>Dick Flanagan wrote:
>>
>> At 1:37 AM -0800 2/10/98, Rich Measures wrote:
>>
>> >>Is this the kind of switching normally provided by something like the
>> >>outboard Ameritron QSK-5 or am I confusing it with something else?
>> >>
>> >I know zero about this product, Dick. Does it use a high speed vacuum
>> >relay or a PIN diode to switch the output?.
>>
>> PIN diode. See http://www.ameritron.com/other/qsk5.html
>
>The info at this address claims that a vacuum relay can 'barely keep up
>with' modern QSK transceivers,
This is true if one does not use some variation of Jenning's recommended
speedup circuit. Apparently, Ameritron's engineer did not have enough
time to read Jennings' relay catalogue.
> and a PIN diode system is better for that reason.
Folks who live in areas with a high incidence of lightning report a high
rate of failure with PIN diodes.
> I can tell you that a vacuum relay --when used with a current-limited 150v
source-- can
>keep up with a TS-850s with the internal keyer set a maximum (probably at
least 55
>wpm). I put a scope on my rig and saw absolutely no difference (except
amplitude) in the
>output with full QSK when the amplifier is on or off. Relay life with this
system is an
>unanswered question, but it cost me about $75 to implement as opposed to
>the $349 .that Ameritron wants.
- Relay life should be about 2 million operations, Vic.. . . PIN diode
life is very roughly a couple of moderate lightning storms.
cheers
Rich...
R. L. Measures, 805-386-3734, AG6K
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