In thinking about oscilloscope sections (see
>
formatting link
for
> background), I want a high bandwidth (out to about 20MHz) SPDT switch:
> something a little faster than a relay, maybe do a clean 1MHz with
> corresponding rise time (under 50ns would be good).
>
I've always been a happy user of the SD210 series MOSFET switches. I've also used the NXP BSD22, which is similar, but cheaper. Alas, they are all discontinued.
NXP still has the BF1108, which has a rather lower RDS-on, but also much lower voltage ratings.
Regards, Jeroen Belleman