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K3 - MMTTY interface for FSK

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N2TK

K3 - MMTTY interface for FSK

I am having brain freeze. I must have changed something but not sure what.
Both K3's had been working fine on FSK using MMTTY for years. I can still
receive fine, but I can't transmit on either.

I am using LP Bridge which is talking fine to either K3.

When I hit Xmit in MMTTY the program shows it is sending, but it does not
key the K3.

All along I have been using COM 1 on my PC for FSK keying. I have been using
pin 3 to Pin 1 on the Acc K3 socket. I have not used Pin 7 (PTT) to Pin 4 on
the K3.

When I measure voltage on Com 1 pin 3 it is -9V. When I hit Xmit in MMTTY it
stays at -9V.

MMTTY is setup as follows:

- Misc tab - COM-TxD (FSK)

- TX tab - Port Com1.

- I am not using Radio Command

K3

- PTT-KEY is OFF-OFF.

One K3 has KIO3A using RS232. The other has KIO3B using USB.

Also if I ground pin 4 on the Acc socket it does not transmit.

Tried another Com port and made the change in MMTTY but the same result.

What could I have inadvertently changed so that the Com 1 Pin 3 to stay at
-9V?

Tnx for any feedback.

N2TK, Tony

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Don Wilhelm

Re: K3 - MMTTY interface for FSK

Tony,

If the com port pin stays at -9volts, then the COM port is not "doing
its thing".
I trust you used a 'scope to look measure it. A DMM will not likely
respond quickly enough to see the positive going pulses.
Try another COM port.

73,
Don W3FPR

On 7/14/2016 10:45 AM, N2TK, Tony wrote:

Joe Subich, W4TV-4

Re: K3 - MMTTY interface for FSK

In reply to this post by N2TK

> All along I have been using COM 1 on my PC for FSK keying. I have
> been using pin 3 to Pin 1 on the Acc K3 socket. I have not used Pin
> 7 (PTT) to Pin 4 on the K3.

I trust you have been using an NPN transistor between the RS-232 output
(+/- 9V) of the serial port and the TTL input (0 to +5V) of the K3 ACC
port.

If you are not using Radio Command and have not connected Pin 7 of the
serial port to pin 4 of the K3 (again using an NPN transistor), I do
not know how the K3 would ever switch to transmit.

73,

... Joe, W4TV

On 7/14/2016 10:45 AM, N2TK, Tony wrote:

> I am having brain freeze. I must have changed something but not sure what.
> Both K3's had been working fine on FSK using MMTTY for years. I can still
> receive fine, but I can't transmit on either.
>
> I am using LP Bridge which is talking fine to either K3.
>
> When I hit Xmit in MMTTY the program shows it is sending, but it does not
> key the K3.
>
>
>
> All along I have been using COM 1 on my PC for FSK keying. I have been using
> pin 3 to Pin 1 on the Acc K3 socket. I have not used Pin 7 (PTT) to Pin 4 on
> the K3.
>
> When I measure voltage on Com 1 pin 3 it is -9V. When I hit Xmit in MMTTY it
> stays at -9V.
>
>
>
> MMTTY is setup as follows:
>
> - Misc tab - COM-TxD (FSK)
>
> - TX tab - Port Com1.
>
> - I am not using Radio Command
>
>
>
> K3
>
> - PTT-KEY is OFF-OFF.
>
> One K3 has KIO3A using RS232. The other has KIO3B using USB.
>
>
>
> Also if I ground pin 4 on the Acc socket it does not transmit.
>
> Tried another Com port and made the change in MMTTY but the same result.
>
> What could I have inadvertently changed so that the Com 1 Pin 3 to stay at
> -9V?
>
>
>
> Tnx for any feedback.
>
> N2TK, Tony
>
> ______________________________________________________________
> 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
> Message delivered to [hidden email]
>

N2TK

Re: K3 - MMTTY interface for FSK

W4TV and W3FPR got me down the right path.

I forgot that it is a pulse on RS232 pin1. Got the scope out and it is fine.
Thanks Don. Got to get me one of those small, lightweight scopes.

I had both transistors in the RS232 shell (FSK keying and PTT) and when I
opened the shell it looked like I had not hooked up the transistor to pin4
of the Acc plug. Actually I must have cold soldered the lead and it broke
free after several years. When I first looked at the lead it seemed I had
unsoldered the lead and insulated it. That is why I had thought I was keying
without the PTT. But as Joe pointed out, no way.

Back in business. Thanks for the help.

73,
N2TK, Tony

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Joe
Subich, W4TV
Sent: Thursday, July 14, 2016 11:30 AM
To: [hidden email]
Subject: Re: [Elecraft] K3 - MMTTY interface for FSK

> All along I have been using COM 1 on my PC for FSK keying. I have been
> using pin 3 to Pin 1 on the Acc K3 socket. I have not used Pin
> 7 (PTT) to Pin 4 on the K3.

I trust you have been using an NPN transistor between the RS-232 output
(+/- 9V) of the serial port and the TTL input (0 to +5V) of the K3 ACC port.

If you are not using Radio Command and have not connected Pin 7 of the
serial port to pin 4 of the K3 (again using an NPN transistor), I do not
know how the K3 would ever switch to transmit.

73,

... Joe, W4TV

On 7/14/2016 10:45 AM, N2TK, Tony wrote:

> I am having brain freeze. I must have changed something but not sure what.
> Both K3's had been working fine on FSK using MMTTY for years. I can
> still receive fine, but I can't transmit on either.
>
> I am using LP Bridge which is talking fine to either K3.
>
> When I hit Xmit in MMTTY the program shows it is sending, but it does
> not key the K3.
>
>
>
> All along I have been using COM 1 on my PC for FSK keying. I have been
> using pin 3 to Pin 1 on the Acc K3 socket. I have not used Pin 7 (PTT)
> to Pin 4 on the K3.
>
> When I measure voltage on Com 1 pin 3 it is -9V. When I hit Xmit in
> MMTTY it stays at -9V.
>
>
>
> MMTTY is setup as follows:
>
> - Misc tab - COM-TxD (FSK)
>
> - TX tab - Port Com1.
>
> - I am not using Radio Command
>
>
>
> K3
>
> - PTT-KEY is OFF-OFF.
>
> One K3 has KIO3A using RS232. The other has KIO3B using USB.
>
>
>
> Also if I ground pin 4 on the Acc socket it does not transmit.
>
> Tried another Com port and made the change in MMTTY but the same result.
>
> What could I have inadvertently changed so that the Com 1 Pin 3 to
> stay at -9V?
>
>
>
> Tnx for any feedback.
>
> N2TK, Tony
>
> ______________________________________________________________
> 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 Message delivered to
> [hidden email]
>

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

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Please help support this email list: http://www.qsl.net/donate.html Message
delivered to [hidden email]

______________________________________________________________
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
Message delivered to [hidden email]