N6XI NAQP RTTY July, 2007 with K3

classic Classic list List threaded Threaded
22 messages Options
12
Reply | Threaded
Open this post in threaded view
|

N6XI NAQP RTTY July, 2007 with K3

Rick Tavan N6XI
                    North American QSO Party, RTTY

Comments:

Made my 1st RTTY QSO in 37 years the day before the contest.
Thanks to W0YK for goading me into RTTY. Had some social obs
that limited my available time but it was a fun first run.
The K3 worked very well, although I have no RTTY experience
with which to compare it. It was very easy to integrate - just
a DE9-DE15 cable with two resistor-transistor keying circuits
in the DE9 shell gave me true FSK. And a simple stereo audio
cable handled audio output from K3 Line Out to the sound card.
No external transformers or other gew-gaws were required.

Class: Single Op LP
QTH: Truckee, CA
Operating Time (hrs): 6:27

Summary:
 Band  QSOs  Mults
-------------------
   80:   32    11
   40:   59    32
   20:  156    42
   15:    5     4
   10:
-------------------
Total:  252    89  Total Score = 22,428

Club: Northern California Contest Club

Team: Team K3



Posted using 3830 Score Submittal Forms at: http://www.hornucopia.com/3830score/
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Bill Steffey NY9H
WHICH PROMPTS THE QUESTION,,,

was the K3 able to decode RTTY in the window ????
bill

At 12:18 PM 7/22/2007, Rick Tavan N6XI wrote:

>                    North American QSO Party, RTTY
>
>Comments:
>
>Made my 1st RTTY QSO in 37 years the day before the contest.
>Thanks to W0YK for goading me into RTTY. Had some social obs
>that limited my available time but it was a fun first run.
>The K3 worked very well, although I have no RTTY experience
>with which to compare it. It was very easy to integrate - just
>a DE9-DE15 cable with two resistor-transistor keying circuits
>in the DE9 shell gave me true FSK. And a simple stereo audio
>cable handled audio output from K3 Line Out to the sound card.
>No external transformers or other gew-gaws were required.
>
>Class: Single Op LP
>QTH: Truckee, CA
>Operating Time (hrs): 6:27
>
>Summary:
>Band  QSOs  Mults
>-------------------
>   80:   32    11
>   40:   59    32
>   20:  156    42
>   15:    5     4
>   10:
>-------------------
>Total:  252    89  Total Score = 22,428
>
>Club: Northern California Contest Club
>
>Team: Team K3
>
>
>
>Posted using 3830 Score Submittal Forms at:
>http://www.hornucopia.com/3830score/
>_______________________________________________
>Elecraft mailing list
>Post to: [hidden email]
>You must be a subscriber to post to the list.
>Subscriber Info (Addr. Change, sub, unsub etc.):
>http://mailman.qth.net/mailman/listinfo/elecraft
>
>Help: http://mailman.qth.net/subscribers.htm
>Elecraft web page: http://www.elecraft.com

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Rick Tavan N6XI
In reply to this post by Rick Tavan N6XI
Yes, the K3 can decode RTTY and display it on its own LCD, but I
didn't use that feature during the contest.

/Rick N6XI

On 7/22/07, Bill NY9H <[hidden email]> wrote:

> was the K3 able to decode RTTY in the window ????
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

RE: N6XI NAQP RTTY July, 2007 with K3

Ed Muns, W0YK
In reply to this post by Bill Steffey NY9H
> WHICH PROMPTS THE QUESTION,,,
>
> was the K3 able to decode RTTY in the window ????

Yes, the current firmware decodes CW, RTTY and PSK in the VFO-B display
area.  However, it is just the first pass implementation and more tweaking
and functionality is on the way.  This is a great feature (coupled with the
upcoming DATA mode encoding from CW keying) for DATA mode QSOs using just
the radio without a computer.  However, for serious contesting or
DXpeditions, an interfaced PC is desirable.  And, there is the possibility
for the K3 DATA mode decoder to make its output available to the PC as an
alternative to, or in addition to, other software decoders or hardware TNCs.

73,
Ed - W0YK

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

RE: N6XI NAQP RTTY July, 2007 with K3

Bill Steffey NY9H
At 12:50 PM 7/22/2007, J. Edward \(Ed\) Muns wrote:
> > WHICH PROMPTS THE QUESTION,,,
> >


NOW THAT THE ELECRAFT WAY ,,,,

IT DOES THE STUFF IS WAS SUPPOSED TO DO THE FIRST TRIP OUT THE DOOR !!!!!!!

tick...tick...tick....


bill

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Jeff Stai
In reply to this post by Rick Tavan N6XI

 From my perspective, those keying circuits want to be inside the radio, safe from harm. Is there
any reason why they weren't made part of the radio - or why I shouldn't put them in when I get my
K3? (Assuming of course I can get into that part to do so...)

Thanks! - jeff wk6i


Rick Tavan N6XI wrote:
> It was very easy to integrate - just
> a DE9-DE15 cable with two resistor-transistor keying circuits
> in the DE9 shell gave me true FSK.

--
Jeff Stai               [hidden email]
Twisted Oak Winery      http://www.twistedoak.com/
Winery Blog             http://www.elbloggotorcido.com/
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

KK7P
> From my perspective, those keying circuits want to be inside the radio,
> safe from harm. Is there any reason why they weren't made part of the
> radio - or why I shouldn't put them in when I get my K3? (Assuming of
> course I can get into that part to do so...)

The K3 accepts open collector(or open drain) to ground as inputs, or can
be driven with 0 <= x <= +5 volts.

Some stations use RS232 levels (which can be as high as +/- 25V) for
direct FSK.  Such levels need to be converted to 5 volts for the K3
digital inputs.  Further, RS232 specifies a "1" as -3 < x < -25V and a
"0" as +3 < x < +25V, so a polarity inversion (in hardware or software)
is also required.

73,

Lyle kK7P

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Don Wilhelm-3
In reply to this post by Jeff Stai
As a counter to Jeff's perspective, I find that similar things which are
integrated inside the radio will slave that radio to one particular way
of providing that function.  Times change, desires change, but that
radio is locked into the past because of the 'way things were done back
then'.

Moving such functions into a small external box or cable is much
preferable IMHO.

Although it is great that RTTY and PSK31 are built into the K3, I wonder
how long those modes will be used *in the same manner* that they are
today.  Of course, since the K3 does many things in downloadable
firmware, future changes may be possible - but still it would be even
more flexible to use a small interface box.  That is just my opinion and
preferences - they do not have to agree with yours, and I don't want to
argue about it with anyone, just pointing out that what is 'best' for
one is not necessarily 'best' for all of us.

73,
Don W3FPR

Jeff Stai wrote:

>
>  From my perspective, those keying circuits want to be inside the radio,
> safe from harm. Is there any reason why they weren't made part of the
> radio - or why I shouldn't put them in when I get my K3? (Assuming of
> course I can get into that part to do so...)
>
> Thanks! - jeff wk6i
>
>
> Rick Tavan N6XI wrote:
>> It was very easy to integrate - just
>> a DE9-DE15 cable with two resistor-transistor keying circuits
>> in the DE9 shell gave me true FSK.
>
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Jeff Stai
In reply to this post by KK7P


Lyle Johnson wrote:

>> From my perspective, those keying circuits want to be inside the
>> radio, safe from harm. Is there any reason why they weren't made part
>> of the radio - or why I shouldn't put them in when I get my K3?
>> (Assuming of course I can get into that part to do so...)
>
> The K3 accepts open collector(or open drain) to ground as inputs, or can
> be driven with 0 <= x <= +5 volts.
>
> Some stations use RS232 levels (which can be as high as +/- 25V) for
> direct FSK.  Such levels need to be converted to 5 volts for the K3
> digital inputs.  Further, RS232 specifies a "1" as -3 < x < -25V and a
> "0" as +3 < x < +25V, so a polarity inversion (in hardware or software)
> is also required.
>

hi Lyle - I appreciate that - but I believe that in 2007 the chances are pretty darn good that those
inputs will be driven by a station computer, and that serial port is pretty well known - kind of
like the serial port for controlling the radio, right? I'm just saying this was an opportunity to
put the level shift in the radio, and I wonder why it wasn't, and why I couldn't/shouldn't modify my
own K3? thanks! - jeff wk6i

--
Jeff Stai               [hidden email]
Twisted Oak Winery      http://www.twistedoak.com/
Winery Blog             http://www.elbloggotorcido.com/
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

KK7P
Hello Jeff!

>...I'm just saying this was an
> opportunity to put the level shift in the radio, and I wonder why it
> wasn't, and why I couldn't/shouldn't modify my own K3? thanks!

One of the modes that the K3 will use that very same data input pin for
is "direct PSK" in the same sense that it might be used for direct FSK.
  A UART in a PC won't drive such a signal with the correct timing,
it'll have to come from the parallel port, or ???

The K3 input is a general purpose input, not only an "FSK for RTTY"
input, so we tried to make the interface levels general, too.

You could modify your K3 to make it an RS232 level only input, or you
could put a 2N3904 or 2N2222 transistor plus a series base resistor
inside the shell of the DE16 Accessory connector that you wire up for
your station. Or???

Lots of options :-)

73,

Lyle kK7P

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Jeff Stai
In reply to this post by Don Wilhelm-3

hi Don - I'm confused. Open collector FSK inputs have been around for at least 20 years, probably
longer. Radios have already been slaves to that particular way. What I'm saying is "let's make it
easier to get on FSK using a standard DB9 cable, and not require the user to build a special cable."
In this aspect, the K3 is already "locked in the past"!

And I'm afraid my skill set has never been up to the micro-surgery required to build circuits inside
a connector shell.... a much better place for circuits is safely inside the chassis.

73 - jeff wk6i

ps: I predict that RTTY, PSK, CW, and horseback riding will experience no significant changes in the
manner in which they are performed in the next 20 years. :)


Don Wilhelm wrote:
> As a counter to Jeff's perspective, I find that similar things which are
> integrated inside the radio will slave that radio to one particular way
> of providing that function.  Times change, desires change, but that
> radio is locked into the past because of the 'way things were done back
> then'.
>
> Moving such functions into a small external box or cable is much
> preferable IMHO.
>

--
Jeff Stai               [hidden email]
Twisted Oak Winery      http://www.twistedoak.com/
Winery Blog             http://www.elbloggotorcido.com/
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Tom Hammond-2
In reply to this post by Jeff Stai
Hi Jeff:

IF you do, how will you then tell the radio specific serial cable pin
to look at for CW keying/RTTY keying/PTT/etc?

If you place them, as Rick and others do, then you can create
mode-specific interfaces for your software.

IF you put them inside the rig, then THAT particular pin will ALWAYS
be dedicated to that specific task, even though the next software
might want to use a different pin to do the same task.

I'd much prefer to have this sort of thing external to the rig and
just use them to KEY the dedicated input on the rig.

73,

Tom   N0SS

> From my perspective, those keying circuits want to be inside the
> radio, safe from harm. Is there any reason why they weren't made
> part of the radio - or why I shouldn't put them in when I get my
> K3? (Assuming of course I can get into that part to do so...)
>
>Thanks! - jeff wk6i
>
>Rick Tavan N6XI wrote:
>>It was very easy to integrate - just
>>a DE9-DE15 cable with two resistor-transistor keying circuits
>>in the DE9 shell gave me true FSK.

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Jeff Stai

NOW I am totally confused!!! Are you telling me that the connector pins on the K3 for FSK keying and
data will change when`the firmware changes? Or are you saying that those pins are mode specific, and
I will have to disconnect my FSK cables to operate CW or phone?

I'm having a hard time believing that... - jeff wk6i


Tom Hammond wrote:

> Hi Jeff:
>
> IF you do, how will you then tell the radio specific serial cable pin to
> look at for CW keying/RTTY keying/PTT/etc?
>
> If you place them, as Rick and others do, then you can create
> mode-specific interfaces for your software.
>
> IF you put them inside the rig, then THAT particular pin will ALWAYS be
> dedicated to that specific task, even though the next software might
> want to use a different pin to do the same task.
>
> I'd much prefer to have this sort of thing external to the rig and just
> use them to KEY the dedicated input on the rig.
>
> 73,
>
> Tom   N0SS
>
>> From my perspective, those keying circuits want to be inside the
>> radio, safe from harm. Is there any reason why they weren't made part
>> of the radio - or why I shouldn't put them in when I get my K3?
>> (Assuming of course I can get into that part to do so...)
>>
>> Thanks! - jeff wk6i
>>
>> Rick Tavan N6XI wrote:
>>> It was very easy to integrate - just
>>> a DE9-DE15 cable with two resistor-transistor keying circuits
>>> in the DE9 shell gave me true FSK.
>
>
>


--
Jeff Stai               [hidden email]
Twisted Oak Winery      http://www.twistedoak.com/
Winery Blog             http://www.elbloggotorcido.com/
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

KK7P
> NOW I am totally confused!!!

I am not saying they will change, I am saying they were designed to
support general purpose usage. You will *not* need to disconnect data
mode cabling to operate in CW or SSB or AM or FM or...

Sorry, I should have taken this private.

Lyle

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

RE: N6XI NAQP RTTY July, 2007 with K3

Grant Youngman
In reply to this post by Tom Hammond-2
> I'd much prefer to have this sort of thing external to the rig and
> just use them to KEY the dedicated input on the rig.

Couldn't agree more.  I think this stuff is made integral, even if barely
usable in any other than a "lets see if this really works" mode, to get the
blood heated up, feed the hype, and little else.

It's pointless and generally exceptionally poor in performance compared to a
simple PC and external software option, which virtually anyone owning the
radio has access to for essentially no money.  

But you can tell from this thread (and old threads on the 7800 list for
example), that this sort of think is seen as a "wow factor", even if it
turns out in the end to be little more than artificial flavor in the icing.
I don't know why the developers waste their time, other than at the behest
of the marketing department.

Grant/NQ5T

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Tom Hammond-2
In reply to this post by Jeff Stai
Jeff:

>And I'm afraid my skill set has never been up to the micro-surgery
>required to build circuits inside a connector shell.... a much
>better place for circuits is safely inside the chassis.

Please allow me to direct your attention to:

   http://www.n0ss.net/lpt_keying_adapter.pdf

Though this uses the LPT port, a similar PC board could be readily
designed to allow for building a similar circuit into the serial
port connector... you DO still do PC boards, right?   <G>

73,

Tom   N0SS

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

wayne burdick
Administrator
In reply to this post by Jeff Stai
Jeff,

The K3's I/O module already provides for the use of RTS or DTR for PTT
and/or CW KEY in (two separate control lines). The exception is FSK,
which is on the ACC connector. In the present incarnation, driving this
line from a PC requires two external parts (one garden-variety NPN
transistor and one resistor). I used MMTTY with this interface during
NAQP this weekend.

But one nice thing about the K3 is its modularity. Both the main I/O
card and its audio and digital daughter boards can be easily changed to
meet future needs. If for example we added an FSK interface to the
digital daughter board, you'd be able to upgrade it very inexpensively,
and installing it would take about 2 minutes.

Also, we plan to design an external general-purpose I/O unit that would
connect to the ACC jack. It would provide pre-wired connectors for use
with various PC interfaces, transverters, the KRC2, etc.

73,
Wayne
N6KR


---

http://www.elecraft.com

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: N6XI NAQP RTTY July, 2007 with K3

Jeff Stai

hi Wayne - thanks for the reply! I understand now what you're dealing with... the GPIO sounds like a
cool way to get several different interfaces off the back panel of the radio.

I guess I just joined the ranks of those who just can't wait for their K3 and then spew all over the
reflector about it... I blame the fact I had to shlep a 70 pound radio one more time to the station
I guest-operated at yesterday...;)

thanks, and apologies to everyone! - jeff wk6i

ps: one each transistor and resistor in a DB9 shell is in my skill set, two each are right out!


wayne burdick wrote:

> Jeff,
>
> The K3's I/O module already provides for the use of RTS or DTR for PTT
> and/or CW KEY in (two separate control lines). The exception is FSK,
> which is on the ACC connector. In the present incarnation, driving this
> line from a PC requires two external parts (one garden-variety NPN
> transistor and one resistor). I used MMTTY with this interface during
> NAQP this weekend.
>
> But one nice thing about the K3 is its modularity. Both the main I/O
> card and its audio and digital daughter boards can be easily changed to
> meet future needs. If for example we added an FSK interface to the
> digital daughter board, you'd be able to upgrade it very inexpensively,
> and installing it would take about 2 minutes.
>
> Also, we plan to design an external general-purpose I/O unit that would
> connect to the ACC jack. It would provide pre-wired connectors for use
> with various PC interfaces, transverters, the KRC2, etc.
>
> 73,
> Wayne
> N6KR
>
>
> ---
>
> http://www.elecraft.com
>
>
>


--
Jeff Stai               [hidden email]
Twisted Oak Winery      http://www.twistedoak.com/
Winery Blog             http://www.elbloggotorcido.com/
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: Re: N6XI NAQP RTTY July, 2007 with K3

Don Wilhelm-3
In reply to this post by wayne burdick
Wayne,

You might want to bump up that parts count to 3 - and add a diode from
the base to the emitter of that transistor (cathode toward the base) -
protects the transistor from damage on the most negative excursion of
the RS232 signal line which can go to 25 volts negative by the RS232 spec.

There is not likely to be a problem when driving from a PC serial port
because the PC usually does not drive that far negative, but just the
same, I like to have things that work over the full range of the spec
rather than work in most situations.

73,
Don W3FPR

wayne burdick wrote:
> Jeff,
>
> The K3's I/O module already provides for the use of RTS or DTR for PTT
> and/or CW KEY in (two separate control lines). The exception is FSK,
> which is on the ACC connector. In the present incarnation, driving this
> line from a PC requires two external parts (one garden-variety NPN
> transistor and one resistor). I used MMTTY with this interface during
> NAQP this weekend.
>
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: Re: N6XI NAQP RTTY July, 2007 with K3

wayne burdick
Administrator
Can't hurt, Don, thanks. Of course the base limiting resistor will
generally protect the transistor from excessive zener current when it's
in Vbe breakdown.

Wayne


On Jul 22, 2007, at 12:57 PM, Don Wilhelm wrote:

> Wayne,
>
> You might want to bump up that parts count to 3 - and add a diode from
> the base to the emitter of that transistor (cathode toward the base) -
> protects the transistor from damage on the most negative excursion of
> the RS232 signal line which can go to 25 volts negative by the RS232
> spec.
>
> There is not likely to be a problem when driving from a PC serial port
> because the PC usually does not drive that far negative, but just the
> same, I like to have things that work over the full range of the spec
> rather than work in most situations.
>
> 73,
> Don W3FPR
>
> wayne burdick wrote:
>> Jeff,
>> The K3's I/O module already provides for the use of RTS or DTR for
>> PTT and/or CW KEY in (two separate control lines). The exception is
>> FSK, which is on the ACC connector. In the present incarnation,
>> driving this line from a PC requires two external parts (one
>> garden-variety NPN transistor and one resistor). I used MMTTY with
>> this interface during NAQP this weekend.
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>
>

---

http://www.elecraft.com

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

12