K2/100 Locking Up in Data Mode

[Jim Campbell]

I'm playing with JT65-HF. I have no problem with reception. When I send
a message (48 seconds of key-down at 5 W) the message is sent correctly
but after transmission stops the front panel controls are frozen. By
frozen I mean that the only control that is effective on the front panel
is the power switch. The dial doesn't change the frequency and all
switch depressions are ignored.

I built my own interface. The two audio lines (from radio to sound card
and from sound card to radio are decoupled with small Radio Shack audio
transformers. The keying line from the USB to serial dongle uses an
opto-isolator for the decoupling. The audio level for the sound card to
radio circuit is adjustable with a small potentiometer and is adjusted
so the ALC just blinks the first bar. The data mode is enabled so that I
see an "r" with a bar over it as the mode.

All my radio gear uses 12 VDC and the 12 V side of the supply is
isolated from the house ground. I have an 8 ft rod driven in the ground
outside the radio room and all the antennas (coax shields) and -12 V are
bonded to this ground.

Any help will be appreciated.

72,

Jim - W4BQP

--
Jim Campbell

When seconds count, the police
are just minutes away.

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[Jim Campbell]

I discovered my problem. I hadn't constructed my opto-isolator device
properly. I was using a standard circuit but a standard circuit wasn't
designed for a K2. Once keyed, the K2 never returned to receive.

For the K2 to work correctly I had to add two diodes to the output of
the opto-isolator and let the K2 auto-detect its presence. I found this
by carefully reading the part of the K2 manual that tells how to
interface it with a computer. The appropriate circuit is shown in Fig.
8-1 on page 99 of the K2 Manual.

I successfully worked Holland, Ireland and a couple of stations in the
US this evening using JT65-HF and 5 watts on 17 M. That's special to me
because of the antenna that I am using. It is an 88 ft. dipole being fed
by ladder line and averaging 12 ft. above the ground. It is also running
through several tree canopies. Truly amazing! Thanks Elecraft for such a
nice rig.

72,

Jim - W4BQP
K2/100 #2268 w/ 100W ATU

On 5/28/2012 12:10 AM, Jim Campbell wrote:

> I'm playing with JT65-HF. I have no problem with reception. When I send
> a message (48 seconds of key-down at 5 W) the message is sent correctly
> but after transmission stops the front panel controls are frozen. By
> frozen I mean that the only control that is effective on the front panel
> is the power switch. The dial doesn't change the frequency and all
> switch depressions are ignored.
>
> I built my own interface. The two audio lines (from radio to sound card
> and from sound card to radio are decoupled with small Radio Shack audio
> transformers. The keying line from the USB to serial dongle uses an
> opto-isolator for the decoupling. The audio level for the sound card to
> radio circuit is adjustable with a small potentiometer and is adjusted
> so the ALC just blinks the first bar. The data mode is enabled so that I
> see an "r" with a bar over it as the mode.
>
> All my radio gear uses 12 VDC and the 12 V side of the supply is
> isolated from the house ground. I have an 8 ft rod driven in the ground
> outside the radio room and all the antennas (coax shields) and -12 V are
> bonded to this ground.
>
> Any help will be appreciated.
>
> 72,
>
> Jim - W4BQP
>

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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