[Elecraft] OT: definition of semi-breakin

[Don Wilhelm]

Ed,

Semi-break-in to me means has meant that one does not have to listen to 
clacking relays during the QSO, only at the beginning and end of the 
transmission.  Elecraft uses all electronic switching, so for all 
Elecraft gear, that statement is moot - there are no relays to clatter 
either with QSK or semi-break-in.  Semi-break-in means that the 
transceiver does not drop out of transmit state until after some defined 
time (the delay time).

BUT, that does bring up another point - when a non-Elecraft device 
containing relays (such as an amplifier - the time between the amp 
keying signal becoming active and the onset of RF is unchanged by the 
selection of QSK vs. semi-break-in.  If the amp's relays are slow, hot 
switching may still occur.

The K3 does permit a variable delay between Keyout and the onset of RF, 
but for the K2, it is fixed.

73,
Don W3FPR

On 12/4/2012 7:28 PM, Edward R Cole wrote:
> I suppose this forum is a good place to ask as so many are CW ops.
>
> I am evaluating a pcboard relay for switching RF (Tx/Rx) and need to 
> know what speed that the relay needs to qualify for semi-breakin.  
> Also, a precise definition of semi-breakin would be nice.
>
> I get that QSK results in transfer from Tx to Rx after every CW 
> character.  I'm guessing semi-breakin switches when there is a pause 
> in transmitting.  I can evaluate the switching speed of my candidate 
> relays using a storage scope but need a precise number on how fast 
> they need to be.
>
> 73, Ed - KL7UW
> PS: these relays will be switching 300w RF.