[time-nuts] Switching 1 pps signal

[Anders Wallin]

Hi Taka,
I made an 1:8 multiplexer with TE HF3 relays. They are specified up to 3
GHz, but the 'tree'-design has log2(8) = 3 levels - i.e. the signal always
passes through three relays.
in practice I got around 1 GHz -3dB bandwidth, which I think is OK for 1PPS
http://www.anderswallin.net/2018/05/mux-in-a-box/
I should measure and document the 1PPS rise-time/shape before and after the
multpliexer..

If someone knows of a significantly better relay than the TE HF3 at similar
price then that would be an improvement..

Anders

On Sun, Jul 7, 2019 at 12:01 AM Taka Kamiya via time-nuts <
time-nuts at lists.febo.com> wrote:

> I am trying to come up with a viable design to encase TICC along with
> 10MHz -> 1 pps converter.  My plan is to share the input connector and
> switch in/out the converter.
>
> 1 pps, although technically a 1Hz signal, rise time and duration is
> awfully short on some sources.  I'm sure constituent signal will go way
> into RF range.  I am not capable of calculating this.  But, that means I
> really have to treat it as an RF signal, correct?  Otherwise, slower rise
> will cause error as it will cross the threshold later than initiation of
> the pulse.  Question is, how careful do I need to be?
> My plan is to use two 18GHz microwave relay per channel to bypass/place-in
> the converter.  I know this would be OK but am I over-doing this?  I also
> have a miniature relay in DIP size but I'm afraid it may not be
> sufficient.  There is not a frequency spec, and consistency may be an issue.
> Advise, please?
>
> ---------------------------------------
> (Mr.) Taka Kamiya
> KB4EMF / ex JF2DKG
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