[TenTec] AUX Keying OminiVI Plus

[Ken Brown]

Or if you don't want even the tiny click of a reed relay (someone has 
claimed it is not true QSK if you can hear a relay click) you could use 
an optocoupler. LED in optocoupler only needs a few mA, not enough to 
bother that transistor, and no inductive kickback. Maybe even faster 
than a tiny reed relay.

Dr. Gerald N. Johnson wrote:
> 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.
>