OT: Remote tuner, vertical, and K3 help needed

[Randy Cook]

I have a weird problem that I could use help on.  I have limited experience with antennas, so the answer could be something simple I have overlooked.

I am using a K3/100 with the ATU.  I recently installed a 31 foot vertical antenna with ground radials and a balun at the base. The MFJ analyzer shows an SWR (at my K3) below 1. 3:1 on 40M and near 15M as you would expect.  SWR for the other bands are much higher, about 4:1 for 17, 12, and 10. But, the K3 tuner trims up fine. I understand the efficiency is hit, but it does work. On 20M, the SWR is near 6:1. Again, I can tune it with the K3, but I am not getting out well.  These results are the same with the Electraft BL2 balun OR a DX Engineering line choke installed. There is about 80 feet of LMR-400 between the rig and the antenna.  I also have a static/lightning arrestor in line.

In doing some research, it seems that a remote tuner at the antenna base would be a more efficient system. I purchased a remote tuner kit from DX Engineering, that includes an MFJ 927 tuner at the base (along with a mount and a line choke). I  bypassed the internal K3 tuner.  With the remote tuner in place, the SWR HI message is displayed on my K3 when I try to transmit most of the time, and on all bands.  The tuner was checked out by MFJ under warranty, and came back fine.  I reinstalled it, and have the same problem.

I verified that 12 volts is getting to the tuner.  Bypassing the lightning arrestor makes no difference. Going back to the K3 and no remote tuner works as before.

Elecraft tech support was very helpful as usual.  They did suggest replacing the internal tuner with the passthrough board sold with the base K3 to see if there was some weirdness between the two tuners.  I do not have the correct board, as I bought my rig with the tuner.  

DX Engineering could not help me. I gave up on MFJ.

Does anyone have a similar configuration that is working?

Does anyone have the board that is in place when the ATU is not installed? I would 'rent' it if available for testing.  A new one from Elecraft is about $60.

As this is a bit OT, please respond off line, and I will post any solutions back to the reflector for future reference.

Thanks in advance.

73s

Randy K6CRC
K3#2051
[hidden email]




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[Richard Thorne-3]

Randy,

I do the same thing but I use an SGC-239 tuner at the base of a 43'
vertical.

Try going into the configuration mode of the K3 and set the tune power
to 10 watts.  Pick a frequency and push and hold the xmit/tune button on
the K3 so you'll send 10 watts or less to the mfj tuner to start a tune
cycle.  Once you get an acceptable swr you should be able to transmit at
100 watts.  After you do this on all the bands that you normally operate
on the, the mfj tuner should remember it so quick qsy's are accomplished
without pressing the tune button.  A couple dits from your paddle should
do it there after.

Rich - N5ZC



On 11/9/2011 12:28 PM, Randy Cook wrote:

> I have a weird problem that I could use help on.  I have limited experience with antennas, so the answer could be something simple I have overlooked.
>
> I am using a K3/100 with the ATU.  I recently installed a 31 foot vertical antenna with ground radials and a balun at the base. The MFJ analyzer shows an SWR (at my K3) below 1. 3:1 on 40M and near 15M as you would expect.  SWR for the other bands are much higher, about 4:1 for 17, 12, and 10. But, the K3 tuner trims up fine. I understand the efficiency is hit, but it does work. On 20M, the SWR is near 6:1. Again, I can tune it with the K3, but I am not getting out well.  These results are the same with the Electraft BL2 balun OR a DX Engineering line choke installed. There is about 80 feet of LMR-400 between the rig and the antenna.  I also have a static/lightning arrestor in line.
>
> In doing some research, it seems that a remote tuner at the antenna base would be a more efficient system. I purchased a remote tuner kit from DX Engineering, that includes an MFJ 927 tuner at the base (along with a mount and a line choke). I  bypassed the internal K3 tuner.  With the remote tuner in place, the SWR HI message is displayed on my K3 when I try to transmit most of the time, and on all bands.  The tuner was checked out by MFJ under warranty, and came back fine.  I reinstalled it, and have the same problem.
>
> I verified that 12 volts is getting to the tuner.  Bypassing the lightning arrestor makes no difference. Going back to the K3 and no remote tuner works as before.
>
> Elecraft tech support was very helpful as usual.  They did suggest replacing the internal tuner with the passthrough board sold with the base K3 to see if there was some weirdness between the two tuners.  I do not have the correct board, as I bought my rig with the tuner.
>
> DX Engineering could not help me. I gave up on MFJ.
>
> Does anyone have a similar configuration that is working?
>
> Does anyone have the board that is in place when the ATU is not installed? I would 'rent' it if available for testing.  A new one from Elecraft is about $60.
>
> As this is a bit OT, please respond off line, and I will post any solutions back to the reflector for future reference.
>
> Thanks in advance.
>
> 73s
>
> Randy K6CRC
> K3#2051
> [hidden email]
>
>
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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> Post: mailto:[hidden email]
>
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>

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[Mike WA8BXN]

Randy,
 
I would suggest moving the new tuner back into your shack where you can try
doing a tune with your rig and be able to see what the tuner is actually
doing. From the manual it looks like you have to enable automatic tuning. It
could be that is not set and the tuner is just staring at you. Also, make
sure your tune power to the tuner is not greater than 10 watts.
 
73 - Mike WA8BXN
 
 
 
 
-------Original Message-------
 
From: Randy Cook
Date: 11/09/11 13:28:37
To: [hidden email]
Subject: [Elecraft] OT: Remote tuner, vertical, and K3 help needed
 
I have a weird problem that I could use help on. I have limited experience
with antennas, so the answer could be something simple I have overlooked.
 
I am using a K3/100 with the ATU. I recently installed a 31 foot vertical
antenna with ground radials and a balun at the base. The MFJ analyzer shows
an SWR (at my K3) below 1. 3:1 on 40M and near 15M as you would expect. SWR
for the other bands are much higher, about 4:1 for 17, 12, and 10. But, the
K3 tuner trims up fine. I understand the efficiency is hit, but it does work
 On 20M, the SWR is near 6:1. Again, I can tune it with the K3, but I am not
getting out well. These results are the same with the Electraft BL2 balun OR
a DX Engineering line choke installed. There is about 80 feet of LMR-400
between the rig and the antenna. I also have a static/lightning arrestor in
line.
 
In doing some research, it seems that a remote tuner at the antenna base
would be a more efficient system. I purchased a remote tuner kit from DX
Engineering, that includes an MFJ 927 tuner at the base (along with a mount
and a line choke). I bypassed the internal K3 tuner. With the remote tuner
in place, the SWR HI message is displayed on my K3 when I try to transmit
most of the time, and on all bands. The tuner was checked out by MFJ under
warranty, and came back fine. I reinstalled it, and have the same problem.
 
I verified that 12 volts is getting to the tuner. Bypassing the lightning
arrestor makes no difference. Going back to the K3 and no remote tuner works
as before.
 
Elecraft tech support was very helpful as usual. They did suggest replacing
the internal tuner with the passthrough board sold with the base K3 to see
if there was some weirdness between the two tuners. I do not have the
correct board, as I bought my rig with the tuner.
 
DX Engineering could not help me. I gave up on MFJ.
 
Does anyone have a similar configuration that is working?
 
Does anyone have the board that is in place when the ATU is not installed? I
would 'rent' it if available for testing. A new one from Elecraft is about
$60.
 
As this is a bit OT, please respond off line, and I will post any solutions
back to the reflector for future reference.
 
Thanks in advance.
 
73s
 
Randy K6CRC
K3#2051
[hidden email]
 
 
 
 
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[P.B. Christensen]

> I would suggest moving the new tuner back into your shack where you can
> try
> doing a tune with your rig and be able to see what the tuner is actually
> doing.

A few well-conducted measurements are worth a thousand expert opinions.  As
suggested by Rich, N5ZC, he should consider placement of an ATU at the base
of the vertical for the reasons cited by Owen, VK1OD:

http://vk1od.net/antenna/multibandunloadedvertical/

VK1OD first examined systematic loss of a 33 ft vertical where the ATU is at
the transmitter (e.g., within the K3).  See Fig. 1 & 2.  To increase
multiband radiation resistance, he then modeled the popular 43 vertical with
an ATU moved to the antenna's base.  See Fig. 5.  The system loss difference
is huge across the HF spectrum.

Phil, AD5X has also analyzed the 43 footer for use on 160m/80m.  His method
seems to be effective for those bands.

I'm no fan of 43 ft verticals, but absent using open line to the antenna's
base, feeding low-loss coax to an ATU located at the vertical's base is the
only way to ensure good system efficiency.  Same with a 31-33 ft vertical if
it was going to be used for multiband operation.

Paul, W9AC
 

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[Don Wilhelm-4]

Randy,

In cases like your, an antenna analyzer comes in very handy.
Do the normal "thing" to make your remote tuner tune the antenna - then
remove the coax from the K3 and attach it to the antenna analyzer.  What
is the SWR?  If it is sufficiently close to SWR=1, then you have a K3
problem, if it is not near 1, then you have an antenna/feedline/tuner
problem, and you can further break it down by measuring at different
points in the antenna system.

Don't have an antenna analyzer?  Ask if one of your local hams have one
they would be willing to lend, or they might even offer to take it to
your house and help you locate the problem.

73,
Don W3FPR



On 11/9/2011 1:28 PM, Randy Cook wrote:
> I have a weird problem that I could use help on.  I have limited experience with antennas, so the answer could be something simple I have overlooked.
>
> I am using a K3/100 with the ATU.  I recently installed a 31 foot vertical antenna with ground radials and a balun at the base. The MFJ analyzer shows an SWR (at my K3) below 1. 3:1 on 40M and near 15M as you would expect.  SWR for the other bands are much higher, about 4:1 for 17, 12, and 10. But, the K3 tuner trims up fine. I understand the efficiency is hit, but it does work. On 20M, the SWR is near 6:1. Again, I can tune it with the K3, but I am not getting out well.  These results are the same with the Electraft BL2 balun OR a DX Engineering line choke installed. There is about 80 feet of LMR-400 between the rig and the antenna.  I also have a static/lightning arrestor in line.
>
> In doing some research, it seems that a remote tuner at the antenna base would be a more efficient system. I purchased a remote tuner kit from DX Engineering, that includes an MFJ 927 tuner at the base (along with a mount and a line choke). I  bypassed the internal K3 tuner.  With the remote tuner in place, the SWR HI message is displayed on my K3 when I try to transmit most of the time, and on all bands.  The tuner was checked out by MFJ under warranty, and came back fine.  I reinstalled it, and have the same problem.
>
> I verified that 12 volts is getting to the tuner.  Bypassing the lightning arrestor makes no difference. Going back to the K3 and no remote tuner works as before.
>
>
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[David Gilbert]

Or even simply replace the antenna with the dummy load to make sure the
tuner actually works remotely.  It seems to me that some basic trouble
shooting here might possibly supplant a whole lot of conjecture.

Dave   AB7E


On 11/9/2011 12:21 PM, Ron D'Eau Claire wrote:

> Have you substituted your dummy load in place of the tuner at the antenna
> and rechecked the SWR? That will identify any connector/coax/arrester
> issues.
>
> Ron AC7AC
>
> -----Original Message-----
> I have a weird problem that I could use help on.  I have limited experience
> with antennas, so the answer could be something simple I have overlooked.
>
> I am using a K3/100 with the ATU.  I recently installed a 31 foot vertical
> antenna with ground radials and a balun at the base. The MFJ analyzer shows
> an SWR (at my K3) below 1. 3:1 on 40M and near 15M as you would expect.  SWR
> for the other bands are much higher, about 4:1 for 17, 12, and 10. But, the
> K3 tuner trims up fine. I understand the efficiency is hit, but it does
> work. On 20M, the SWR is near 6:1. Again, I can tune it with the K3, but I
> am not getting out well.  These results are the same with the Electraft BL2
> balun OR a DX Engineering line choke installed. There is about 80 feet of
> LMR-400 between the rig and the antenna.  I also have a static/lightning
> arrestor in line.
>
> In doing some research, it seems that a remote tuner at the antenna base
> would be a more efficient system. I purchased a remote tuner kit from DX
> Engineering, that includes an MFJ 927 tuner at the base (along with a mount
> and a line choke). I  bypassed the internal K3 tuner.  With the remote tuner
> in place, the SWR HI message is displayed on my K3 when I try to transmit
> most of the time, and on all bands.  The tuner was checked out by MFJ under
> warranty, and came back fine.  I reinstalled it, and have the same
> problem...
>
> Thanks in advance.
>
> 73s
>
> Randy K6CRC
> K3#2051
> [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
>

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[P.B. Christensen]

> Or even simply replace the antenna with the dummy load to make sure the
> tuner actually works remotely.  It seems to me that some basic trouble
> shooting here might possibly supplant a whole lot of conjecture.

I agree with Dave.  Disconnect the coax from the MFJ ATU.  Terminate the
line with a 50-ohm load.  Look at the input end with your MFJ analyzer and
the K3's SWR meter.  If all checks out, then reactivate the ATU and place
the 50-ohm load at the output of the MFJ ATU and invoke the autotune
function.  In both cases, SWR should read reasonably close to 1:1, and Z
measured on the MFJ analyzer (if it reads more than just SWR), should be
close to 50 ohms.  Probably stating the obvious, but also check to ensure
that the unit is really being powered by +12V to +15V and that regulation is
good (low voltage drop) during the tune sequence.

Paul, W9AC

 

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