[Amps] Pin Diodes

[Paul Christensen]

>  I don't believe an amp with vacuum relay T/R
> switching can be considered a full QSK amp.   Yet Alpha advertises the
> 99 and the 9500 as full QSK.   I run my 99 in semi-breakin only. How
> long can a vacuum relay last in full QSK mode?

The vacuum relay in my Alpha 70V has lasted 36 years.  A vacuum relay with 
an appropriate accelerator circuit can switch nearly as fast as a PIN diode.

Paul, W9AC