[Elecraft] Rec antenna protection

[Hank P]

The external reed relay /miniature relays are OK  IF they are keyed by the 
key line  AND the RF is delayed a few ms from key line down.(K3 does this) 
The diode limiter circuits like the AS and others like that don’t have this 
limitation.

BUT I would be interested in the OFFICIAL Elecraft position on their COR

What bothers me about it is that if the internal relay is clicking , it has 
to already have seen enough RF to be considered potentially damaging in 
order for the K3 to decide the relay needs  to be actuated . So the barn 
door is closed after the RF has been applied for an unknown  period but 
surely a couple milliseconds.

I am a belt and suspenders  type guy especially with expensive equipment - 
and my feeling is that the K3 COR is telling me to DO SOMETHING ABOUT IT 
NOW. I would never continue to operate with it actuating. I treat it as a 
nice warning thing Mr. Elecraft has given me, not something to be used 
continuously.

I made my own RX ant protector with a  little DPDT miniature relay  that has 
gold plated contacts . It is wired so the rx ant line is opened and also the 
K3 rx input is shorted. One could argue which should come first I guess but 
I get over 100 dB isolation on 160 measured with VNA.

Hank K7HP

>
> I'm looking for a device to protect my K3S front end when using a RX 
> antenna. As I key my rig I can hear the COR clicking and it's making me 
> nervous.
>
> I have seen the AS-RXFEP review by W1ZR in QST.  I have also seen devices 
> with reed relays on the web. What are you using or am I just foolish to 
> worry about this?
>