Tnx for the info, Paul. Yes, in principle 7mS is fast enough, but the
data sheet doesn't specify contact bounce which, for this type of
relay typically adds another 4-7mS. Even vacuum relays (excepting the
RJ1a) often have that much bounce. Unfortunately, the Flex specified
relays are DPDT type, which rules out a simple vacuum relay swap.
The only clue I could find about the required 20mS delay is in the
user manual, which attributes it to a required amp tuneup time. That
might make sense for SO2R operation, but for ordinary non-SO2R use
seems to me the only need for the amp to retune itself would be for a
band change (as in the Alpha 9500 in the AUTO mode). Seems like a
simple firmware change could give the user the option of toggling
on/off SO2R operation.
Considering how much care went into the design of the Flex amplifier,
which in many ways is quite remarkable, it’s surprising how basic CW
operation seems to have been shortchanged.
73,
Jim w8zr
Sent from my iPhone
> On Oct 7, 2018, at 1:10 PM, Paul Christensen <w9ac@arrl.net> wrote:
>
> Jim,
>
> I did locate the Finder datasheet on the Newark/Farnell website. Watch for
> text wrap:
>
> http://www.farnell.com/datasheets/2611932.pdf?_ga=2.102231233.1928605109.1538931238-590108331.1506213021
>
> Note that specified operate/release time is "7/3 ms (12/4 ms sensitive)." It
> may be a well-made relay and could serve for the amp's antenna output
> switching function, but for T/R, it would be way down on my list among relay
> candidates.
>
> If the Flex amp is specified to work with a 20 ms RF turn-on delay, Flex's
> spec may be conservative -- or it's comprised of the relay time plus an
> additional software or hardware transition time. I suspect these relays
> would settle in time for fast semi-break-in. But for my CW QSK operating, 20
> ms is almost an eternity!
>
> Paul, W9AC
>
>
>
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