Elecraft › [K3]

kinda like other post K3 turns off.

Classic

List

Threaded

8 messages Options

KC6CNN

kinda like other post K3 turns off.

CONTENTS DELETED

The author has deleted this message.

Rick WA6NHC

Re: kinda like other post K3 turns off.

You're getting RF on the power system. Running with no issues into a dummy load at full power proves this.

Try adding a common mode choke (aka current balun, but that's inaccurate) to your antenna system. If that doesn't help, filter the AC and DC power leads with ferrites (cords wound around ferrite donuts) or move the power supply further from the antenna.

73,
Rick wa6nhc

Tiny iPhone 5 keypad, typos are inevitable

> On Nov 1, 2013, at 9:15 PM, KC6CNN <[hidden email]> wrote:
>
> I just read a message about a K3 that had turned off and he could not get it
> to turn back on.
> I have kinda the same issue but different.
> I have my K3 connected to a Alpha 76pa amp. I operated it for several
> months, then all a sudden I would transmit and the K3 would turn off. It
> would not turn back on until the power supply was turned off and then back
> on. I checked the Astron 35amp power supply and it is not "crow baring" The
> voltage remains good and the SWR are fine. I changed coax cables, and even
> changed antennas. The problem still keeps happening. I changed power
> supplies and it still does it. I lowered the drive power on the K3 to 10
> watts and tuned the Alpha. I was able to up the drive till the power was
> around 300 watts. At 300 watts the K3 turned off again. This is repeatable
> and always turns off around 300 watts. I took the amp to a friend and it
> performed great. I hooked my station up again and took the antenna off and
> ran it into a dummy load and it performed flawlessly. I even had the dummy
> load sitting on the floor between the amp and K3 and it had no issues. I
> have checked and do not get shocked or bitten by anything in the shack. I
> hooked it back up and it still turns off. I am thinking that I might have a
> rf feed back problem, but thought that it would have shown itself when the
> dummy load was sitting close to the K3 at full legal power.
>
> Has anyone had any experiences like this or any suggestions to help me out.
> Thank you
> Gerald
>
>
>
> -----
> KC6CNN - Gerald
> K2 # 5486
> K3 # 6254
> KX3 # 757
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/kinda-like-other-post-K3-turns-off-tp7580359.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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

______________________________________________________________
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

Martin AA6E-3

Re: kinda like other post K3 turns off.

In reply to this post by KC6CNN

Gerald,

What kind of antennas and feedlines (coax?) do you have? Does this happen on all
bands the same way? What modes are you using? It does sound like RF feedback.

If you can't easily move the feedlines and antennas away from the rig, I would start
filtering all the power leads and other wires going into the K3 using #77 or #43
ferrite cores (maybe 8 or 10 turns). Also, check your grounding. Do you have a
single point ground? Is everything well connected to it?

73 Martin AA6E

On 11/02/2013 12:15 AM, KC6CNN wrote:

> I just read a message about a K3 that had turned off and he could not get it
> to turn back on.
> I have kinda the same issue but different.
> I have my K3 connected to a Alpha 76pa amp. I operated it for several
> months, then all a sudden I would transmit and the K3 would turn off. It
> would not turn back on until the power supply was turned off and then back
> on. I checked the Astron 35amp power supply and it is not "crow baring" The
> voltage remains good and the SWR are fine. I changed coax cables, and even
> changed antennas. The problem still keeps happening. I changed power
> supplies and it still does it. I lowered the drive power on the K3 to 10
> watts and tuned the Alpha. I was able to up the drive till the power was
> around 300 watts. At 300 watts the K3 turned off again. This is repeatable
> and always turns off around 300 watts. I took the amp to a friend and it
> performed great. I hooked my station up again and took the antenna off and
> ran it into a dummy load and it performed flawlessly. I even had the dummy
> load sitting on the floor between the amp and K3 and it had no issues. I
> have checked and do not get shocked or bitten by anything in the shack. I
> hooked it back up and it still turns off. I am thinking that I might have a
> rf feed back problem, but thought that it would have shown itself when the
> dummy load was sitting close to the K3 at full legal power.
>
> Has anyone had any experiences like this or any suggestions to help me out.
> Thank you
> Gerald
>
>
>
> -----
> KC6CNN - Gerald
> K2 # 5486
> K3 # 6254
> KX3 # 757
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/kinda-like-other-post-K3-turns-off-tp7580359.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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

KC6CNN

Re: kinda like other post K3 turns off.

CONTENTS DELETED

The author has deleted this message.

Gary Gregory-2

Re: kinda like other post K3 turns off.

ZS6BKW and OCF antennas are notorious for RF feedback.

What construction method is in use for the OCF Balun I wonder. I use a dula
core Balun Designs unit and still at times there is a small amount of RF
feedback seen.

I used a ZS6BKW for several weeks and RF was always problematical.

Gary

On 2 November 2013 14:47, KC6CNN <[hidden email]> wrote:

> The two antennas are a zs6bkw and a OCF dipole. Both are up about 32 feet
> and
> the ends are 12 foot off the ground. The coax is LMR400 and is new. The
> antennas are located on the opposite side of the house from the shack. The
> amp is powered by a 240 volt plug and the power supply is 110 volt.
> This happens in all modes, CW, Voice, Psk31. It happens on all bands. It
> only happens when the power is increased to 300 watts or higher.
> My station ran great for several months 6 to 12 months. Then all of a
> sudden
> this problem showed up.
>
> I will start filtering everything tomorrow to see if that helps.
> Thanks for the replies I will try your suggestions
>
> Gerald
>
>
>
>
> -----
> KC6CNN - Gerald
> K2 # 5486
> K3 # 6254
> KX3 # 757
> --
> View this message in context:
> http://elecraft.365791.n2.nabble.com/kinda-like-other-post-K3-turns-off-tp7580359p7580362.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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
>

--
*Gary - VK1ZZ
Skype: Gary.VK1ZZ
http://www.qsl.net/vk1zz
Motorhome Portable*
*"Grumpy's House"*
*Elecraft K3
KPA500FT
KAT500FT**

*
______________________________________________________________
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

KC6CNN

Re: kinda like other post K3 turns off.

CONTENTS DELETED

The author has deleted this message.

Martin AA6E-3

Re: kinda like other post K3 turns off.

In reply to this post by KC6CNN

If the problem came on suddenly, that suggests a connector or wiring problem. Check
to be sure everything is tight and there are no breaks in the shield, etc.

73 de AA6E

On 11/02/2013 12:47 AM, KC6CNN wrote:

> The two antennas are a zs6bkw and a OCF dipole. Both are up about 32 feet and
> the ends are 12 foot off the ground. The coax is LMR400 and is new. The
> antennas are located on the opposite side of the house from the shack. The
> amp is powered by a 240 volt plug and the power supply is 110 volt.
> This happens in all modes, CW, Voice, Psk31. It happens on all bands. It
> only happens when the power is increased to 300 watts or higher.
> My station ran great for several months 6 to 12 months. Then all of a sudden
> this problem showed up.
>
> I will start filtering everything tomorrow to see if that helps.
> Thanks for the replies I will try your suggestions
>
> Gerald
>
>
>
>
> -----
> KC6CNN - Gerald
> K2 # 5486
> K3 # 6254
> KX3 # 757
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/kinda-like-other-post-K3-turns-off-tp7580359p7580362.html
> Sent from the Elecraft mailing list archive at Nabble.com.
> ______________________________________________________________
> 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

KC6CNN

Re: kinda like other post K3 turns off.

CONTENTS DELETED

The author has deleted this message.