I hate spell checkers... It changed my call...
73 again de Don (ki6sz)
>I'll step off the soap-box now...
>Thanks, and 73 de Don (kiss)
-----Original Message-----
From: Tom Rauch [mailto:w8ji@contesting.com]
Sent: Monday, June 07, 1999 8:27 AM
To: Jon Ogden; amps@contesting.com
Subject: Re: [AMPS] TL-922 Filament Transformer Protection
Come on Rich, use your head.
The low pass system on the input of the amp virtually guaranties
the rise time of any pulse is about the same as the rise time of the
desired signal. That's very well known!
As for the relay cathode return closure causing a transient, that
assumption is silly beyond belief! When the relay closes in the
cathode, the bypass capacitors--filament transformer---filament
choke---etc etc all slow the transition down. The slope of the
transient must be less than high audio frequencies after passing
through all that stuff.
I'm amazed you try to propagate such BS in order to explain
something so easily understood.
> >>This (VHF) ringing occurs whenever there
> >>is a transient in anode-current. I contend that RF input contact arcing
> >> (hotswitching) during relay closure will produce transients in
> >>anode-current -- and that the resultant ringing in the anode circuit
> >>will be fed back by the feedback C of the amplifier tube. .
> >
> >HOW?
Good question, now look at Rich's reply......
> ? A spark is reliable producer of wide-band feculence.
As Rich is also!
> >How does closing a relay wether it is a hot closure or not produce a
> >transient in anode current?
> >
> ? hotswitching causes a spark.
So does flint. I guess than means Zippo lighters have parasitics.
> >I always thought anode current (other than bias current) was produce by a
> > driving signal.
>
> ? The spark is connected to a wire that connects to the input of the
> tube.
Through a low pass filter that prevents any transcients faster than
the signal frequency from passing....
> > Hot switching is not good, but I don't think it is a
> >cause of anode current transients.
>
> ? When I was on 1296MHz, I could hear spark-plug interference from
> automobiles 400m distant.
I can hear thunderstorms from Boston on frequencies that will pass
through the input circuit. Thunderstorms must also trigger
parasitics.
73, Tom W8JI
w8ji@contesting.com
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