[Elecraft] K3 external qro keying line

[John Lemay]

I can see reason for confusion here - the K3 Manual on page 17 describes the
"amplifier T-R relay keying output ...."

Maybe the wording could be clarified. I would certainly form a (incorrect)
picture in my mind of a small power relay, for which + or -ve switching
would be permissible.

John G4ZTR


-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Tom Hammond
Sent: 12 February 2009 17:19
To: Lee Buller; Elecraft Reflector
Subject: Re: [Elecraft] K3 external qro keying line

The K3's T-R line output ("KEY OUT") can switch up to 200VDC @ 5A... so it
will
easily switch the +120VDC @ 15-30mA from the SB-220.

However, it will NOT SWITCH a NEGATIVE T-R line voltage UNDER ANY 
CIRCUMSTANCES!
Users with amps which offer a negative T-R line control voltage will have to
provide alternate switching (relay, or solid state).

73,

Tom   N0SS

>phones, mic,
>line in, and line out


At 10:13 02/12/2009, Lee Buller wrote:


>HMMMM....  I thought the transistor on the K3 doing the switching is 
>pretty tough.  I guess we are talking about older amps and not the 
>ones that use 12 volts to switch.
>
>I have done the following to....  Radio Shack sells a 5v reed relay 
>that is pretty darn fast and has good specs.  I just used a dropping 
>resistor from a 12 volt line in series with the reed relay and 
>worked great for years.  I think I used a 180 ohm resistor.  Worked 
>great.  Not QSK, but I don't like QSK anyway.  Messes with my head.  HI
>
>Lee Buller - K0WA
>
>
>
>In our day and age it seems that Common Sense is in short supply. If 
>you don't have any Common Sense - get some Common Sense and use it. 
>If you can't find any Common Sense, ask for help from somebody who 
>has some Common Sense. Is Common Sense divine?
>______________________________________________________________
>Elecraft mailing list
>Home: http://mailman.qth.net/mailman/listinfo/elecraft
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Elecraft at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:Elecraft at mailman.qth.net

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3849 (20090212) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com


 

__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3850 (20090213) __________

The message was checked by ESET NOD32 Antivirus.

http://www.eset.com