On Wed, 27 Jan 2010, Edmund H. Ramm wrote:

In e.net Michael Black writes:

On Tue, 26 Jan 2010, Edmund H. Ramm wrote:

In cullen writes:

[...]
why is the tube type TR switch no longer made or used?

How did you arrive at the latter conclusion? I for one use an
E.F. Johnson T/R switch.

Have you been to your local ham store and looked over their selection
of T/R switches lately?

Have you overlooked "latter", which refers to "used"?

The fact that you aren't likely to find a T/R switch at your local
ham store (if you happened to still have such a local store) is
an indicator that they aren't used, because if there was demand
surely there'd be a commercial product. One would also see the lack of
separate receivers and transmitters, as I already mentioned, so one
could gather there is less reason for such a device nowadays, and even
fewer are using non-matched separates, so that S-line or the SB-line
or whatever handles the switchover.

The fact that some still use them doesn't negate his statement. Surely
it's only a relative handful, and they aren't visible enough. Enough
time has passed since they were common that many hams likely don't even
know what they are.

In the old days there were multiple reasons for using them, and they
were often simpler than the alternatives. Nowadays, other things take
care of the task, whether it's a current equivalent of the TR switch
hidden away inside that transceiver or something else, so the only
people using them are those who want to run an old type station, or
have some specific use for it.

If he'd asked somewhere else, chances are good nobody would question
his point about "nobody using them" since there is less likely to be
users except by boatanchor types, and chances are good that if posted
elsewhere someone would say "what's that?".

Michael VE2BVW