dick Green WC1M]

I have an 87A and 2000A here, too, and have always liked the 2000A's short
warmup after power down and immediate restart.

I'm virtually certain the three-minute timer is implemented in the 87A
firmware, not an external circuit. But my understanding is that the code
space is really tight, so it might be difficult to add code like the 2000A.
If you could locate the timer value you could patch it to a lower value on
the fly when you get a short duration power interruption, then patch it back
for normal startup. A patch like that is not for the faint of heart and
would certainly violate the warranty, but if I knew the timer value address
I'd do it under circumstances like Yuri faced. I'd keep a laminated cheat
sheet handy!

Of course, the question is -- what's the startup timer value address? I
suspect Alpha won't be willing to give you that information, but you can
always ask. If you find out, let me know!

73, Dick WC1M 


> -----Original Message-----
> From: Paul Cassel [mailto:paul at ve3sy.com]
> Sent: Monday, July 16, 2007 8:35 AM
> To: amps at contesting.com
> Cc: 'Paul VE3SY'; 'Yuri VE3DZ'
> Subject: [Amps] ALPHAs and momentary power outages
> 
> I operate an ALPHA 87A and as everyone is aware there is a 3 minute or
> so
> filament warm-up cycle.
> 
> During the IARU test, my QTH was used by Yuri VE3DZ.  The area has been
> having some electrical weekend grid work  and as a result of several
> momentary power interruptions, <2 sec, he lost several good runs at QRO
> as a
> result of being forced to wait for the 3 min recycling of the AMP
> timer.
> 
> Has anyone hacked the Alpha circuit that would sense the duration of
> filament voltage loss and change the timer accordingly?  We were also
> running an ACOM 2000A however if I recall the ACOM timer varies based
> on
> measured tube temperature?
> 
> Thanks for your ideas?
> 
> Paul VE3SY
> Yuri VE32DZ
>