Elecraft

OT: definition of semi-breakin

Classic

List

Threaded

6 messages Options

Edward R Cole

OT: definition of semi-breakin

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.

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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

Johnny Siu

OT: definition of semi-breakin

Hello Gentleman,

I was told that full QSK means you can hear between di and dah. If this is correct, hearing between letters is NOT full QSK.

TNX & 73,

Johnny VR2XMC

________________________________
寄件人︰ Ron D'Eau Claire <[hidden email]>
收件人︰ 'Edward R Cole' <[hidden email]>; [hidden email]
傳送日期︰ 2012年12月5日 (週三) 8:45 AM
主題︰ Re: [Elecraft] OT: definition of semi-breakin

IMX "semi breakin" means that you do not need to physically throw any
switches to go from transmit to receive.

Compared to "QSK", in semi-breakin you typically do not hear any signals
between code characters, letter or even words. Often the timing is variable,
but I've never seen anything approaching a specification for the fastest
switching that qualifies as "semi-breakin" any more than I've seen a
specification for the slowest switching that qualifies as QSK. Some consider
a rig full QSK if one can hear between letters, others expect to hear
between code elements.

73 Ron AC7AC

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Edward R Cole
Sent: Tuesday, December 04, 2012 4:29 PM
To: [hidden email]
Subject: [Elecraft] OT: definition of semi-breakin

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.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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

Don Wilhelm-4

Re: OT: definition of semi-breakin

In reply to this post by Edward R Cole

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:

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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

Joe Subich, W4TV-4

Re: OT: definition of semi-breakin

In reply to this post by Edward R Cole

Ed,

> 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-break in.
> Also, a precise definition of semi-breakin would be nice.

I don't know that there is a precise definition of the speed needed for
semi-break in. However, you can approach it be considering that most
transceivers have between 5 and 10 msec (the K3 is 8 msec) from key
closure to the onset of RF. *Any* proposed T/R system for an amplifier
needs to transfer from receive to transmit *and settle* in that time.

The transmit to receive time - following the cessation of RF - may be
a bit slower but that is usually set by the semi-break in delay (VOX
delay) in the transceiver - not necessarily the relay transfer speed.

If I were writing specifications "out of the air" - I would probably
shoot for a receive to transmit time between 3 and 7 msec and transmit
to receive time of less than 10 msec but those numbers are essentially
SWAG based on the overall system considerations. Yes, with those
transfer speeds, the same relay(s) could probably qualify as "QSK"
if the transceiver PTT keying line had no delay.

73,

... Joe, W4TV

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.
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

k6dgw

Re: OT: definition of semi-breakin

In reply to this post by Edward R Cole

Being the historical person that I am, I believe the concept of
semi-breakin happened with the KWM2/S-line. CW came from an audio
oscillator that modulated the TX in USB [IIRC]. VOX worked, it
apparently thought it was me talking, and picked up, and when I quit
sending, it delayed whatever I had set on the back chassis, and dropped
the carrier. It was the same delay as when I was on SSB. Until it
dropped, all I heard was my own sidetone or nothing.

Absolute true breakin ... hearing between dits and dahs ... probably
only occurred on maritime duplex circuits in those days. I remember in
the very late 50's, still in college, if your receiver would recover
between words, that was close to QSK ... between letters, "You've made
it!"

Nowadays of course, QSK seems to mean you can hear the station between
dits and dahs. While that may be technically true, I don't think it's
operationally realistic. If I'm QSK [and I am all the time on my K3],
if the other guy needs to interrupt me, he sends ... doesn't matter
what. I doubt I hear specifically between dits and dahs at 20WPM [my
imposed max speed in traffic], but he sends a series of dits or dahs,
and I hear those. I don't know if I hear him between dits or dahs, I
just know he's interrupting me.

I enjoyed the duplex maritime operation, I just heard them between
whatever I was sending. Simplex QSK today blanks the RX noise for the
duration of a dit or dah, and I then hear it, an inverted copy of what
I'm sending. It takes some getting-used-to.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2013 Cal QSO Party 5-6 Oct 2013
- www.cqp.org

On 12/4/2012 4:28 PM, Edward R Cole wrote:

Jessie Oberreuter-2

Re: OT: definition of semi-breakin

I still love the little SST for this sort of thing -- the rx is
always running, so if the other station is loud enough, you really can
work full-duplex!

On Tue, 4 Dec 2012, Fred Jensen wrote:

> I enjoyed the duplex maritime operation, I just heard them between whatever I
> was sending. Simplex QSK today blanks the RX noise for the duration of a dit
> or dah, and I then hear it, an inverted copy of what I'm sending. It takes
> some getting-used-to.
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

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