[Amps] Alpha 9500 Idling Current

[Jim Garland]

That idle current sounds a bit high. I checked my 9500 and the idle current
is 140mA, with a plate voltage of 3680V.  The no-load plate voltage is a bit
over 3800V.

Re the EBS/QSK issue, I'm assuming you're not running the keyer output line
through the amplifier, before it goes to the transceiver. Doing so should
eliminate any EBS timing issues. If you're simply keying the amplifier
directly from the transceiver, then there's evidently a sequencing problem
in the amplifier. I'd think one could compensate for that by delaying the
transceiver RF output for 10mS or so, before closing the AMP relay line. (On
the other hand, if the EBS circuit in the 9500 is triggered off the RF input
into the amp, then that's just bad design! I can't imagine why they would do
it that way, and I don't see any obvious fix other than modifying the EBS
control circuitry.) 
73,
Jim W8ZR

> -----Original Message-----
> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Paul
Christensen
> Sent: Thursday, December 29, 2016 11:35 AM
> To: 'Amps group'
> Subject: Re: [Amps] Alpha 9500 Idling Current
> 
> > "Paul, My Alpha 9500 runs 232 ma idling current with 3535 volts on the
> plate no load and 3420 volts on the plate when idling.  Larry, WA9MAG:
> 
> That amount of Ip idle current seems high to me for the 9500.  Possibly
W6WRT and
> W8ZR can weigh-in with their findings.  Possibly, it was set higher in
software?
> 
> The Alpha 8406 I use on 6m idles at 200+ mA, but I deliberately set it
high
> in software to help offset an internal EBS timing error.   Hard to
believe,
> but the 8406 was truncating CW characters in QSK mode.  It was so bad, I
first suspected a
> fault with the RF input sensor but it's sensing fine.
> When observing a QSK-keyed CW waveform on a scope, the 9500 suffers from
the same
> EBS issue, albeit it's much more subtle and as is typically the case
> with EBS, it only affects the very onset of the waveform.
> 
> Paul, W9AC
> 
> -----Original Message-----
> From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Larry P.
> Greenberg
> Sent: Thursday, December 29, 2016 12:25 PM
> To: amps at contesting.com
> Subject: [Amps] Alpha 9500 Idling Current
> 
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