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K3 Antenna static bleed

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k6dgw

K3 Antenna static bleed

Forgive me, I'm having a hard time with the schematic:

Does my K3 have an RF choke or a high value resistor across the antenna
input[s] to bleed the static charge? For some reason, I'm getting more
precip static than I usually do. At N6A in Alpine County for the 2009
Cal QSO Party, we managed to fry the front ends of two ICOM 756 PRO II's
from what seemed to be inconsequential snow static. Don't want that to
happen to my K3.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org
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Dick Dievendorff

Re: K3 Antenna static bleed

I see them on the KAT3 schematic, at the top left. There's a 560K resistor
to ground as well as a carrier operated relay (COR) to deal with high input
for each of the two antenna connectors.

The KANT3 has a similar COR (and a similar resistor), again at the top left
of the KANT3 schematic.

73 de Dick, K6KR

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Fred Jensen
Sent: Thursday, February 24, 2011 7:26 PM
To: Elecraft Reflector
Subject: [Elecraft] K3 Antenna static bleed

Forgive me, I'm having a hard time with the schematic:

Does my K3 have an RF choke or a high value resistor across the antenna
input[s] to bleed the static charge? For some reason, I'm getting more
precip static than I usually do. At N6A in Alpine County for the 2009 Cal
QSO Party, we managed to fry the front ends of two ICOM 756 PRO II's from
what seemed to be inconsequential snow static. Don't want that to happen to
my K3.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org
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Robert Friess

Re: K3 Antenna static bleed

Also, spark gaps.

Bob

On Thu, Feb 24, 2011 at 7:50 PM, Dick Dievendorff <[hidden email]>wrote:

> I see them on the KAT3 schematic, at the top left. There's a 560K resistor
> to ground as well as a carrier operated relay (COR) to deal with high input
> for each of the two antenna connectors.
>
> The KANT3 has a similar COR (and a similar resistor), again at the top left
> of the KANT3 schematic.
>
> 73 de Dick, K6KR
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of Fred Jensen
> Sent: Thursday, February 24, 2011 7:26 PM
> To: Elecraft Reflector
> Subject: [Elecraft] K3 Antenna static bleed
>
> Forgive me, I'm having a hard time with the schematic:
>
> Does my K3 have an RF choke or a high value resistor across the antenna
> input[s] to bleed the static charge? For some reason, I'm getting more
> precip static than I usually do. At N6A in Alpine County for the 2009 Cal
> QSO Party, we managed to fry the front ends of two ICOM 756 PRO II's from
> what seemed to be inconsequential snow static. Don't want that to happen
> to
> my K3.
>
> 73,
>
> Fred K6DGW
> - Northern California Contest Club
> - CU in the 2011 Cal QSO Party 1-2 Oct 2011
> - www.cqp.org
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Please help support this email list: http://www.qsl.net/donate.html
>

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ussv dharma

ham radio delux

I am unable to get to a ham radio delux site.....keep getting an error message from something like netnuke.net or whatever.

can anyone access the ham radio delux site?

Grandmaw susan

If you don't change direction you WILL arrive exactly where you're headed!! Susan Meckley, Skipper W7KFI-mm AFA9SM USSV DHARMA

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Roger de Valle

Re: ham radio delux

Works fine from VK

Roger VK3ADE

On 25/02/2011 15:59, ussv dharma wrote:

> I am unable to get to a ham radio delux site.....keep getting an error message from something like netnuke.net or whatever.
>
>
> can anyone access the ham radio delux site?
>
> Grandmaw susan
>
> If you don't change direction you WILL arrive exactly where you're headed!! Susan Meckley, Skipper W7KFI-mm AFA9SM USSV DHARMA
>
>
>
> ______________________________________________________________
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--
Genette Pty Ltd
0407 320 121
03 5330 3081

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Don Wilhelm-4

Re: K3 Antenna static bleed

In reply to this post by k6dgw

Fred,

While the K3 has static protective devices that have been mentioned by
others, I prefer to err on the side of caution. The UHF connector has
one problem for antenna/feedline static charge - if the antenna has
built up a static charge, when the feedline is connected to an SO-239
jack, the center conductor makes contact first, followed by the shield.
So the best solution is a DC path provided within the antenna/feedline
system itself rather than relying on any protection in the K3.

Type N and BNC connectors do it differently, the shield is connected
prior to the center conductor, thus allowing any charge on the feedline
to be safely discharged through the radio's protective devices. With
UHF connectors, the radio's protective devices may not work because only
the center conductor of the feedline is connected, and there is no
return path to the coax shield until the shell is properly tightened.

With UHF connectors, any "antenna disconnection" would best be done
using an antenna switch rather than a physical disconnection. The
disconnect will cause no harm, but the re-connection can do damage
without warning. The antenna switch itself is a good place to provide
that DC return path - either an RF Choke (100 uHy) or a high value
resistor (500k to 1 megohm) between the center conductor and ground of
the common connection to the transceiver. When the transceiver is not
in use, switching to a dummy load is a prudent thing to do, so if you
have 5 antennas to switch, a 6 position switch is best with a dummy load
connected to the 6th position.

Note that this is applicable to any transceiver - I know the question
was asked about the K3 specifically.

73,
Don W3FPR

On 2/24/2011 10:25 PM, Fred Jensen wrote:

> Forgive me, I'm having a hard time with the schematic:
>
> Does my K3 have an RF choke or a high value resistor across the antenna
> input[s] to bleed the static charge? For some reason, I'm getting more
> precip static than I usually do. At N6A in Alpine County for the 2009
> Cal QSO Party, we managed to fry the front ends of two ICOM 756 PRO II's
> from what seemed to be inconsequential snow static. Don't want that to
> happen to my K3.
>
> 73,
>
> Fred K6DGW
>

Don Wilhelm-4

Re: ham radio delux

In reply to this post by ussv dharma

Susan,

No problem here - try http://www.ham-radio-deluxe.com/Home.aspx

73,
Don W3FPR

On 2/24/2011 11:59 PM, ussv dharma wrote:

AC7AC

Re: K3 Antenna static bleed

In reply to this post by Don Wilhelm-4

CONTENTS DELETED

The author has deleted this message.

Vic K2VCO

Re: K3 Antenna static bleed

My coax feeds all go through an entry panel on which are mounted ICE lightning protection
devices. These provide a DC ground on the antenna side and no DC path to the rig. My
open-wire feedline has a pair of 500K resistors to ground. Finally, I have a relay box
which selects the antenna per band and is driven by a KRC2. Those relays default to ground
the rig input when the power is off.

On 2/24/2011 10:23 PM, Ron D'Eau Claire wrote:

> When my antenna is disconnected (as it always is when I'm not operating) it
> is connected to an earth ground.
>
> Ron AC7AC
>
> -----Original Message-----
> Fred,
>
> While the K3 has static protective devices that have been mentioned by
> others, I prefer to err on the side of caution. The UHF connector has
> one problem for antenna/feedline static charge - if the antenna has
> built up a static charge, when the feedline is connected to an SO-239
> jack, the center conductor makes contact first, followed by the shield.
> So the best solution is a DC path provided within the antenna/feedline
> system itself rather than relying on any protection in the K3.
>
> Type N and BNC connectors do it differently, the shield is connected
> prior to the center conductor, thus allowing any charge on the feedline
> to be safely discharged through the radio's protective devices. With
> UHF connectors, the radio's protective devices may not work because only
> the center conductor of the feedline is connected, and there is no
> return path to the coax shield until the shell is properly tightened.
>
> With UHF connectors, any "antenna disconnection" would best be done
> using an antenna switch rather than a physical disconnection. The
> disconnect will cause no harm, but the re-connection can do damage
> without warning. The antenna switch itself is a good place to provide
> that DC return path - either an RF Choke (100 uHy) or a high value
> resistor (500k to 1 megohm) between the center conductor and ground of
> the common connection to the transceiver. When the transceiver is not
> in use, switching to a dummy load is a prudent thing to do, so if you
> have 5 antennas to switch, a 6 position switch is best with a dummy load
> connected to the 6th position.
>
> Note that this is applicable to any transceiver - I know the question
> was asked about the K3 specifically.
>
> 73,
> Don W3FPR
>
> ______________________________________________________________
> 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

--
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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Phil Salas

Re: K3 Antenna static bleed

In reply to this post by Don Wilhelm-4

"...While the K3 has static protective devices that have been mentioned by
others, I prefer to err on the side of caution. ...The UHF connector has
one problem for antenna/feedline static charge - if the antenna has built up
a static charge, when the feedline is connected to an SO-239 jack, the
center conductor makes contact first, followed by the shield. So the best
solution is a DC path provided within the antenna/feedline system itself
rather than relying on any protection in the K3... 73, Don W3FPR"

I completely agree with Don. For any of my antennas that aren't normally DC
grounded (like with a gamma match or a balun), I permanently mount a high
value resistor directly across the antenna feedpoint to keep the antenna
discharged. This will also help protect your SWR Analyzer when you hook-up
to the antenna to make measurements. I also have a MFJ-4726 antenna switch
in the shack that grounds unused inputs (and all inputs when not powered),
and ICE in-line arrestors at the feedline entrance.

Phil - AD5X

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kcflyers

Re: K3 Antenna static bleed

For many years I have placed a 100K or so resistor across antenna leads at the antenna. For example with a dipole, right across the point where coax or window line is connected. Besides dealing with static pickup, it's a easy way to do a check of antenna and coax. Put VOM across feedline in shack. Should measure 100K. If open, bad connection somewhere. If less than 100K, water leakage into coax, short, or something else wrong. John.

N7US

Re: K3 Antenna static bleed

In reply to this post by Don Wilhelm-4

I have an Alpha Delta grounding switch with the arc plug as the first piece
of equipment in the shack after the cable (just one HF/6M antenna line). It
is in line after ICE arrestors which have static drains, one at the base of
the tower and another on my grounding panel at the entrance to the house.

Additionally, I have a DX Engineering remote antenna switch at the top of
the tower that grounds all antennas when it is off.

I switch the Alpha Delta to ground when I shut down for the night. I
disconnect it and everything else from the antenna during local lightning
storms.

Last April, I foolishly didn't disconnect because I didn't think the storm
was that close. I didn't have the Alpha Delta in line, and a major strike
was pretty painful but instructive!

Jim N7US

-----Original Message-----
While the K3 has static protective devices that have been mentioned by
others, I prefer to err on the side of caution. The UHF connector has
one problem for antenna/feedline static charge - if the antenna has
built up a static charge, when the feedline is connected to an SO-239
jack, the center conductor makes contact first, followed by the shield.
So the best solution is a DC path provided within the antenna/feedline
system itself rather than relying on any protection in the K3.

Type N and BNC connectors do it differently, the shield is connected
prior to the center conductor, thus allowing any charge on the feedline
to be safely discharged through the radio's protective devices. With
UHF connectors, the radio's protective devices may not work because only
the center conductor of the feedline is connected, and there is no
return path to the coax shield until the shell is properly tightened.

With UHF connectors, any "antenna disconnection" would best be done
using an antenna switch rather than a physical disconnection. The
disconnect will cause no harm, but the re-connection can do damage
without warning. The antenna switch itself is a good place to provide
that DC return path - either an RF Choke (100 uHy) or a high value
resistor (500k to 1 megohm) between the center conductor and ground of
the common connection to the transceiver. When the transceiver is not
in use, switching to a dummy load is a prudent thing to do, so if you
have 5 antennas to switch, a 6 position switch is best with a dummy load
connected to the 6th position.

Note that this is applicable to any transceiver - I know the question
was asked about the K3 specifically.

73,
Don W3FPR

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