Tnx Jon: It is usually Rich that gives me problems - I understand sometimes
not what he means. If it is his own private way to express himself or
american slang, I do not know. Sometimes you have your own private direct
quarrel not seen on the reflector. Which makes it even more complicated when
I have to put the messages in the right surrounding, so to say.
73s de Hans
----------
>Från: Jon Ogden <jono@enteract.com>
>Till: sm5ki <sm5ki@algonet.se>, Amps Reflector <amps@contesting.com>
>Ämne: Re: SV: [AMPS] Power Handling of Resistors
>Datum: ons 8 mar 2000 00.47
>
>
>on 3/7/00 4:09 PM, sm5ki at sm5ki@algonet.se wrote:
>
>> No it is very tiring to try to follow this endless dicussion in US English.
>> What on earth are some of you trying to prove? I have been sitting here for
>> more than 1 hour trying to read to-days endless Kindergarten discussion. For
>> my piece in mind I have soon to leave this amps net.
>
>I don't know how to write more clearly. Sorry.
>
>I believe that parasitic resistors that are found to be bad are damaged by
>heating over long periods of time and not by parasitic oscillations as Rich
>suggests.
>
>Rich's theory says that a parasitic event of a large enough magnitude can
>occur so quickly that it burns up the resistors from the inside yet, you
>don't see any indication on the front panel meters of the amp. He says it
>is that quick.
>
>To not move the meters, the oscillation must have occurred in a time less
>than a few milliseconds. Perhaps much, much less.
>
>In my experiment, I generated 320 Joules of energy across a 6 Watt 50 Ohm
>resistor at 144 MHz.
>
>A Joule is defined as 1 Watt-Second. So to find the number of Joules you
>multiply Watts times Seconds. 160 Watts (my output power) * 2 seconds (key
>down time).
>
>Let's say that our parasitic oscillation event took place in 0.5
>milliseconds of time. Let us also say that I am using the same resistor
>network in my suppressor that I used in my bench testing. We know that it
>is capable of handling 360 Joules of energy without being destroyed. At 0.5
>milliseconds, 320 Joules means that my output power is 640 KILOWATTS!!!!!!
>
>What tube in amateur service is capable of generating 640 Kilowatts of power
>at VHF frequencies???
>
>So, then how could a short, extremely intermittent parasitic oscillation
>have destroyed the resistors in the suppressor?
>
>I would like to know.
>
>I hope this puts the context of all this in easier to understand English or
>American! :-)
>
>73,
>
>Jon
>KE9NA
>
>-------------------------------------
>Jon Ogden
>KE9NA
>
>Member: ARRL, AMSAT, DXCC, NRA
>
>http://www.qsl.net/ke9na
>
>"A life lived in fear is a life half lived."
>
>
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>
>
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