[TenTec] AUX Keying OminiVI Plus

[Dr. Gerald N. Johnson]

On Sat, 2007-05-26 at 07:13 -0700, Jim WA9YSD wrote:
> This will be the third time I have to send in my OMNI VI Plus to get the AUX Key circuit repaired.  Could RFI be blowing this for me?  How do I prevent this from going out?  Is there a better fixe out there?
>    
>   K9TF/WA9YSD
> 
> 
> Keep The Faith, Jim WA9YSD
>        
What is that circuit keying? Lots of amplifiers key significant voltage
and current which can fry the internal keying transistor and if the
keyed circuit is a relay coil, inductive kick from the coil adds insult
to the driver transistor.

It is quite practical to create a circuit using a small protected reed
relay or a couple MOSFET transistors that will key a few hundred volts
at 20 amps though a couple hundred volts at a quarter amp is usually
enough.
-- 
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer