"ant err pr flt" error message?? also antenna adjacency problem??

[jsdroyster]

Hello all, we just got back our KX3 after under-warranty repair.
The technician included a message that the parts he replaced were usually
damaged if
1) Connected to an antenna during a thunderstorm (nope, not here)
2) Power over 100 watts on "an adjacent antenna"
               
QUESTION 1:  The KX3 has been using an inverted V wire antenna.  At its
closest point to a vertical antenna for our K3 they are about 30 feet apart.
Is this too close?  How far away would be far enough if K3 operator were
using 450 watts?    I do recall one morning when I used K3 while Larry had
KX3 on.  I guess I will never do that again, but I would like to know what
distance is safe.  We have a neighbor a block away who runs high power.

QUESTION 2:  I just set the KX3 back up with KXPA100.  When Larry
transmitted at 5 watts all was OK but when he transmitted at 40 watts it
said "ANT ERR"  at the top of the screen and "PR FLT" at the bottom.
I checked the connections.  I checked the SWR of the antenna with a SWR
meter.  What do these messages mean (as they are not described in the
manual)?
Could these messages have to do with the KXPA100?

THANKS to anyone who can opine.
73,
Julie KT4JR



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[ejkkjh]

Julie,
Question 1 is good question, and I am interested in the answers.
I sometimes run the KX3 and the K3 with KPA500 at the same time, on
different bands and antennas but the antennas are fairly close together.
I don’t do this often, and so far no problems, but it had not occurred to me
this would be a problem?
Emory  WM3M

-----Original Message-----
From: Julie Royster
Sent: Tuesday, April 15, 2014 9:33 AM
To: [hidden email]
Subject: [Elecraft] "ant err pr flt" error message?? also antenna
adjacencyproblem??

Hello all, we just got back our KX3 after under-warranty repair.
The technician included a message that the parts he replaced were usually
damaged if
1) Connected to an antenna during a thunderstorm (nope, not here)
2) Power over 100 watts on "an adjacent antenna"

QUESTION 1:  The KX3 has been using an inverted V wire antenna.  At its
closest point to a vertical antenna for our K3 they are about 30 feet apart.
Is this too close?  How far away would be far enough if K3 operator were
using 450 watts?    I do recall one morning when I used K3 while Larry had
KX3 on.  I guess I will never do that again, but I would like to know what
distance is safe.  We have a neighbor a block away who runs high power.

QUESTION 2:  I just set the KX3 back up with KXPA100.  When Larry
transmitted at 5 watts all was OK but when he transmitted at 40 watts it
said "ANT ERR"  at the top of the screen and "PR FLT" at the bottom.
I checked the connections.  I checked the SWR of the antenna with a SWR
meter.  What do these messages mean (as they are not described in the
manual)?
Could these messages have to do with the KXPA100?

THANKS to anyone who can opine.
73,
Julie KT4JR



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[Toby Pennington]

Nr 2........Be very careful using 500 watts out on a vertical only 30
feet away to the "v" antenna of your KX3 as you will blow out the front
end on the radio,  usually diodes etc.  The best thing to do is to
disconnect the antenna of the rig not being used.  Voltage can come in
on your antennas and sometimes it take only a few volts to cause problems.

I believe Elecraft use some protection at the front end,  but not a
lot.  Someone else may know more about this.  I have been there and do
that so know first hand the trouble you can get into.

Toby  K4NH


On 4/15/2014 9:33 AM, Julie Royster wrote:

> Hello all, we just got back our KX3 after under-warranty repair.
> The technician included a message that the parts he replaced were usually
> damaged if
> 1) Connected to an antenna during a thunderstorm (nope, not here)
> 2) Power over 100 watts on "an adjacent antenna"
>
> QUESTION 1:  The KX3 has been using an inverted V wire antenna.  At its
> closest point to a vertical antenna for our K3 they are about 30 feet apart.
> Is this too close?  How far away would be far enough if K3 operator were
> using 450 watts?    I do recall one morning when I used K3 while Larry had
> KX3 on.  I guess I will never do that again, but I would like to know what
> distance is safe.  We have a neighbor a block away who runs high power.
>
> QUESTION 2:  I just set the KX3 back up with KXPA100.  When Larry
> transmitted at 5 watts all was OK but when he transmitted at 40 watts it
> said "ANT ERR"  at the top of the screen and "PR FLT" at the bottom.
> I checked the connections.  I checked the SWR of the antenna with a SWR
> meter.  What do these messages mean (as they are not described in the
> manual)?
> Could these messages have to do with the KXPA100?
>
> THANKS to anyone who can opine.
> 73,
> Julie KT4JR
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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> Message delivered to [hidden email]

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[k6dgw]

On 4/15/2014 6:33 AM, Julie Royster wrote:
       
> QUESTION 1:  The KX3 has been using an inverted V wire antenna.  At its
> closest point to a vertical antenna for our K3 they are about 30 feet apart.
> Is this too close?

Probably.  Conductors in the near field of an antenna essentially become
part of the antenna, like parasitic elements an in a yagi, and can carry
a major fraction of the power delivered to the antenna.  30 feet is 1/4
wave at 40 meters.

> How far away would be far enough if K3 operator were
> using 450 watts?

It depends on frequency and size of the antennae, and to some extent
orientation of the two, however polarization in the near field isn't a
huge factor.  Several wavelengths is probably a good place to start.
>
> QUESTION 2:  I just set the KX3 back up with KXPA100.  When Larry
> transmitted at 5 watts all was OK but when he transmitted at 40 watts it
> said "ANT ERR"  at the top of the screen and "PR FLT" at the bottom.
> I checked the connections.  I checked the SWR of the antenna with a SWR
> meter.  What do these messages mean (as they are not described in the
> manual)?
> Could these messages have to do with the KXPA100?

Don't know, don't have a KX3 or KXPA100.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org

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[Edward R Cole]

This has been discussed recently so there may be something in the
reflector archive.

Space loss formula are for far-field situations:
Pn = 32.4 + 20Log(F) + 20Log(d), where Pn is in dBm, F in MHz, d in km

Antennas as close as you have are in the antenna near-field which has
much more complicated math which I am not going to attempt.  So the
only way to determine what is safe is to measure power coming in on
the KX3 antenna when you transmit with the K3 (plus amp) on the other
antenna running whatever power you plan to use.

I know many hams do not own a lot of sophisticated test equipment so
I offer three ways to make the measurement:

1-  A simple method would be to connect an ordinary power meter (SWR
meter) to the KX3 antenna and connect the other connector to a load
(no radio connected).  Connect so you read forward power toward the
load.  I'm going to assume your meter is capable of measuring 10w
full scale so a small movement of the indicator would show about 1%
(0.1w) indication.  That level is 100mw which is about 100 times too
strong for the KX3 receiver to survive.  In fact maybe the KX3 can
handle 10mw but better to be safe by using 1mw as the maximum safe
input power limit.

2-  One can measure weaker signals if you could obtain use of a HP432
microwave power meter as it measures from -20 to +10 dBm* (but will
burn out above this range).  Probably you would want the owner of the
meter to run the test since they are expensive and delicate.  *0.001
to 10mw; attenuators should be used initially like, below.

3-  If you have access to some coaxial attenuators you could place
them inline with the antenna and your receiver and see what s-meter
reading results.  I would start with at least 40-dB for safety for
your radio (KX3 in your case).  if s-meter readings are too low then
remove attenuation in 10-dB steps until you see full scale reading of
the s-meter.  At this point if you still have any attenuation in the
line then the power coming into your antenna is too strong for the radio.

For reference my KX3 reads S9+50 with a 0 dBm (1mw) signal from my
XG3 on 20-MHz (with PRE off).

I have a similar situation with 80/40m inverted-V hung on the same
tower as my triband yagi with apex about 12 feet below the yagi.  I
have a 6m yagi at 30-feet below and often monitor 6m while using my
K3 on HF bands (that seems to be OK but not running the K3+125w amp
to the other 6m yagi 50-feet horizontally distant).
------------------------
QUESTION 1:  The KX3 has been using an inverted V wire antenna.  At its
closest point to a vertical antenna for our K3 they are about 30 feet apart.
Is this too close?  How far away would be far enough if K3 operator were
using 450 watts?    I do recall one morning when I used K3 while Larry had
KX3 on.  I guess I will never do that again, but I would like to know what
distance is safe.  We have a neighbor a block away who runs high power.

THANKS to anyone who can opine.
73,
Julie KT4JR


73, Ed - KL7UW
http://www.kl7uw.com
     "Kits made by KL7UW"
Dubus Mag business:
     [hidden email]

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[Stan Gibbs, KR7C]

If you want to understand the inter-radio interference issues you face, the potential for damage they may cause, techniques to measure their magnitude, and measures you can take to minimize them, I suggest you get a copy of "Managing Interstation Interference" by George Cutsogeorge, W2VJN.  It is available on the web from Inrad.

There is a very useful section toward the back about using the station radios themselves to measure the interference.

[Merv Schweigert]

Noticed this morning when turning on the K3 for the first time after
being off all night,  that the fans were on and changing speed
rapidly.  The fan would run between low and the 3rd speed back
and forth.
Checking the PA temp it was jumping from 25C to 60C back and
forth,  thus the reason the fans were doing the same.   It did this
for about 2 minutes and then went into normal no fan mode.
Anyone had something like this happen?  Bad sensor?  The radio
had just been turned on so could not have been up to 60C temp
indicated.
Never use more than 35 watts power as I drive an amp all the time,

Thanks  73 Merv K9FD/KH6

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[Eric Buggee; VK3AX]

     Hi all,

     I have had exactly the same problem on my K3 (4520) It is
intermittent and ahs been that way fo a couple of years! Not causing any
operational issues except for 160M AM net when it causes the K3 to drop
back to 5 watts use it to drive a linear with the power out set to
equivalent of 50 Watts.

     f the fellows at Elecraft service can shed some light on the
problem I would appreciate any guidance.  I have had the 100Watt Pa out
a couple of times but nothing looks untoward.

     BTW, I have been having "ERR12V" displayed a few times ! and the
pins for the PA power feed are the gold plated type.  Any suggestions or
comments offered will be appreciated.

     73,

     Eric VK3AX.



On 4/17/2014 1:55 AM, Merv Schweigert wrote:

> Noticed this morning when turning on the K3 for the first time after
> being off all night,  that the fans were on and changing speed
> rapidly.  The fan would run between low and the 3rd speed back
> and forth.
> Checking the PA temp it was jumping from 25C to 60C back and
> forth,  thus the reason the fans were doing the same.   It did this
> for about 2 minutes and then went into normal no fan mode.
> Anyone had something like this happen?  Bad sensor?  The radio
> had just been turned on so could not have been up to 60C temp
> indicated.
> Never use more than 35 watts power as I drive an amp all the time,
>
> Thanks  73 Merv K9FD/KH6
>
> ______________________________________________________________
> Elecraft mailing list
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>
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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