Re: [Elecraft] KAT2 C58 & C59

[Dave Van Wallaghen]

Hi Russ,

Those light blue caps should be marked "u1J100" and if they are, those 
are 0.1uf (104) caps. They would be for C58 and C59. I use a lighted, 
magnifying lamp here. That is the only way I can read those things ;-)


73,
Dave, W8FGU


On 1/31/2020 11:01:45 AM, "kg7vq01"  wrote:


During the inventory of the kit, I found no 104 capacitors but found two small 
plastic cubes with lead and vary faint markinig i can't make out. Logic says that, 
as everyhing else is identified, these must be C58 & 59. However as logic is 
rarely relevent these days I thought I should ask. Oh, and they are blue.
Thanks for any helpRussKG7VQ


Sent from my Samsung Galaxy smartphone.
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Re: [Elecraft] KAT2 Firmware upgrade?

[Martin]

Thanks, Don.
The module is working, i hear FT-8 (sigh). Now to the alignment of the 
module.



Am 03.11.18 um 15:42 schrieb Don Wilhelm:

Martin,

No re-alignment of the KAT2 wattmeter should be necessary if it was 
already correct.


--

73, Martin

Ohne CW ist es nur CB...
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Re: [Elecraft] KAT2 Firmware upgrade?

[Don Wilhelm]

Martin,

No re-alignment of the KAT2 wattmeter should be necessary if it was 
already correct.


On the base K2, do check the voltage at the left end of R30 to make sure 
it is between 1.0 volts and 7.0 volts (1.5 to 6.5 volts is better) at 
the low frequency and high frequency ends of your preferred frequencies 
on 60 meters.  You may have to adjust L30.  If you do, then you should 
check the R30 voltages at the end points of all other bands to make sure 
they are all within range.  That is mentioned in the K60XV instructions.


You may also have to re-peak the 40 meter bandpass inductors and then 
peak the trimmer capacitors on the 60 meter board.


Other than those alignments, no other ones are necessary.

73,
Don W3FPR

On 11/3/2018 10:20 AM, Martin wrote:

Elecrafters,
i'm in the process of installing the 60m module. To make it work, i also 
need to upgrade the KAT2 firmware from 1.06 to 1.07. I just plugged the 
chip in and now wonder if i need to perform an alignment for the new 
firmware to work properly.

Anyone?


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Re: [Elecraft] KAT2 Hi Cur warning

[AE0MM via Elecraft]

Don,

Thanks for the info.


--mark/ae0mm

‐‐‐ Original Message ‐‐‐
On Saturday, September 29, 2018 12:19 PM, Don Wilhelm  
wrote:

> Mark,
>
> That is not abnormal.
>
> It is normal for the current required for one band to be a bit different
> than for other bands, and yours is not out of line. Yes, the KAT2 draws
> a bit more current than without it - that is true for any option.
>
> Move the CAL CUR setting up to 3.50 Amps.
>
> 73,
> Don W3FPR
>
> On 9/29/2018 12:19 PM, AE0MM wrote:
>
> > Don,
> > I've done the bridge null adjustment several times. The red c55 trimmer 
> > capacitor is very touchy. Using a ceramic screwdriver, I'm able to get the 
> > reading in the 7 to 10 range, but after a few moments, or hours, it will 
> > read 30 and sometimes up to 90 at 7100KHz into a dummy load on 5w requested 
> > power.
> > With requested power set to 10w, voltage drops from 13.5 to 12.9 when 
> > pressing tune. (atu set to calp)
> > It seems the biggest current change in current (before KAT2 vs after KAT2) 
> > is on 30m, 12m, and 10m. Is it normal for current to increase after 
> > installing KAT2? Are these numbers in harmony with what you'd expect? I 
> > don't have a watt meter, so I'm relying on the RF probe.
> > Here are the before and after measurements:
> > Band Power Current
> > 80 9.7 2.2
> > 40 9.2 2.0
> > 30 9.4 2.1
> > 20 9.7 2.1
> > 17 11 2.1
> > 15 9.3 2.0
> > 12 9.4 2.2
> > 10 9.6 2.3
> > 80 11.2 2.7
> > 40 10.8 2.3
> > 30 10.0 2.9
> > 20 10.8 2.5
> > 17 10.5 2.4
> > 15 10.4 2.5
> > 12 8.2 2.5
> > 10 8.5 2.9
> > What I'm experiencing, is it normal and expected?


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Re: [Elecraft] KAT2 Hi Cur warning

[Don Wilhelm]

Mark,

That is not abnormal.

It is normal for the current required for one band to be a bit different 
than for other bands, and yours is not out of line. Yes, the KAT2 draws 
a bit more current than without it - that is true for any option.


Move the CAL CUR setting up to 3.50 Amps.

73,
Don W3FPR

On 9/29/2018 12:19 PM, AE0MM wrote:

Don,

I've done the bridge null adjustment several times. The red c55 trimmer 
capacitor is very touchy. Using a ceramic screwdriver, I'm able to get the 
reading in the 7 to 10 range, but after a few moments, or hours, it will read 
30 and sometimes up to 90 at 7100KHz into a dummy load on 5w requested power.

With requested power set to 10w, voltage drops from 13.5 to 12.9 when pressing 
tune. (atu set to calp)

It seems the biggest current change in current (before KAT2 vs after KAT2) is 
on 30m, 12m, and 10m. Is it normal for current to increase after installing 
KAT2? Are these numbers in harmony with what you'd expect? I don't have a watt 
meter, so I'm relying on the RF probe.


Here are the before and after measurements:
BandPower   Current
80  9.7 2.2
40  9.2 2.0
30  9.4 2.1
20  9.7 2.1
17  11  2.1
15  9.3 2.0
12  9.4 2.2
10  9.6 2.3


80  11.22.7
40  10.82.3
30  10.02.9
20  10.82.5
17  10.52.4
15  10.42.5
12  8.2 2.5
10  8.5 2.9

What I'm experiencing, is it normal and expected?




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Re: [Elecraft] KAT2 Hi Cur warning

[AE0MM via Elecraft]

Don,

I've done the bridge null adjustment several times. The red c55 trimmer 
capacitor is very touchy. Using a ceramic screwdriver, I'm able to get the 
reading in the 7 to 10 range, but after a few moments, or hours, it will read 
30 and sometimes up to 90 at 7100KHz into a dummy load on 5w requested power.

With requested power set to 10w, voltage drops from 13.5 to 12.9 when pressing 
tune. (atu set to calp)

It seems the biggest current change in current (before KAT2 vs after KAT2) is 
on 30m, 12m, and 10m. Is it normal for current to increase after installing 
KAT2? Are these numbers in harmony with what you'd expect? I don't have a watt 
meter, so I'm relying on the RF probe.


Here are the before and after measurements:
BandPower   Current
80  9.7 2.2
40  9.2 2.0
30  9.4 2.1
20  9.7 2.1
17  11  2.1
15  9.3 2.0
12  9.4 2.2
10  9.6 2.3


80  11.22.7
40  10.82.3
30  10.02.9
20  10.82.5
17  10.52.4
15  10.42.5
12  8.2 2.5
10  8.5 2.9

What I'm experiencing, is it normal and expected?

Thanks,
--mark/ae0mm

‐‐‐ Original Message ‐‐‐
On Tuesday, September 25, 2018 5:58 PM, Don Wilhelm  
wrote:

> Mark,
>
> First, set the CAL CUR in the K2 menu to 3.50 - and also make certain
> the power supply voltage as displayed on the K2 display is not dropping
> significantly during a TUNE. If it drops more than 1 volt suspect your
> power supply or the power cable. A low supply voltage can cause the K2
> to report HI Cur - the K2 tries to maintain the power requested, and a
> lower voltage requires greater current.
>
> Note that at least 2 watts is required to calibrate the KAT2 wattmeter
> and to do a TUNE.
>
> The first step in bringing up the KAT2 is to balance (null) the
> wattmeter. Adjust the trimmer capacitor for the lowest reading in ATU
> menu CALn.
>
> After that, connect a good 50 ohm dummy load and do the CALP setting.
> Use an external wattmeter that you trust, or the measurement of the RF
> voltage with the RF Probe will work, but requires some calculation in
> between adjustments. The external wattmeter is quicker.
>
> With the ATU menu set for CALP, the relays should be set to open all
> paths to the capacitors and to short out the inductors, so I doubt that
> those relay measurements are of value - unless one of the relays has an
> unsoldered pin 1 or pin 10 which will not allow it to switch.
> Check the schematic to see which relay pins should be closed and which
> should be open.
>
> 73,
> Don W3FPR
>
> On 9/25/2018 5:35 PM, AE0MM via Elecraft wrote:
>
> > Just installed the KAT2 in a newly assembled K2. At power levels greater 
> > than 8.0 watts, the K2 was displaying the high current warning. The KAT2 
> > power calibration was calibrated by measuring voltage with the K2's RF 
> > probe at the feed point to a dummy load.
> > I removed the KAT2 and remeasured the power across all bands. Again, power 
> > was calculated based on DC voltage from RF probe at dummy load feed point. 
> > The impedance of the feedline and dummy load were retested. (49 to 51 ohms 
> > over the amateur radio bands, measured with a sark-110 calibrated using a 
> > set of reference loads)
> > Here are the results:
> > Band Power At Load K2 Current
> > 80 9.7 2.2
> > 40 9.2 2.0
> > 30 9.4 2.1
> > 20 9.7 2.1
> > 17 11 2.1
> > 15 9.3 2.0
> > 12 9.4 2.2
> > 10 9.6 2.3
> > After remeasuring power, the KAT2 was reinstalled, and its power meter 
> > verified correct at 5 watts. With the KAT2 reinstalled, rechecked K2 
> > current draw at 10 watts on all bands. For each band it measured 20% to 30% 
> > higher than without the KAT2.
> > With the power level on the K2 set to one watt and the ATU set to CALP, I 
> > used the RF probe to measure a few points on the KAT2 control board, and 
> > the input from the RF board. At the one watt level, there is approximately 
> > 1v drop between K17 pins 2/9 and 4/7.


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Re: [Elecraft] KAT2 Hi Cur warning

[Don Wilhelm]

Mark,

First, set the CAL CUR in the K2 menu to 3.50 - and also make certain 
the power supply voltage as displayed on the K2 display is not dropping 
significantly during a TUNE.  If it drops more than 1 volt suspect your 
power supply or the power cable.  A low supply voltage can cause the K2 
to report HI Cur - the K2 tries to maintain the power requested, and a 
lower voltage requires greater current.


Note that at least 2 watts is required to calibrate the KAT2 wattmeter 
and to do a TUNE.


The first step in bringing up the KAT2 is to balance (null) the 
wattmeter.  Adjust the trimmer capacitor for the lowest reading in ATU 
menu CALn.


After that, connect a good 50 ohm dummy load and do the CALP setting. 
Use an external wattmeter that you trust, or the measurement of the RF 
voltage with the RF Probe will work, but requires some calculation in 
between adjustments.  The external wattmeter is quicker.


With the ATU menu set for CALP, the relays should be set to open all 
paths to the capacitors and to short out the inductors, so I doubt that 
those relay measurements are of value - unless one of the relays has an 
unsoldered pin 1 or pin 10 which will not allow it to switch.
Check the schematic to see which relay pins should be closed and which 
should be open.


73,
Don W3FPR



On 9/25/2018 5:35 PM, AE0MM via Elecraft wrote:

Just installed the KAT2 in a newly assembled K2. At power levels greater than 
8.0 watts, the K2 was displaying the high current warning. The KAT2 power 
calibration was calibrated by measuring voltage with the K2's RF probe at the 
feed point to a dummy load.

I removed the KAT2 and remeasured the power across all bands. Again, power was 
calculated based on DC voltage from RF probe at dummy load feed point. The 
impedance of the feedline and dummy load were retested. (49 to 51 ohms over the 
amateur radio bands, measured with a sark-110 calibrated using a set of 
reference loads)

Here are the results:

BandPower At Load   K2 Current
80  9.7 2.2
40  9.2 2.0
30  9.4 2.1
20  9.7 2.1
17  11  2.1
15  9.3 2.0
12  9.4 2.2
10  9.6 2.3

After remeasuring power, the KAT2 was reinstalled, and its power meter verified 
correct at 5 watts. With the KAT2 reinstalled, rechecked K2 current draw at 10 
watts on all bands. For each band it measured 20% to 30% higher than without 
the KAT2.

With the power level on the K2 set to one watt and the ATU set to CALP, I used 
the RF probe to measure a few points on the KAT2 control board, and the input 
from the RF board. At the one watt level, there is approximately 1v drop 
between K17 pins 2/9 and 4/7.


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Re: [Elecraft] KAT2 unresponsive

[Don Wilhelm]

Bob,

The '--' in the ATU menu means that the KAT2 firmware is not being seen 
by the K2 MCU.


Take a good look at the point where the control cable is attached to the 
KAT2 control board - look for broken wires.

Do the same for the header that plugs to K2 Control Board P4.

Make certain the header which plugs into K2 Control Board P4 is 
installed correctly - the green wire should be at the top.


73,
Don W3FPR

  tuner was working fine yesterday and earlier today, and then after one

press of the "Tune" button on the front panel it is no longer functional.

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Re: [Elecraft] KAT2 Tuner issue (Ant 1 / Ant 2 switching)

[Don Wilhelm]

Tim,

When ANT2 is selected, do you hear signals if the feedline is connected 
to ANT1?  Are they at the same level as when ANT1 is selected?
If the answer is YES to both questions, then the most likely thing is 
that relay K18 is not switching.  If the signals are reduced when ANT2 
is selected, then at least K18 is disconnecting ANT1, but ANT2 is not 
connected.


If the relay is doing noting at all, it could be either the relay itself 
or the output of the firmware that is at fault.


Look for other causes before changing the relay.  I have seen burned 
leads between the BNC jack and the board (likely caused by lightning). 
Both the center conductor and the shell are connected to the board via 
leads on the back of the jack - be sure to check both.


Relays K17 and K18 are on the control board - which is the upper board 
when the top cover is turned upside down.


73,
Don W3FPR


On 12/5/2016 8:50 AM, Tim Cook wrote:

I just discovered that I have a problem with my new (to me) K2. It appears
that the antenna switch is stuck on antenna 1.  Switching between Ant 1 and
Antenna 2 with the feedline on Ant 1 doesn't change a thing in terms of
receive signals. The ANT2 indicator turns on when pressing the ANT 1/2 but
in reality it isn't switching. The tuner works fine when on antenna one.
There are no signals received when the feedline is  on Ant 2 and the
indicator for Ant 2 is illuminated.



With the tuner out of line (CALP or CALS) and switching antennas I cannot
hear the relay switch between Ant 1 and Ant 2. If I put the tuner in AUTO
and switch between Ant 1 and Ant 2 I can hear the tuner relays switch.


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Re: [Elecraft] KAT2

[Don Wilhelm]

Aaron,

The KAT2 needs only 2 watts to TUNE - in fact the firmware limits the 
power to 2 watts during a TUNE.
What was the SWR reported when you tried to tune the end-fed antenna?  
My guess is that the SWR was high.
The most common cause of LO P message is that the K2 PA cannot deliver 2 
watts - and that may mean one of 2 things - the PA transistors have been 
damaged, or the high SWR from the end-fed has damaged the diodes in the 
KAT2 wattmeter.


Do a couple tests - set the ATU menu to CALP and connect a dummy load 
(an external wattmeter between the KAT2 and dummy load is helpful).
Set the power knob to 5 watts and do a TUNE - how much power is being 
delivered.  If it significantly higher than 5 watts on the external 
wattmeter and shows little power on the K2 display, then the KAT2 diodes 
have been damaged.


After that test, you should do a test of the base K2 PA transistors.  
Remove the KAT2 (physically remove it), and use the ANT jack on the base 
K2.
Set power to 5 watts and do a TUNE.  If the power on the K2 display and 
and the external wattmeter are close to 5 watts, then the K2 PA 
transistors are OK and you will most likely find the problem in the KAT2 
wattmeter diodes.


73,
Don W3FPR


On 3/18/2016 5:56 PM, Aaron K5ATG wrote:

I recently installed the KAT2 in my K2. Using a 20 meter inverted V dipole,
it was working great with no problems. Then I tried it out on a end fed
antenna and it also tuned it up. Then I switched back to my Inverted V and
every time I try to tune it up I get LO P on the display. I looked it up
and this means Low Power, so I increased the power to 15 watts and I still
get the same message. I can't increase the power any more. Does anyone know
what is happening?



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Re: [Elecraft] KAT2 Adjustment Questions

[Don Wilhelm]

Mike,

You might try the bridge null a few times and take the average 
position.  It is quite 'touchy', and yes it may vary a bit from trial to 
trial.  As noted in the manual, the reading at the null depends on stray 
capacitance in the KAT2 - so if you moved anything it will change a bit, 
although a jump up to 30 is quite a bit.


The 3 to 4 volts depends on the exact power as well as the number of 
turns on T1.  If you have some way of monitoring the power output, you 
can see if the actual power is below 5 watts - if so, all is well.  If 
not, check T1 to see if you wound it with the correct number of turns.


73,
Don W3FPR

On 8/30/2013 5:09 PM, Michael Eberle wrote:

Hi,

I am in the process of installing the KAT2 and need some clarification 
on the bridge null adjustment procedure.  Following the instructions, 
I set the slot of C55 parallel to the K2 rear panel.  After activating 
TUNE I can adjust it down to about 002 or so.  Then if I put it back 
into receive, then activate TUNE again, it goes back up to about 030.  
Is this normal?   Also, on pin 1 of U4, I am seeing about 2.7 to 2.8 
volts.  Is this close enough to the 3 - 4 volts specified in the manual?


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Re: [Elecraft] KAT2 completion problem

[Don Wilhelm]

Tyler,

Your results are unusual.
Remove the KAT2.  Does the base K2 still work OK?  If not, something has 
happened in the meantime.


It would seem that you do not have a good path between the K2 and the 
antenna (or perhaps a short to ground).

Check the KAT2 carefully for solder bridges.

With the KAT2 in CAL P mode, you should have zero ohms resistance 
between the center conductor of the input coax and he ANT1 jack of the 
KAT2. ANT1 (with the KAT2 in CALP or CALs mode).


73,
Don W3FPR

On 7/27/2013 10:34 PM, Tyler Barnett wrote:

I've been working very slowly on a KAT2, and everything was going well and 
checking out correctly.
All the relays are working, and I finally arrived at the C55 Bridge Null 
Adjustment step.

When I put the K2 into TUNE, I got a "Hi Curr" on the panel, and no output 
power.
Not only that, but an antenna connected to port 1 of the ATU doesn't hear any 
signals.

A few steps beyond this it asks me to check pin 1 of U4 (LM358) for 0 volts 
during receive, which is OK.
During TUNE, the voltage isn't 3-4 volts, it's like 0.7 volts.
Ohand then I realized that I had already installed R6 earlier, instead of 
after the voltage check.

The shield coax of J7 is closer to the side panel of the K2 when plugged into 
J6, per the supplied addendum note.
I was very careful taking the bottom cover off, and restoring the PA screws and 
washers.
This was done to install a new J6, which was installed backwards by the 
previous owner.

The resistance between ground and the collector of both PA transistors is 87 
ohms.
The KAT2 manual says this should be higher than 100 ohms, so I don't know if 
this is substantial or not.

At this point, I'm stumped.  Comments welcome.
BTW, before I installed the KAT2, the K2 worked perfectly.




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Re: [Elecraft] KAT2 assembly

[Don Wilhelm]

Hans,

Yes, you may shorten the wire, it is the number of turns that count, not 
the wire length.
However, it is usually easier to just spread the turns out until it 
tightens up a bit.


73,
Don W3FPR

On 3/10/2013 5:27 PM, Hans Elfelt Bonnesen wrote:

On the KAT2 a number of  toroid cores are prepared and installed.
L1 and L2 are to be prepared with an extremely exact length of solid hookup 
wire.
The assembly instruction mentions that toroid cores "remain somewhat loose" 
within the winding.
That is to put it mildly. They act like a baby's rattle. Do they really have to 
be like that, or may you shorten the
length of the hook-up wire without operating deficiencies.?

Hans , OZ5RB



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Re: [Elecraft] KAT2 high SWR problem..?

[Mike K8CN]

Gil,

When you say you completed your KAT2 build, did you complete all of the
final calibration steps, specifically the bridge null adjustment (p. 16 of
the KAT2 manual) and the power calibration adjustment (p. 17)?  I would be
surprised if you could make those adjustments successfully and yet have the
low output power you indicated into a good 50 ohm dummy load - a problem
with T1 connections would be revealed during one or both of those
adjustments if that were the source of difficulty.  Be sure that you also
have selected on the K2 front panel the correct antenna port (Ant 1/2)  to
which your dummy load is attached.

73,
Mike, K8CN



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Re: [Elecraft] KAT2 C55 null

[Chuck Teague]

Operator error(s).  A relay in backwards, and a solder bridge that I cleaned
up too well, removing the trace beneath it.  Replaced the solder bridge and
all was well.

  _  

From: AF6NI [via Elecraft] [mailto:ml-node+s365791n755950...@n2.nabble.com] 
Sent: Thursday, July 19, 2012 6:28 PM
To: Chuck Teague
Subject: Re: KAT2 C55 null


Looks like the replies were directly to you so they don't show on the list.
What turned out to be the trouble? 


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Re: [Elecraft] KAT2 C55 null

[AF6NI]

Looks like the replies were directly to you so they don't show on the list.
What turned out to be the trouble? 

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Re: [Elecraft] KAT2 C55 null

[Chuck Teague]

Got it.  Thanks to  Doug, W4DAS, Gary Surrency at Elecraft and my trusty
magnifying glass everything is working well.

Chuck
NN7U 

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Re: [Elecraft] KAT2 C55 null

[Chuck Teague]

I somehow lost two emails to the ether so I can't do a direct reply, but
thanks for the response.  Yes, I'm sure it's pin 7 that has the 4.6 volts on
it.  Pin 8 has the expected 6 volts, and all the other voltages listed in
the manual check out.

NN7U

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Re: [Elecraft] KAT2 C55 nul adjustment

[Don Wilhelm]

Mike,

Yes, 1.5 is quite OK - your original email said 5:1 and that must have 
been a typo.

73,
Don W3FPR

On 4/12/2012 5:54 AM, VE3WDM wrote:
> Good morning Don, thanks very much for taking the time to respond. Good to
> know the C55 cal is in spec. As for the SWR sorry for the confusion but I am
> getting as the book says 1.1 SWR and on some bands 1.5so all is well I
> would assume?
> Mike
> VE3WDM
>
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Re: [Elecraft] KAT2 C55 nul adjustment

[VE3WDM]

Good morning Don, thanks very much for taking the time to respond. Good to
know the C55 cal is in spec. As for the SWR sorry for the confusion but I am
getting as the book says 1.1 SWR and on some bands 1.5so all is well I
would assume?
Mike
VE3WDM

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Re: [Elecraft] KAT2 C55 nul adjustment

[Don Wilhelm]

Mike,

The 009 to 010 on the balance is OK.
Under what conditions do you read an SWR of 5:1?  Is that after a TUNE 
has been completed?  Or is that reading the SWR on your antenna with the 
ATU menu set to CAL S?

What that statement in the manual is trying to say is that an SWR of 1.2 
or even 1.5 is OK.
The SWR indication does not show the ":1" part - hopefully you are not 
misreading the display - the ":1" is superfluous, it is sufficient to 
say that the SWR is 1.5 (for instance)

If it is after a TUNE, then you may have some problem with the L/C 
board, or more likely your antenna has a very high or very low impedance 
on the band in question.  The KAT2 range is large, but it it not 
infinite.  For example, it will not match the end of a half wave dipole 
which has a very high impedance.

73,
Don W3FPR

On 4/11/2012 9:13 PM, Mike Weir wrote:
> I have completed the KAT2 tuner and adjusted C55 but could only get it down 
> to between 010 - 009. I did notice that when I got a reading to 010 any 
> further adjustment would result in a large jump. I would then have to take 
> time and fine adjust C55 to 010 and maybe hit 009. I continued on with the 
> rest of the tests and adjustments and the tuner seems to work fine. The only 
> thing I did noticed was when checking out the SWR on all bands on some bands 
> I got as high as 1:5. But I did read that all bands may not read 1:1 SWR. So 
> my question is should I had been able to adjust C55 lower than between 010 
> and 009? Also is the SWR rise on some bands related to this or as it says in 
> the manual that this my happen and is just fine?MikeVE3WDM
>
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Re: [Elecraft] KAT2 only intermittently recognized by the K2

[Don Wilhelm]

Ariel,

Check the grounds.  What you are saying is that when the chassis ground 
is connected to the base K2 your KAT2 is not recognized.
Make certain the ground side of the connectors (KAT2 input coax and 
speaker wire) are on the correct side.

73,
Don W3FPR

On 12/22/2011 7:34 PM, Ariel Jacala wrote:
> Elecrafters
>
> I have been using the KPA100 for a while and the K2 QRP top has been sitting 
> quietly in its box for a few months.  Last night I decided to reconnect it 
> for potential portable use and the the K2 does not recognize its presence- 
> (i.e. the menus for the KAT2 do not show up).  I decided to unplug and 
> re-plug the connectors while the K2 top is standing next to the K2 and lo and 
> behold, the K2 recognizes it on the menu.  As soon as I bolted the top on - 
> the K2 un-recognized the KAT2.  I went through the routine of unplugging and 
> re-plugging the 12V and RF connectors but as soon as I tightened the top 
> screws the KAT2 was no longer recognized.  Has this ever happened to anyone 
> in the reflector?  Perhaps someone can shed some light to steer me to solving 
> this problem.
>
> Ariel NY4G
>   
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Re: [Elecraft] KAT2 with EFHW antenna

[Guy Olinger K2AV]

I've gotten to the point, that before I say anything about a model, I
actually run it and play with it, to make sure I haven't forgotten
something, or remembered something wrong.

As to that particular antenna a center fed half wave antenna is troublesome.
 The better version of that if one wants that pattern is the extended double
zepp, two 5/8 waves fed in phase, where you are feeding a lower impedance at
the center, and it's a far less cranky antenna. The double zepp maintains
its essential shape fed at 45% whereas the halfwave converts to cloverleaf.


That's ancient knowledge, garnered by experience in the 40's and 50's
without the benefit of software.  These days if you can't look it up for
free on the internet, it's forgotten.

73, Guy.

On Fri, Aug 26, 2011 at 12:17 PM, David Gilbert wrote:

>
> Yup ... I was wrong again, but the trouble is I can't figure out why.  I
> mean, it's easy to verify the cloverleaf pattern with EZNEC and I have done
> so, but I know that I have modeled something similar with an off-center feed
> in the past and gotten an end-fire pattern.  As soon as I figure out what
> that was I'll come back here and try to clear up the confusion I have
> caused, but in the meantime let's all just agree that I don't know what I'm
> talking about.
>
> sigh ...
>
> 73,
> Dave   AB7E
>
>
>
>
>
> On 8/25/2011 11:13 AM, Guy Olinger K2AV wrote:
>
> Sorry to interject, but a fullwave fed at the 25% point has a clover leaf
> pattern.  It only has the two halfwaves in phase colinear behavior when fed
> very near the center. Even fed at 45% it has a significant cloverleaf lobe
> and a NULL in the center  Easy to verify with any modeling program.  73,
> Guy.
>
> On Wed, Aug 24, 2011 at 8:37 PM, David Gilbert 
> wrote:
>
>>
>> Yes, Don ... you are totally correct.  For some reason I was thinking
>> about a full wave antenna fed at the 25% point (I have built such
>> antennas before), which looks like two colinear half waves fed out of
>> phase.  The current phasing along the antenna would indeed be much
>> different and give a cloverleaf pattern if it were end fed.  I
>> wholeheartedly apologize for any confusion I may have created.
>>
>> 73 and thanks for catching my mistake.
>>
>> Dave   AB7E
>>
>>
>> On 8/24/2011 3:23 PM, Don Wilhelm wrote:
>> > Actually Dave, a full wavelength wire will have a " 4 leaf clover"
>> > pattern - that is neither broadside to the antenna, nor off the ends.
>> > Check out the pattern for a 1 wavelength long wire in the ARRL Antenna
>> > Book.  The maximum radiation is about 28 degrees from the wire - the
>> > radiation from the end is almost zero.
>> >
>> > The elevation angle of maximum radiation is similar to a half wave
>> > dipole - about 15 degrees with a lesser lobe at 45 degrees (that is
>> > for a wire 70 feet high, at lower heights, the angle will be greater).
>> >
>> > 73,
>> > Don W3FPR
>> >
>> > On 8/24/2011 5:34 PM, David Gilbert wrote:
>> >>
>> >> I'm not sure I see the advantage.  A full wave end fed antenna would
>> >> theoretically have the same very high feedpoint impedance, and would
>> >> additionally blow most of it's radiated energy at a fairly high angle
>> >> off the ends of the antenna instead of broadside at a lower angle.  If
>> >> you find it that easy to tune, I suspect that electrically it really
>> >> isn't that close to a full wavelength ... possibly because of coupling
>> >> to earth (if it is low) or nearby structures.  Either that or there is
>> a
>> >> lot of loss in the system somewhere.
>> >>
>> >> 73,
>> >> Dave   AB7E
>> >>
>> >
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Re: [Elecraft] KAT2 with EFHW antenna

[David Gilbert]

Yup ... I was wrong again, but the trouble is I can't figure out why.  I 
mean, it's easy to verify the cloverleaf pattern with EZNEC and I have 
done so, but I know that I have modeled something similar with an 
off-center feed in the past and gotten an end-fire pattern.  As soon as 
I figure out what that was I'll come back here and try to clear up the 
confusion I have caused, but in the meantime let's all just agree that I 
don't know what I'm talking about.

sigh ...

73,
Dave   AB7E




On 8/25/2011 11:13 AM, Guy Olinger K2AV wrote:
> Sorry to interject, but a fullwave fed at the 25% point has a clover 
> leaf pattern.  It only has the two halfwaves in phase colinear 
> behavior when fed very near the center. Even fed at 45% it has a 
> significant cloverleaf lobe and a NULL in the center  Easy to verify 
> with any modeling program.  73, Guy.
>
> On Wed, Aug 24, 2011 at 8:37 PM, David Gilbert 
> mailto:xda...@cis-broadband.com>> wrote:
>
>
> Yes, Don ... you are totally correct.  For some reason I was thinking
> about a full wave antenna fed at the 25% point (I have built such
> antennas before), which looks like two colinear half waves fed out of
> phase.  The current phasing along the antenna would indeed be much
> different and give a cloverleaf pattern if it were end fed.  I
> wholeheartedly apologize for any confusion I may have created.
>
> 73 and thanks for catching my mistake.
>
> Dave   AB7E
>
>
> On 8/24/2011 3:23 PM, Don Wilhelm wrote:
> > Actually Dave, a full wavelength wire will have a " 4 leaf clover"
> > pattern - that is neither broadside to the antenna, nor off the
> ends.
> > Check out the pattern for a 1 wavelength long wire in the ARRL
> Antenna
> > Book.  The maximum radiation is about 28 degrees from the wire - the
> > radiation from the end is almost zero.
> >
> > The elevation angle of maximum radiation is similar to a half wave
> > dipole - about 15 degrees with a lesser lobe at 45 degrees (that is
> > for a wire 70 feet high, at lower heights, the angle will be
> greater).
> >
> > 73,
> > Don W3FPR
> >
> > On 8/24/2011 5:34 PM, David Gilbert wrote:
> >>
> >> I'm not sure I see the advantage.  A full wave end fed antenna
> would
> >> theoretically have the same very high feedpoint impedance, and
> would
> >> additionally blow most of it's radiated energy at a fairly high
> angle
> >> off the ends of the antenna instead of broadside at a lower
> angle.  If
> >> you find it that easy to tune, I suspect that electrically it
> really
> >> isn't that close to a full wavelength ... possibly because of
> coupling
> >> to earth (if it is low) or nearby structures.  Either that or
> there is a
> >> lot of loss in the system somewhere.
> >>
> >> 73,
> >> Dave   AB7E
> >>
> >
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Re: [Elecraft] KAT2 with EFHW antenna

[Guy Olinger K2AV]

Sorry to interject, but a fullwave fed at the 25% point has a clover leaf
pattern.  It only has the two halfwaves in phase colinear behavior when fed
very near the center. Even fed at 45% it has a significant cloverleaf lobe
and a NULL in the center  Easy to verify with any modeling program.  73,
Guy.

On Wed, Aug 24, 2011 at 8:37 PM, David Gilbert wrote:

>
> Yes, Don ... you are totally correct.  For some reason I was thinking
> about a full wave antenna fed at the 25% point (I have built such
> antennas before), which looks like two colinear half waves fed out of
> phase.  The current phasing along the antenna would indeed be much
> different and give a cloverleaf pattern if it were end fed.  I
> wholeheartedly apologize for any confusion I may have created.
>
> 73 and thanks for catching my mistake.
>
> Dave   AB7E
>
>
> On 8/24/2011 3:23 PM, Don Wilhelm wrote:
> > Actually Dave, a full wavelength wire will have a " 4 leaf clover"
> > pattern - that is neither broadside to the antenna, nor off the ends.
> > Check out the pattern for a 1 wavelength long wire in the ARRL Antenna
> > Book.  The maximum radiation is about 28 degrees from the wire - the
> > radiation from the end is almost zero.
> >
> > The elevation angle of maximum radiation is similar to a half wave
> > dipole - about 15 degrees with a lesser lobe at 45 degrees (that is
> > for a wire 70 feet high, at lower heights, the angle will be greater).
> >
> > 73,
> > Don W3FPR
> >
> > On 8/24/2011 5:34 PM, David Gilbert wrote:
> >>
> >> I'm not sure I see the advantage.  A full wave end fed antenna would
> >> theoretically have the same very high feedpoint impedance, and would
> >> additionally blow most of it's radiated energy at a fairly high angle
> >> off the ends of the antenna instead of broadside at a lower angle.  If
> >> you find it that easy to tune, I suspect that electrically it really
> >> isn't that close to a full wavelength ... possibly because of coupling
> >> to earth (if it is low) or nearby structures.  Either that or there is a
> >> lot of loss in the system somewhere.
> >>
> >> 73,
> >> Dave   AB7E
> >>
> >
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Re: [Elecraft] KAT2 with EFHW antenna

[David Gilbert]

Yes, Don ... you are totally correct.  For some reason I was thinking 
about a full wave antenna fed at the 25% point (I have built such 
antennas before), which looks like two colinear half waves fed out of 
phase.  The current phasing along the antenna would indeed be much 
different and give a cloverleaf pattern if it were end fed.  I 
wholeheartedly apologize for any confusion I may have created.

73 and thanks for catching my mistake.

Dave   AB7E


On 8/24/2011 3:23 PM, Don Wilhelm wrote:
> Actually Dave, a full wavelength wire will have a " 4 leaf clover" 
> pattern - that is neither broadside to the antenna, nor off the ends.  
> Check out the pattern for a 1 wavelength long wire in the ARRL Antenna 
> Book.  The maximum radiation is about 28 degrees from the wire - the 
> radiation from the end is almost zero.
>
> The elevation angle of maximum radiation is similar to a half wave 
> dipole - about 15 degrees with a lesser lobe at 45 degrees (that is 
> for a wire 70 feet high, at lower heights, the angle will be greater).
>
> 73,
> Don W3FPR
>
> On 8/24/2011 5:34 PM, David Gilbert wrote:
>>
>> I'm not sure I see the advantage.  A full wave end fed antenna would
>> theoretically have the same very high feedpoint impedance, and would
>> additionally blow most of it's radiated energy at a fairly high angle
>> off the ends of the antenna instead of broadside at a lower angle.  If
>> you find it that easy to tune, I suspect that electrically it really
>> isn't that close to a full wavelength ... possibly because of coupling
>> to earth (if it is low) or nearby structures.  Either that or there is a
>> lot of loss in the system somewhere.
>>
>> 73,
>> Dave   AB7E
>>
>
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Re: [Elecraft] KAT2 with EFHW antenna

[Ron D'Eau Claire]

I believe you must get into several wavelengths before you get significant
end directivity from a "long wire". My reference says that the angle of the
main lobe to the antenna is about 55 degrees when the wire is a wavelength
long, compared to 90 degrees at 1/2 wavelength. It takes a wire more than 7
wavelengths long for the angle of the main lobe to 20 degrees off of the
end. 

For a horizontal wire, the angle of maximum radiation with respect to the
horizon continues to be a function of height in wavelengths above ground.
So, for a given wire a specific height above ground, as the frequency goes
up, the lobes will slowly move toward the end and should be at an even
*lower* elevations in the higher frequencies since the wire is higher above
ground in terms of wavelengths. 

Of course one has to feed the wire. That's why most of us who use an end fed
wire have it arranged as an inverted "L". Mine is about 40 feet vertical
from the rig, then 90 feet horizontally. So the radiation is a strong mix of
vertical and horizontal polarization. On my favorite band, 20 meters, the
vertical section is about optimum for low-angle vertical radiation and the
height is perfect for low angle horizontal radiation. It works very well
across the HF spectrum. I use an external homebrew tuner to provide physical
separation between the very RF hot (on some bands) end of the wire and the
rig (and me at the rig).

As for impedance, it will be highest and 1/2 wavelength and diminish at
longer lengths. Cranking a sample antenna into EZNEC shows that the
impedance of a typical real-world wire at 1/4 wavelength long is about 35
ohms as expected. At 1/2 wave it's about 1500 ohms. At 1 wavelength it's
about 800 ohms. At 2 wavelength it's about 300 ohms, and so on. Of course
many things affect the actual impedance including the diameter of the
radiator itself. 

Ron AC7AC 


-Original Message-
I'm not sure I see the advantage.  A full wave end fed antenna would 
theoretically have the same very high feedpoint impedance, and would 
additionally blow most of it's radiated energy at a fairly high angle 
off the ends of the antenna instead of broadside at a lower angle.  If 
you find it that easy to tune, I suspect that electrically it really 
isn't that close to a full wavelength ... possibly because of coupling 
to earth (if it is low) or nearby structures.  Either that or there is a 
lot of loss in the system somewhere.

73,
Dave   AB7E


On 8/24/2011 2:14 PM, Niel Wiegand wrote:
> Phil,
>
> You might try a 67' length of wire (EFFW antenna). I've used that (and a
> 32' EFHW) on 20 a lot with my K1 with the KAT1 installed...tunes to
> close to 1:1 just fine.
>
> Have fun at Crater Lake. There are some neat places along the rim for
> hamming. It's a 2000 mile drive (one way) for me but I've gotten there
> twice within the past several years. See
> http://www.prismnet.com/~nielw/qrp/CraterLake_july04.jpg  and
> http://w0vlz.blogspot.com/2009/08/after-three-weeks-5300-miles-and-12.html
>
> 73,
> Niel - W0VLZ

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Re: [Elecraft] KAT2 with EFHW antenna

[Don Wilhelm]

Actually Dave, a full wavelength wire will have a " 4 leaf clover" 
pattern - that is neither broadside to the antenna, nor off the ends.  
Check out the pattern for a 1 wavelength long wire in the ARRL Antenna 
Book.  The maximum radiation is about 28 degrees from the wire - the 
radiation from the end is almost zero.

The elevation angle of maximum radiation is similar to a half wave 
dipole - about 15 degrees with a lesser lobe at 45 degrees (that is for 
a wire 70 feet high, at lower heights, the angle will be greater).

73,
Don W3FPR

On 8/24/2011 5:34 PM, David Gilbert wrote:
>
> I'm not sure I see the advantage.  A full wave end fed antenna would
> theoretically have the same very high feedpoint impedance, and would
> additionally blow most of it's radiated energy at a fairly high angle
> off the ends of the antenna instead of broadside at a lower angle.  If
> you find it that easy to tune, I suspect that electrically it really
> isn't that close to a full wavelength ... possibly because of coupling
> to earth (if it is low) or nearby structures.  Either that or there is a
> lot of loss in the system somewhere.
>
> 73,
> Dave   AB7E
>
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Re: [Elecraft] KAT2 with EFHW antenna

[David Gilbert]

I'm not sure I see the advantage.  A full wave end fed antenna would 
theoretically have the same very high feedpoint impedance, and would 
additionally blow most of it's radiated energy at a fairly high angle 
off the ends of the antenna instead of broadside at a lower angle.  If 
you find it that easy to tune, I suspect that electrically it really 
isn't that close to a full wavelength ... possibly because of coupling 
to earth (if it is low) or nearby structures.  Either that or there is a 
lot of loss in the system somewhere.

73,
Dave   AB7E





On 8/24/2011 2:14 PM, Niel Wiegand wrote:
> Phil,
>
> You might try a 67' length of wire (EFFW antenna). I've used that (and a
> 32' EFHW) on 20 a lot with my K1 with the KAT1 installed...tunes to
> close to 1:1 just fine.
>
> Have fun at Crater Lake. There are some neat places along the rim for
> hamming. It's a 2000 mile drive (one way) for me but I've gotten there
> twice within the past several years. See
> http://www.prismnet.com/~nielw/qrp/CraterLake_july04.jpg  and
> http://w0vlz.blogspot.com/2009/08/after-three-weeks-5300-miles-and-12.html
>
> 73,
> Niel - W0VLZ
>
>
>
>> Message: 2
>> Date: Tue, 23 Aug 2011 16:00:17 -0700
>> From: "Phillip Shepard"
>> Subject: [Elecraft] KAT2 with EFHW antenna
>> To:
>> Message-ID:
>> Content-Type: text/plain;charset="us-ascii"
>>
>> I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
>> for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
>> two 16' counterpoise wires.  It seems to work well for what it is and 10W.
>> I just built and installed the KAT2 ATU into the K2 to lighten my pack by
>> the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
>> had a very hard time getting a good match to the antenna.  In AUTO mode, it
>> only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
>> long time searching before it got down to between 3:1 and 4:1, depending on
>> the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
>> got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'), and
>> it got down to about 1.5:1.  Five or six feet added yielded a perfect match
>> (1:1).  So I now have a 39' wire for 20m use.
>>
>> Is this normal?  Should the KAT2 be able to more easily match the 33'
>> halfwave antenna?  Thank you.
>>
>> 73,
>> Phl, NS7P
>>
>>
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Re: [Elecraft] KAT2 with EFHW antenna

[Niel Wiegand]

Phil,

You might try a 67' length of wire (EFFW antenna). I've used that (and a 
32' EFHW) on 20 a lot with my K1 with the KAT1 installed...tunes to 
close to 1:1 just fine.

Have fun at Crater Lake. There are some neat places along the rim for 
hamming. It's a 2000 mile drive (one way) for me but I've gotten there 
twice within the past several years. See 
http://www.prismnet.com/~nielw/qrp/CraterLake_july04.jpg  and 
http://w0vlz.blogspot.com/2009/08/after-three-weeks-5300-miles-and-12.html

73,
Niel - W0VLZ



> Message: 2
> Date: Tue, 23 Aug 2011 16:00:17 -0700
> From: "Phillip Shepard"
> Subject: [Elecraft] KAT2 with EFHW antenna
> To:
> Message-ID:
> Content-Type: text/plain; charset="us-ascii"
>
> I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
> for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
> two 16' counterpoise wires.  It seems to work well for what it is and 10W.
> I just built and installed the KAT2 ATU into the K2 to lighten my pack by
> the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
> had a very hard time getting a good match to the antenna.  In AUTO mode, it
> only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
> long time searching before it got down to between 3:1 and 4:1, depending on
> the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
> got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'), and
> it got down to about 1.5:1.  Five or six feet added yielded a perfect match
> (1:1).  So I now have a 39' wire for 20m use.
>
> Is this normal?  Should the KAT2 be able to more easily match the 33'
> halfwave antenna?  Thank you.
>
> 73,
> Phl, NS7P
>
>


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Re: [Elecraft] KAT2 with EFHW antenna

[Vic K2VCO]

Just speculating -- I bet a half-wavelength wire in inverted-L configuration 
fed at the 
base with a parallel-tuned circuit would work well. The high-current part of 
the vertical 
piece would be at the top, there would be plenty of current in the horizontal 
part too, 
and very little local ground current.

On 8/24/2011 6:54 AM, William Ravenel wrote:
> Steve Yates, AA5TB, has a very informative web page on EFHW antennas and how 
> to build a
> parallel tuned circuit with a link coupled feed at the radio end to reduce 
> the 1800 to
> 5000 ohm impedance to a 50 ohm non-reactive load. He has examples of both QRP 
> and QRO
> versions of the circuit. I built the QRP version which uses a polyvaricon 
> capacitor
> (available through Hendrix Kits among other sources) to create a very small 
> tuning
> device that will match resonant End Fed half wavelength antennas on 40m, 30m, 
> 20m, and
> 17m. I use it mostly with a 33 foot wire on 20m raised on a 31 foot Jackite 
> fiberglass
> pole and have had fun working DX with 5 watts. It is easy to change bands by 
> exchanging
> the wire with one cut for the band of interest. I do not use a counterpoise 
> and do not
> have any trouble at the rig. Steve explains why this works. For higher power 
> a one
> meter counterpoise helps. I use this antenna with a K1 and K2, both with 
> internal
> antenna tuners. The tuners are not needed, but I leave them activated to 
> easily
> compensate for any small mismatch across the band.
>
> Steve's page is found at http://aa5tb.com/efha.html
>
> William Ravenel, AI4VE 
> __

-- 
Vic, K2VCO
Fresno CA
http://www.qsl.net/k2vco/
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Re: [Elecraft] KAT2 with EFHW antenna

[Ron D'Eau Claire]

33 feet is a 1/2 wave on 20 meters all right. I was using the figures given in 
the homebrew article that suggested a much shorter wire.  

Yes, Wayne came up with the 28' radiator with 33'counerpoise as a combination 
that the little ATU in the KX1 could handle on all the bands it covers. The KX1 
ATU has a more limited matching range than most of the tuners, including the 
other tuners in Elecraft rigs, because there simply wasn't room for more 
inductor/capacitor combinations in very limited space available. 

73, 

Ron AC7AC



-Original Message-

Ron, the one I purchased for $42 is for 20 meters and came with a 33 
foot radiator.  A mathematical half wave at 14 MHz would work out to 
32.8 feet.  It did not come with a counterpoise nor was one recommended. 
It loaded up nicely for me as received.  I later tried a short 
counterpoise and did not note any difference in performance.   I use a 
short coax of about 12 feet for portable work.  It seems to work very 
well and only having to worry about hanging one end is convenient.  And 
the wire is a nice quality that resists tangling.

The documentation that came with mine warned that for 40 meter use, I'd 
need to replace the radiator with a 66 foot length and a wing nut 
arrangement is provided for that.  I've never tried it on 40 meters.

Ron, I'm no antenna expert (hence "more money than brains") but I'd like 
to add that the precursor to this EFWHA came right out of the KX1 
documentation.  It's just a double BNC connector with a 28' radiator and 
a 33' counterpoise.  I moved to the EFHWA because I got tired of 
untangling the two wires.

In a side by side test, both antennas sounded the same to my ear.  I 
retired the double BNC affair in favor of the EFWHA because I figured 
the EFWHA was a more efficient radiator, as you pointed out.  Something 
my ears wouldn't necessarily disclose to me.

I apologize for not having re-read the material on those links I 
provided.  Apparently something has changed since I purchased mine.

73, Stan WB2LQF


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Re: [Elecraft] KAT2 with EFHW antenna

[stan levandowski]

Ron, the one I purchased for $42 is for 20 meters and came with a 33 
foot radiator.  A mathematical half wave at 14 MHz would work out to 
32.8 feet.  It did not come with a counterpoise nor was one recommended. 
It loaded up nicely for me as received.  I later tried a short 
counterpoise and did not note any difference in performance.   I use a 
short coax of about 12 feet for portable work.  It seems to work very 
well and only having to worry about hanging one end is convenient.  And 
the wire is a nice quality that resists tangling.

The documentation that came with mine warned that for 40 meter use, I'd 
need to replace the radiator with a 66 foot length and a wing nut 
arrangement is provided for that.  I've never tried it on 40 meters.

Ron, I'm no antenna expert (hence "more money than brains") but I'd like 
to add that the precursor to this EFWHA came right out of the KX1 
documentation.  It's just a double BNC connector with a 28' radiator and 
a 33' counterpoise.  I moved to the EFHWA because I got tired of 
untangling the two wires.

In a side by side test, both antennas sounded the same to my ear.  I 
retired the double BNC affair in favor of the EFWHA because I figured 
the EFWHA was a more efficient radiator, as you pointed out.  Something 
my ears wouldn't necessarily disclose to me.

I apologize for not having re-read the material on those links I 
provided.  Apparently something has changed since I purchased mine.

73, Stan WB2LQF


On Wed, Aug 24, 2011 at 11:06 AM, Ron D'Eau Claire wrote:

> Stan, that's not a true half wave radiator on most bands. They suggest 
> a
> wire length of 20 or 30 feet, which will be efficient on 12 through 6 
> meters
> where it's at least 1/2 wavelength long, but on the lower frequency 
> bands
> it's just a short random length wire with an auto-transformer to 
> assist with
> impedance matching.
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Re: [Elecraft] KAT2 with EFHW antenna

[Ron D'Eau Claire]

Stan, that's not a true half wave radiator on most bands. They suggest a
wire length of 20 or 30 feet, which will be efficient on 12 through 6 meters
where it's at least 1/2 wavelength long, but on the lower frequency bands
it's just a short random length wire with an auto-transformer to assist with
impedance matching. 

There's a huge difference between a full-size radiator and a short one that
is made "resonant" using supplemental inductance. It will work as you, I, or
anyone who has used a short, random length wire can attest, but it's
efficiency is much lower than a radiator that is physically a half
wavelength long. 

There's just nothing that can replace physical size for an efficient
antenna. Not too much is lost on even multiples of a half wavelength. The
impedance at a full wavelength, two wavelengths, etc., drops with each
multiple, but still remains far above that impedance of even a 1/4 wave
length radiator. And when dealing with any end-fed antenna worked against
ground, higher impedance at the end of the antenna means higher efficiency
for a given ground. 

73,

Ron AC7AC


-Original Message-

And for those with more money than brains (that would be me) you can 
purchase an end fed halfwave antenna from the Emergency Radio Club of 
Hawaii for $42.  I bought one and it works great with the entire 
Elecraft family. Great to have a simple yet efficient portable antenna 
that fits into a sandwich baggie.   This site also has the plans to 
build this one on your own if you would prefer.

The main website is at:  http://www.earchi.org/proj_homebrew.html

The page for building it yourself is at: 
http://www.earchi.org/pdf/endfed.pdf

And the page for the 'easy way out' is at: 
http://www.earchi.org/pdf/endfed20.pdf


73, Stan WB2LQF
KX1 #2411K1#2994K2# 6980K3#5244 K9 #1 (Cocoa the 
Chihuahua)
Everything is QRP, even the dog.


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Re: [Elecraft] KAT2 with EFHW antenna

[stan levandowski]

And for those with more money than brains (that would be me) you can 
purchase an end fed halfwave antenna from the Emergency Radio Club of 
Hawaii for $42.  I bought one and it works great with the entire 
Elecraft family. Great to have a simple yet efficient portable antenna 
that fits into a sandwich baggie.   This site also has the plans to 
build this one on your own if you would prefer.

The main website is at:  http://www.earchi.org/proj_homebrew.html

The page for building it yourself is at: 
http://www.earchi.org/pdf/endfed.pdf

And the page for the 'easy way out' is at: 
http://www.earchi.org/pdf/endfed20.pdf


73, Stan WB2LQF
KX1 #2411K1#2994K2# 6980K3#5244 K9 #1 (Cocoa the 
Chihuahua)
Everything is QRP, even the dog.





On Wed, Aug 24, 2011 at 9:54 AM, William Ravenel wrote:

> Steve Yates, AA5TB, has a very informative web page on EFHW antennas 
> and how to build a parallel tuned circuit with a link coupled feed at 
> the radio end to reduce the 1800 to 5000 ohm impedance to a 50 ohm 
> non-reactive load. He has examples of both QRP and QRO versions of the 
> circuit. I built the QRP version which uses a polyvaricon capacitor 
> (available through Hendrix Kits among other sources) to create a very 
> small tuning device that will match resonant End Fed half wavelength 
> antennas on 40m, 30m, 20m, and 17m. I use it mostly with a 33 foot 
> wire on 20m raised on a 31 foot Jackite fiberglass pole and have had 
> fun working DX with 5 watts. It is easy to change bands by exchanging 
> the wire with one cut for the band of interest. I do not use a 
> counterpoise and do not have any trouble at the rig. Steve explains 
> why this works. For higher power a one meter counterpoise helps. I use 
> this antenna with a K1 and K2, both with internal antenna tuners. The 
> tuners are not needed, but I
>   leave them activated to easily compensate for any small mismatch 
> across the band.
>
> Steve's page is found at http://aa5tb.com/efha.html
>
> William Ravenel, AI4VE
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Re: [Elecraft] KAT2 with EFHW antenna

[William Ravenel]

Steve Yates, AA5TB, has a very informative web page on EFHW antennas and how to 
build a parallel tuned circuit with a link coupled feed at the radio end to 
reduce the 1800 to 5000 ohm impedance to a 50 ohm non-reactive load. He has 
examples of both QRP and QRO versions of the circuit. I built the QRP version 
which uses a polyvaricon capacitor (available through Hendrix Kits among other 
sources) to create a very small tuning device that will match resonant End Fed 
half wavelength antennas on 40m, 30m, 20m, and 17m. I use it mostly with a 33 
foot wire on 20m raised on a 31 foot Jackite fiberglass pole and have had fun 
working DX with 5 watts. It is easy to change bands by exchanging the wire with 
one cut for the band of interest. I do not use a counterpoise and do not have 
any trouble at the rig. Steve explains why this works. For higher power a one 
meter counterpoise helps. I use this antenna with a K1 and K2, both with 
internal antenna tuners. The tuners are not needed, but I
  leave them activated to easily compensate for any small mismatch across the 
band.

Steve's page is found at http://aa5tb.com/efha.html

William Ravenel, AI4VE
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Re: [Elecraft] KAT2 with EFHW antenna

[Bob Willis]

Another simple end fed antenna was described by W2FRH in QST, March 2011, "A 
Near End-Fed Antenna..." .  I just returned from a week at the Outer Banks and 
used this antenna with my K2 working DX from Europe and South America, plus 
several states.  No trees near the beach house so it was a sloper from the top 
deck to a fence post.  Measured SWR around 2:1 and the K2 matched to 1:1.

73 Bob K2GLS

I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
two 16' counterpoise wires.  It seems to work well for what it is and 10W.
I just built and installed the KAT2 ATU into the K2 to lighten my pack by
the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
had a very hard time getting a good match to the antenna.  In AUTO mode, it
only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
long time searching before it got down to between 3:1 and 4:1, depending on
the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'),
and
it got down to about 1.5:1.  Five or six feet added yielded a perfect match
(1:1).  So I now have a 39' wire for 20m use.

Is this normal?  Should the KAT2 be able to more easily match the 33'
halfwave antenna?  Thank you.

73,
Phl, NS7P

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Re: [Elecraft] KAT2 with EFHW antenna

[Guy Olinger K2AV]

An EFHW is a very efficient antenna, but the usual tuner needs help.  One
way to use the EFHW is to put a toroidal winding at the base of the antenna,
between the tuner and the antenna. Bifilar or trifilar or quadrifilar
windings configured as a tapped winding will reduce the tough impedance to
something that the tuner will handle easily.

The 80 meter version of this, an end-fed half-wave L fed against ground is
probably the best single wire antenna for 80 meters that there is.

73, Guy.

On Tue, Aug 23, 2011 at 11:50 PM, Phillip Shepard  wrote:

> Thanks for all of the great advice.  This reflector is a fountain of
> knowledge!  I checked the 33' antenna/16' counterpoise combination with an
> MFJ259B, and it indicated over 25:1 SWR.  Extending the antenna to 39' and
> adding a second "radial" of 6' gave an SWR reading of about 11:1 with the
> antenna analyzer.  The KAT2 seems to handle that much better.  This will
> get
> me through one or two SOTA peaks at Crater Lake later this week; and I can
> look for better solutions after that.  Thanks again.
>
> 73,
>
> Phil, NS7P
>
> -Original Message-
> From: elecraft-boun...@mailman.qth.net
> [mailto:elecraft-boun...@mailman.qth.net]On Behalf Of Phillip Shepard
> Sent: Tuesday, August 23, 2011 4:00 PM
> To: elecraft@mailman.qth.net
> Subject: [Elecraft] KAT2 with EFHW antenna
>
>
> I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
> for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
> two 16' counterpoise wires.  It seems to work well for what it is and 10W.
> I just built and installed the KAT2 ATU into the K2 to lighten my pack by
> the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
> had a very hard time getting a good match to the antenna.  In AUTO mode, it
> only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
> long time searching before it got down to between 3:1 and 4:1, depending on
> the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
> got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'),
> and
> it got down to about 1.5:1.  Five or six feet added yielded a perfect match
> (1:1).  So I now have a 39' wire for 20m use.
>
> Is this normal?  Should the KAT2 be able to more easily match the 33'
> halfwave antenna?  Thank you.
>
> 73,
> Phl, NS7P
>
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Re: [Elecraft] KAT2 with EFHW antenna

[Phillip Shepard]

Thanks for all of the great advice.  This reflector is a fountain of
knowledge!  I checked the 33' antenna/16' counterpoise combination with an
MFJ259B, and it indicated over 25:1 SWR.  Extending the antenna to 39' and
adding a second "radial" of 6' gave an SWR reading of about 11:1 with the
antenna analyzer.  The KAT2 seems to handle that much better.  This will get
me through one or two SOTA peaks at Crater Lake later this week; and I can
look for better solutions after that.  Thanks again.

73,

Phil, NS7P

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net]On Behalf Of Phillip Shepard
Sent: Tuesday, August 23, 2011 4:00 PM
To: elecraft@mailman.qth.net
Subject: [Elecraft] KAT2 with EFHW antenna


I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
two 16' counterpoise wires.  It seems to work well for what it is and 10W.
I just built and installed the KAT2 ATU into the K2 to lighten my pack by
the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
had a very hard time getting a good match to the antenna.  In AUTO mode, it
only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
long time searching before it got down to between 3:1 and 4:1, depending on
the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'), and
it got down to about 1.5:1.  Five or six feet added yielded a perfect match
(1:1).  So I now have a 39' wire for 20m use.

Is this normal?  Should the KAT2 be able to more easily match the 33'
halfwave antenna?  Thank you.

73,
Phl, NS7P

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Re: [Elecraft] KAT2 with EFHW antenna

[Don Wilhelm]

Phil,

As others have responded, attempting to tune the end of a half-wave wire 
is beyond the range of most tuners, including the KAT2.
Your added wire provided a compromise length, because the feedpoint 
impedance was reduced.

Because the impedance of the EFHW is high, my favorite tuning section 
for a half wave antenna is a parallel tuned tank circuit - the radiator 
connects to one side of the parallel circuit  and your counterpoise (or 
ground) connects to the "cold end".  Tune the paralled tank circuit for 
resonance near the operating frequency (and make it a permanent part of 
the antenna).  Then wrap a few turns around the ground end of the 
inductor and use that "link" to connect to the KAT2.  The fixed tuned 
circuit will handle the high impedance, and the impedance of the "link" 
will be much lower (depends on the square of the turns ratio).  The KAT2 
will do the job of matching into that link as you move about the band.

In other words, you make a fixed "tuner" that becomes part of your EFHW 
dipole (no variable capacitor to tune the antenna - use a fixed 
capacitor that resonates with the inductor approximately mid-band.  The 
KAT2 will tune quite nicely into the link winding and produce a low SWR.

The alternative is to use a non-resonant wire length that provides a 
sufficiently low impedance as to be within the matching range of the 
tuner.  The W3EDP antenna is one of those examples.  Use that approach 
if you want to use the same antenna wire for multiple bands.  As I 
recall, the W3EDP radiator is 85 feet long and the "counterpoise" is 17 
feet for use on 80 meters and up.  Half those lengths would work on 40 
and up.  I look at the W3EDP as "sort-of" an off-center-fed" dipole - 
the counterpoise does not have to be on the ground to work well.

73,
Don W3FPR

On 8/23/2011 7:00 PM, Phillip Shepard wrote:
> I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
> for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
> two 16' counterpoise wires.  It seems to work well for what it is and 10W.
> I just built and installed the KAT2 ATU into the K2 to lighten my pack by
> the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
> had a very hard time getting a good match to the antenna.  In AUTO mode, it
> only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
> long time searching before it got down to between 3:1 and 4:1, depending on
> the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
> got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'), and
> it got down to about 1.5:1.  Five or six feet added yielded a perfect match
> (1:1).  So I now have a 39' wire for 20m use.
>
> Is this normal?  Should the KAT2 be able to more easily match the 33'
> halfwave antenna?  Thank you.
>
> 73,
> Phl, NS7P
>
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Re: [Elecraft] KAT2 with EFHW antenna

[Ron D'Eau Claire]

But, on the positive side, that very high impedance means an unusually
efficient antenna since there is almost no ground current flowing at all. 

I use a setup like that at my home station - 1/2 wavelength long wire on 80
meters - with a homebrew manual L-network. Does a great job. 

One reason why small auto-tuners cannot handle that huge impedance is
because of the voltages involved. Thousands of volts commonly exist even
with fairly low power. The capacitors and inductors in most automatic tuners
simply aren't rated for that.

Ron AC7AC 

-Original Message-
From: elecraft-boun...@mailman.qth.net
[mailto:elecraft-boun...@mailman.qth.net] On Behalf Of David Gilbert
Sent: Tuesday, August 23, 2011 4:20 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] KAT2 with EFHW antenna


The simple answer to your question is "no".  An end fed halfwave would 
theoretically present a few thousand ohms to your feedline, giving you 
an SWR of several tens to one.

Consider this  it is likely that the tuner with the greater loss 
will more easily give you a "match" to a difficult load.

73,
Dave   AB7E


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Re: [Elecraft] KAT2 with EFHW antenna

[David Gilbert]

The simple answer to your question is "no".  An end fed halfwave would 
theoretically present a few thousand ohms to your feedline, giving you 
an SWR of several tens to one.

Consider this  it is likely that the tuner with the greater loss 
will more easily give you a "match" to a difficult load.

73,
Dave   AB7E



On 8/23/2011 4:00 PM, Phillip Shepard wrote:
> I have been using my K2 with an MFJ tuner to feed an end fed halfwave wire
> for portable use (like SOTA).  The 20m antenna is 33' long and I use one or
> two 16' counterpoise wires.  It seems to work well for what it is and 10W.
> I just built and installed the KAT2 ATU into the K2 to lighten my pack by
> the loss of the MFJ.  The KAT2 tuner checked out fine on the bench, but it
> had a very hard time getting a good match to the antenna.  In AUTO mode, it
> only got the SWR down to about 5:1.  I put it in ALT mode, and it spent a
> long time searching before it got down to between 3:1 and 4:1, depending on
> the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
> got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'), and
> it got down to about 1.5:1.  Five or six feet added yielded a perfect match
> (1:1).  So I now have a 39' wire for 20m use.
>
> Is this normal?  Should the KAT2 be able to more easily match the 33'
> halfwave antenna?  Thank you.
>
> 73,
> Phl, NS7P
>
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Re: [Elecraft] KAT2 with EFHW antenna

[Bill W4ZV]

Phillip Shepard wrote:
> I put it in ALT mode, and it spent a
> long time searching before it got down to between 3:1 and 4:1, depending
> on
> the 20m frequency.  I added about 2" of wire to the antenna, and the tuer
> got down to about 2:1 to 2.5:1.  I added another foot of wire (now 36'),
> and
> it got down to about 1.5:1.  Five or six feet added yielded a perfect
> match
> (1:1).  So I now have a 39' wire for 20m use.
> 
> Is this normal?  Should the KAT2 be able to more easily match the 33'
> halfwave antenna?  Thank you.
> 

Probably normal.  End-fed half-wave antennas are 4-5000 ohms impedance, so
you're asking the tuner to match an 80-100:1 SWR which is beyond the range
of most tuners.

73,  Bill


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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Sorry Don,

I was using the DMM leads and not the RF probe to read the voltage on the
DL1 measuring 6 volts.

Thanks again Don,

Ed

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Re: [Elecraft] KAT2 Bridge null adjustment

[Don Wilhelm]

Ed,

Not enough information, so I am forced to make assumptions.
Are you using the RF probe to measure the RF voltage across the dummy 
load?  If so, 6 volts yields 0.72 watts as you stated, but if you have 
the Elecraft DL1 and measure 6 volts, the power is 1.49 watts.

Adjust R1 to agree with the external power reading.

If you continue to see extreme fluctuation in the power displayed by the 
K2, you may want to change the value of R98 on the bottom of the RF 
board.  See http://www.elecraft.com/Apps/Power_Control_Mod.html for the 
"rest of the story".

73,
Don W3FPR

On 8/13/2011 9:30 PM, EMD wrote:
> Don,
>
> When I use the DMM and measure the Voltage across I am only getting 6.0
> volts.  When I plug that into P=V*V/R I get .72volts.  I have also noticed
> that when I push TUNE I sometime see a fluctuating power indication and
> other times I see 2.4f 0.0r.  So what should I be looking at to adjust R1.
> Sorry to be so dense but this has me confused.  Also when I select TUNE the
> S meter fluctuates with the power display.
>
> 73,
> Ed ke7hga
>
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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Don,

When I use the DMM and measure the Voltage across I am only getting 6.0
volts.  When I plug that into P=V*V/R I get .72volts.  I have also noticed
that when I push TUNE I sometime see a fluctuating power indication and
other times I see 2.4f 0.0r.  So what should I be looking at to adjust R1. 
Sorry to be so dense but this has me confused.  Also when I select TUNE the
S meter fluctuates with the power display.

73,
Ed ke7hga 

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Re: [Elecraft] KAT2 Bridge null adjustment

[Don Wilhelm]

Ed,

I would also recommend doing the power calibration on 40 meters - it is 
a good compromise.  There \is some variation in the response of the 
diodes with respect to frequency, and also, if you are using an 
oscilloscope to measure the RF voltage, the bandwidth of the 'scope can 
cause some "confusion" - if your 'scope (and probe) is rated at 35 MHz, 
the vertical response will be down  3 dB at 35 MHz.  The use of a 'scope 
rated at 35 MHz can be used for RF voltage measurements at 7 MHz, but 
using it at 14 MHz, expect that the RF voltage shown by the scope will 
be less than the actual RF voltage.  Do not even think of using a hunk 
of coax attached to the 'scope to measure RF voltages with any accuracy 
- a 10X probe is mandatory to keep the 'scope from loading the device to 
be measured (in this case, the transmitter output).

73,
Don W3FPR

On 8/13/2011 7:53 PM, EMD wrote:
> Thanks Don,
>
> I will give that a try.  Should I use the RF probe that I made or just use
> the DMM probes?
>
> 73,
> Ed ke7hga
>
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Re: [Elecraft] KAT2 Bridge null adjustment

[Don Wilhelm]

Ed,

With the Elecraft DL1, just use the DMM probes.
If you do not have the DL1, connect the RF Probe across the dummy load 
(use a Tee adapter if you do not have direct access to the dummy load 
terminals) - but keep the power to 5 watts or less to keep from zapping 
the diode in the RF probe.

You can also use an oscilloscope (with a 10X probe) to measure the peak 
to peak RF voltage across the dummy load.  In that case, the calculation 
formula is Power = (Vp-p) squared and divided by 400.  Derivation left 
to the student.

73,
Don W3FPR

On 8/13/2011 7:53 PM, EMD wrote:
> Thanks Don,
>
> I will give that a try.  Should I use the RF probe that I made or just use
> the DMM probes?
>
> 73,
> Ed ke7hga
>
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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Thanks Don,

I will give that a try.  Should I use the RF probe that I made or just use
the DMM probes?

73,
Ed ke7hga

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Re: [Elecraft] KAT2 Bridge null adjustment

[Don Wilhelm]

Ed,

Do I recall that you have the Elecraft DL1?  If so, you have the perfect 
item for calibrating the power - in fact, better than most wattmeters.  
Just measure the DC voltage at the diode and calculate the power - set 
the forward voltage pot so the K2 indicates that same power, and job done.

73,
Don W3FPR

On 8/13/2011 7:01 PM, EMD wrote:
> Okay Don thanks again.  I did not indicate any voltage during receive. I
> think I'm going to wait until I get some sort of watt meter before I
> continue.  But I'm off to work so that will have to wait until next month.
>
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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Okay Don thanks again.  I did not indicate any voltage during receive. I
think I'm going to wait until I get some sort of watt meter before I
continue.  But I'm off to work so that will have to wait until next month.

73,
Ed ke7hga


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Re: [Elecraft] KAT2 Bridge null adjustment

[Don Wilhelm]

Ed,

No, R6 will not influence the bridge null.  You are instructed to leave 
it out until you check the voltage at U4 pin 1, during receive - it 
should be zero - but you can also check that with R6 in.  The zero 
voltage in receive is the important one to the rest of the K2.  If you 
do detect voltage during receive, then remove R6 until you can find the 
problem, otherwise leave it in.
The check for voltage in transmit is to be sure things are working right 
in the wattmeter output, but that can also be checked with R6 installed.

73,
Don W3FPR

On 8/13/2011 5:06 PM, EMD wrote:
> Don,
>
> I just realized that I had done the Bridge null adjustment with R6
> installed.  So should I remove it and start over?
>
> 73,
> Ed ke7hga
>
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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Don, 

I just realized that I had done the Bridge null adjustment with R6
installed.  So should I remove it and start over? 

73,
Ed ke7hga

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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Don

I was using a cable to connect my Dummy load to the tuner.  So I decided to
see if maybe the connection could be bad so I connected the tuner directly
to the #1 antenna jack and that was it.  Now I have a steady power ready of
3.0 volts.

Thanks again.

73,
Ed ke7hga

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Re: [Elecraft] KAT2 Bridge null adjustment

[EMD]

Thanks Don I will start looking into those areas.

73,
Ed ke7hga

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Re: [Elecraft] KAT2 Bridge null adjustment

[Don Wilhelm]

Ed,

The most common cause is T1 connected incorrectly or having 
insufficiently stripped and tinned leads, so check that first.
The HiCur message may indicate a bad or incorrectly oriented diode.
Check all the components in the wattmeter area for good soldering and 
correct values T1, D1, D2, C54, C55, R3, R4, C50, C51, R1, R2, C52, and C53.

Check for continuity from the center conductor of the input cable to the 
center of the selected BNC antenna jack - you should find a very low 
resistance (quite close to zero).  Also check for a short from the 
center conductor to ground.

A relay that is not operating properly (due to an unsoldered pin) can 
also cause that behavior.

If that does not correct things, I can tell you how to bypass the L-C 
board and test the wattmeter section alone.

73,
Don W3FPR

On 8/13/2011 2:03 PM, EMD wrote:
> Hello,
>
> When I adjust C55 I initially get a high current message that last for a
> second, followed by a fluctuating power indication.  The lowest I can adjust
> c55 down to is 1.7 volts.
>
> So what have I missed.  Thanks in advance.
>
> 73,
> Ed ke7hga
>
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Re: [Elecraft] KAT2 J8

[EMD]

Don,

I understand now, thanks.

Ed

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Re: [Elecraft] KAT2 J8

[Don Wilhelm]

The instructions tell you to insert all of the pins so the connector 
will be more difficult to remove (so it will not fall off by itself).  I 
do not consider that a problem, if you put in only the 4 pins which have 
wires attached, the force required to insert the connector (and remove 
it) is considerable.  In other words, I do not think it will fall off 
with only those 4 pins inserted.  But make your choice - only the 4 pins 
or insert all the unused pins.  Electrically, it makes no difference, 
mechanically, it will take more force to insert and remove the connector 
if all the pins are inserted.

73,
Don
W3FPR

On 8/8/2011 10:37 PM, EMD wrote:
> Hello,
>
> I'm confused on the construction of J8.  First the manual states there are
> 12 mini crimp pins including 2 spares.  J8 has ten pins but I only have 4
> wires that come the Control board minus the bare lead.  So am I inserting
> the crimp pins with the wires in one side of J8 and inserting empty ones on
> the opposite side?
>
> Or maybe this will make sense in the morning.  Thanks in advance.
>
>
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Re: [Elecraft] KAT2 Build Question

[Don Wilhelm]

David,

Just follow the instructions in order and all will be well.  You must 
flush cut the relay leads after soldering, and that will not be easy if 
you mount the capacitors first.

When it comes to the capacitors that fit above the relays, yes, you will 
trim the leads before soldering as instructed in the manual.  The 
inductor leads are similar - just follow the instructions.

73,
Don W3FPR

On 7/28/2011 9:24 AM, David Dietrich wrote:
> Hi All,
>
> I consider myself to be a pretty experienced kit builder. Normally I follow 
> the instructions step-by-step, but sometimes I deviate if it will make things 
> go smoother for me.
>
> I am working on the KAT2 right now. I am starting the L-C board. The manual 
> says to install all the relays after I installed those small "102" caps. I 
> noticed that other caps go into holes that will be directly under the relays 
> on the other side of the board. My dilemma is that I am concerned that if I 
> don't install those caps BEFORE installing the relays, I run the risk of 
> piercing them with the leads or having solder go through and melt them. I 
> know how fragile the relays are because I nicked one with my soldering iron 
> when I built my K1. It had to be replaced. Conversely, if I install the caps 
> first, I run the risk of not having the relays sit flat...even if I trim the 
> leads beforehand. I know this is a critical issue as space is at a premium on 
> the boards, and it has to fit with it's control board within tight 
> tolerances. Should I follow the instructions, or deviate slightly so I know I 
> won't damage something? The KAT2 is quite possibly the most important option 
> one wou
 ld
>buy.
>
> 73 es thanks,
>
> David
> KC9EHQ
> K1-4 s/n 2051
> K2 s/n 7164
>
> Sent from my iPod
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Re: [Elecraft] KAT2

[Don Wilhelm]

  Peter,

I forget what the E000 error really means, but those kind of errors come 
from the option firmware.
If you have a 'scope with a 10x probe, you can check for oscillation at 
the resonator pins (or U1 pins 13 and 14).
Check your cable connections and your soldering for potential problems, 
and if you find none, ask pa...@elecraft.com for a replacement KAT2 
firmware IC and a new resonator.

73,
Don W3FPR

On 5/2/2011 11:54 AM, Peter Wierach wrote:
> Hi,
>
> I need some help. I just finished KAT2 and got a lot of problems. Befor
> I explain,
> I get the message E000 in the menu, what does it mean?
> Is there a problem with the MCU?
>
> 73 Peter, DF8BB
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Re: [Elecraft] kat2 question

[Don Wilhelm]

  Dan,

That is quite normal.

73,
Don W3FPR

On 1/9/2011 2:58 PM, Dan Grizzard wrote:
> Hello all,
> I have completed the assembly of my kat2 and am at the testing phase. The 
> question is: I hear relay clicking when going thru the display settings for 
> L0-L8, C0-C8, N1&  N2, but NOT for
> CALn,CALP, CALS, AUTO, ALT and POUT.  Is this normal?
> Thanks in advance
> 73
> Dan
>
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Re: [Elecraft] kat2

[Don Wilhelm]

  Dan,

The trimmer pots are OK, use the 150k value.
The capacitors are a different matter, there are two that must fit 
between the processor socket and the header to the L/C board.  The .001 
uF capacitors seem to have become "fatter" over the years due to 
manufacturing changes.  Check to see if you have 2 extra .001 uF 
capacitors somewhere in the kit.  As I recall, there were 2 disc 
ceramics in the last KAT2 kit I built (but then I may have pulled them 
out of my parts drawer, my memory can be "fuzzy".

There was a period of time when the errata sheet was included, but the 
parts ECO had not yet been updated.  So if you purchased the kit a few 
months ago and are just now getting around to building it, you may 
indeed have those capacitors missing - if so, contact 
pa...@elecraft.com.  Explain carefully so that you receive the thin 
capacitors  There is no part number given in the errata sheet, but I 
know PN E530072 will work just fine even if you have to form the leads 
for the wider spacing.

73,
Don W3FPR

On 1/2/2011 11:58 AM, Dan Grizzard wrote:
> Hello all,
>
> I just started the inventory of parts for my kat2 and all is going well until 
> I got to the "102" caps. For the life of me I cannot determine the two 
> smaller ones!
> I have lined them up with a ruler on a marble top table and looked at them 
> from all angles. All 26 appear to be the same size. Any suggestions?
>
> Secondly, thetwo  trimmer potentiometers are listed at 100k but 150k was 
> shipped. A problem?
> 73 all
> Dan
>
> Daniel Grizzard
> Extra Class
> af4lb
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Re: [Elecraft] kat2

[Byron Servies]

A suggestion from QST I have used with success is to photograph the
parts with a digital camera on it's highest resolution setting and
enlarge them on the computer.

Just be sure not to get too close or your lens may not be able to
focus. If you have a macro setting, that can help too. Don't worry
about being a foot or two away: modern cameras can make the tiniest
part large.

73, Byron N6NUL

On Sunday, January 2, 2011, Dan Grizzard  wrote:
> Hello all,
>
> I just started the inventory of parts for my kat2 and all is going well until 
> I got to the "102" caps. For the life of me I cannot determine the two 
> smaller ones!
> I have lined them up with a ruler on a marble top table and looked at them 
> from all angles. All 26 appear to be the same size. Any suggestions?


-- 
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- CU in the 2011 Cal QSO Party 1-2 Oct 2011
- www.cqp.org
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Re: [Elecraft] kat2 or ssb module first?

[Don Wilhelm]

  Dan,

Not to worry, those options are independent of each other.  Do them in 
whichever order suits your fancy.

73,
Don W3FPR

On 12/30/2010 8:28 PM, Dan Grizzard wrote:
> I have my K2 up and running nicely now for several months and now want to 
> build
> and install my ssb and automatic tuner modules. Any suggestions which to do 
> first?
> I don't want to have to remove one to install the other.
> 73
> Dan
>
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Re: [Elecraft] KAT2: voltage reading

[Dr. Werner Furlan]

Don, 

thank you - everything looks fine. The tuner seems to work. 

73! de Werner OE9FWV


Don Wilhelm schrieb am 25 Nov 2010 um 19:59:

>   Werner,
> 
> You have obtained a better than normal adjustment - normally 008 and 
> above is considered OK.  I believe there is a statement to that effect
> somewhere in the manual.
> 
> I would guess that the 2.4 volts is OK.  That may change when you finish
> the power calibration.  Connect R6 (47 ohms if the K60XV is not installed,
> or 470 ohms with the K60XV) and see what happens.
> 
> 73,
> Don W3FPR
> 
> On 11/25/2010 6:03 PM, Dr. Werner Furlan wrote:
> > I am in the course of finishing the KAT2 assembly.
> >
> > I did the C55 adjustment like discribed on page 16:
> > Press T U N E button and release it when you see the display change.
> > Adjust C55 for an indication as close as possible to 0 0 0 . Tap or hold
> > T U N E again to cancel the C A L n display and return to receive mode
> >
> > I get as close as 007 - is this normal or indicating a problem?
> >
> > next question:
> >
> > On page 17 of the assembly manual at this point:
> > --
> > Go into TUNE mode briefly. At 5 watts, the voltage should be between 3
> > and 4 volts. If it is much lower or higher than this, you probably have a
> > wiring error in the SWR bridge. Remove the KAT2 control board from the
> > L-C board and check the wiring of T1. Make sure T1's leads are properly
> > stripped. --
> >
> > I have a reading of only 2.4 V. I checked the T1 wiring but do not see a
> > mistake. Should I go on and add R6 or should I remove T1 and check it
> > outside the board?
> >


-- 
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Re: [Elecraft] KAT2: voltage reading

[Don Wilhelm]

  Werner,

You have obtained a better than normal adjustment - normally 008 and 
above is considered OK.  I believe there is a statement to that effect 
somewhere in the manual.

I would guess that the 2.4 volts is OK.  That may change when you finish 
the power calibration.  Connect R6 (47 ohms if the K60XV is not 
installed, or 470 ohms with the K60XV) and see what happens.

73,
Don W3FPR

On 11/25/2010 6:03 PM, Dr. Werner Furlan wrote:
> I am in the course of finishing the KAT2 assembly.
>
> I did the C55 adjustment like discribed on page 16:
> Press T U N E button and release it when you see the display change.
> Adjust C55 for an indication as close as
> possible to 0 0 0 . Tap or hold T U N E again to cancel the C A L n
> display and return to receive mode
>
> I get as close as 007 - is this normal or indicating a problem?
>
> next question:
>
> On page 17 of the assembly manual at this point:
> --
> Go into TUNE mode briefly. At 5 watts, the voltage should be between 3 and
> 4 volts. If it is much
> lower or higher than this, you probably have a wiring error in the SWR
> bridge. Remove the KAT2 control
> board from the L-C board and check the wiring of T1. Make sure T1's leads
> are properly stripped.
> --
>
> I have a reading of only 2.4 V. I checked the T1 wiring but do not see a
> mistake. Should I go on and add R6 or should I remove T1 and check it
> outside the board?
>
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Re: [Elecraft] KAT2 Error code 202

[Paul Huff]

In case anyone in the future has the same question, here is a follow-up for the 
archive:

According to Gary at Elecraft error code 202 in the KAT2 submenu is a "normal 
result code."  So all is well.

73,
Paul - N8XMS

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Re: [Elecraft] KAT2 Error code 202

[Ed Lambert]

Please note that I also receive this error code on my KAT2 (202).

 

I have successfully gone through all of the testing steps to ensure that
each inductive and capacitive component is available and can be switched
into and out of the circuit. It is my impression, however, that the tuner
unit does not work as well as it did when first installed. Some relatively
simple loads will not tune below, say, 1.8 - 2.0 to 1.

 

Ed Lambert KD3Y

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Re: [Elecraft] KAT2 Error code 202

[Don Wilhelm]

Paul,

To the best of my knowledge, E202 would be something that the KAT100 
might display, but not the KAT2.  Perhaps someone got the firmware 
stickers wrong.
I think you should send a note to supp...@elecraft.com.

73,
Don W3FPR

Paul Huff wrote:
> My recently installed KAT2 indicates an error code of 202.  The manual says 
> that 
> error codes for the ATU range from 0 to 199.  Does an error code of 202 
> indicate 
> anything?
>
> Thanks in advance for any replies.
>
> 73,
> Paul - N8XMS
>
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Re: [Elecraft] KAT2 ERRATA

[lstavenhagen]

I just got through with my KAT2 and had the same issue. Before actually
getting on the phone with Elecraft, tho I temporarily fitted the socket and
header on the board and trial fitted each .001 cap one-by-one to see if any
of them would be thin enough to fit. I did find 4 that just baaarely fit in
the gap, so I went ahead with the build. I still ended up having to force
the header just a little bit to get it vertical, squeezing the cap a bit
between it and the socket. But it came out ok so I wasn't worried and just
kept going
. 
This seems like a goof in the KAT2 kit to me as most the .001's definitely
are too fat to fit in the gap.

Once done and put in the rig, the tuner works great. My T1 I'll be using
with my K3 so I needed another for the K2. Since it's going portable just
decided to put in the internal

LS
-- 
View this message in context: 
http://n2.nabble.com/KAT2-ERRATA-tp4768799p4769564.html
Sent from the Elecraft mailing list archive at Nabble.com.
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Re: [Elecraft] KAT2 ERRATA

[Don Wilhelm]

George,

The problem was the thickness of the capacitors.  The normal .001 uF 
capacitors from the manufacturer got thicker at some point and the new 
capacitors were too thick to physically fit on the Control Board between 
the U1 socket and the J4 header.

The last KAT2 that I built had 2 extra .001 uF capacitors in the bag 
that were not as thick.  Complete your inventory and see if you have 2 
extras in your kit.

It may be that Elecraft has eliminated the problem by changing the 
capacitor vendor and someone forgot to update the errata sheet.
If you do not have two extra caps, it would be best to call Elecraft 
(831) 763-4211 and talk with Scott about it.

Or, you can just build the KAT2 - but do not install C45 and C60 until 
after you have mounted the U1 socket and J4.  If you can physically put 
the capacitors in after those components are mounted, then all is well.  
If you choose this later method, be certain to write yourself a reminder 
note to install C45 and C50 lest you forget.

73,
Don W3FPR

w2b...@aol.com wrote:
> Says caps C45 & C60 are smaller. The caps I rcvd are all  the same size. 
> (26 pcs)  Do I need to send for smaller  caps?   tnx
>  
> George/W2BPI
>   
>
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Re: [Elecraft] KAT2 Debate

[John]

At 02:55 PM 11/09/09, you wrote:
>   Not sure what if anything am
>missing by not having an autotuner installed in the K2.  Any advice?  73,
>Curt KB5JO

Curt,

I have the KAT2 in each of my K2's. I usually have them in line. 
However, the main reason I have them is because they provide a port 
for a second transmit/receive antenna. I suppose they provide some 
band pass isolation when in line.

John
k7up 

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Re: [Elecraft] KAT2 Power problem (more)

[dw]

Hi Tom,
You've probably done all of this, but just to run over some of it.

Have you tried putting a dead short to ground on the + pin (3) of U4?
Check the output, it should follow.
Best to confirm this with R6 out of the circuit.
The old LM234 op amps were a bi-polar technology and they would
sometimes crow-bar.
I didn't dig that far into the LM358 datasheet, but its a slight
possibility even with a new chip.

Did you check C52 to see if the residual voltage is present also there?
Check pins 5 & 6 of U4, verify ~.1 ohms to ground.
Pin 7 of U4 should ~ 0 volts.

Can you unplug J3 Aux-bus?
If so, check to see if the voltage is still present at R6 with it
disconnected.
If not, the residual voltage is coming from the aux bus.

Just for giggles, check pins 2 & 5 on J3 Aux bus, verify ground.

Have you been using the KAT2 successfully until now, or is this a
installation from a build?
If so, is there any residual flux on the PCB in the pin areas of the
circuit?

Hope those suggestions help :)

Duane
N1BBR






To the list - I have yet to solve my problem with my KAT2.  So far I
have
replaced T1 which yielded the correct 3.4v on TX on the input to U4 and
0.74v on RX.  Unfortunately U4 was not buffering that through to R6 so I
replaced U4.  I now see the 3.4v on R6 in TX BUT 2.4v in RX.  I have yet
to
find where this 2.4v is coming from.  NOTE: this is present even when R6
is
not connected to the board.  Obviously when R6 is in line, it blanks the
receiver due to the high voltage on it.

I'm already in deep correspondence with Don and Gary but if you have any
ideas please do not hesitate to drop one to me as well...

Thanks and wish us luck!

Tom W0EA
-- 
 bw...@fastmail.net

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Re: [Elecraft] KAT2 Power problem continued

[Don Wilhelm]

Tom,

With R6 out, and DC voltage on U4 pin 3, but 0 volts on U4 pin 1, you 
certainly can suspect that U4 is toast. Unless you have a solder bridge 
between U4 pins 2 and 3 *and* no connection between pins 1 and 2 - that 
would be 2 failures, and we normally expect only a single failure, so a 
bad U4 is the most likely answer.

Do the test again, but this time measure the voltage at U4 pin 3.  If 
that is different than the voltage at U4 pin 1, you have a problem with 
U4.  (BTW, with 5 watts through the wattmeter, U4 pin 3 should measure 
between 3 and 4 volts).  As I stated, U4 is a unity gain op amp, and the 
voltage at the output should be the same as the voltage at the input - 
that is the behavior of a working unity gain op amp.

73,
Don W3FPR

Tom Campie wrote:
> As per Gary's suggestion, I removed and rewound T1.  I also reflowed all the
> joints in the SWR bridge and on U4.  With R6 out, I still measure 0.0 V and
> with it in I'm still under 3 v.  With it in, I read the same 2.4V as before.
>  While I can't confirm the actual output power exactly, my MFJ tuner reads 5
> watts when it is tuned (I don't have an RF probe or wattmeter yet - I'm
> getting the parts for the RF probe on Thursday)   Could it be that U4 is
> bad?  Amps like that don't break very easily.
> Still not sure where to look except U4 I guess...
>
> Tom
>
> On Tue, Jul 21, 2009 at 8:47 PM, Don Wilhelm  wrote:
>
>   
>> Tom,
>>
>> The voltage at U4 pin 3 should be between 3 and 4 volts with 5 watts of
>> power flowing through the wattmeter section of the KAT2 *and* with the FWD
>> potentiometer (R1) fully clockwise.
>>
>> U4 is configured as a unity gain op amp, and the voltage at the output (pin
>> 1)should be equal to the voltage at the input (pin 3).  If it is not, check
>> the soldering at U4.  That should be true whether R6 is connected or not.
>>
>> If the conditions (and results) are not as stated, then as the manual
>> states, check T1, D1, C50, C52 and R1 for good soldering.  Count the turns
>> on T1 to be certain you have not wound an extra turn.
>>
>> Is the power that you are passing through the KAT2 equal to 5 watts?  How
>> are you determining it?
>>
>> 73,
>> Don W3FPR
>>
>>
>> Tom Campie wrote:
>>
>> 
>>> Still no solution for my power problem.  Some correspondence with Gary at
>>> Elecraft has me back where I started.  I removed R6 and saw 0V at the
>>> output
>>> of U4 but 2.5V on the input of U4 coming from U1 (pin 3 on U4).  According
>>> to the testing in the manual this should be 3-4 volts with a requested
>>> power
>>> of 5 watts.  I replaced R6 and now saw the 2.5V on the output of U4.  This
>>> is still low obviously.  I reflow'd all the solder joints in the SWR
>>> bridge
>>> as it suggests and this has not helped.  I'm not sure where to look next.
>>>
>>> Tom W0EA
>>>
>>>   
>
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Re: [Elecraft] KAT2 Power problem continued

[Tom Campie]

As per Gary's suggestion, I removed and rewound T1.  I also reflowed all the
joints in the SWR bridge and on U4.  With R6 out, I still measure 0.0 V and
with it in I'm still under 3 v.  With it in, I read the same 2.4V as before.
 While I can't confirm the actual output power exactly, my MFJ tuner reads 5
watts when it is tuned (I don't have an RF probe or wattmeter yet - I'm
getting the parts for the RF probe on Thursday)   Could it be that U4 is
bad?  Amps like that don't break very easily.
Still not sure where to look except U4 I guess...

Tom

On Tue, Jul 21, 2009 at 8:47 PM, Don Wilhelm  wrote:

> Tom,
>
> The voltage at U4 pin 3 should be between 3 and 4 volts with 5 watts of
> power flowing through the wattmeter section of the KAT2 *and* with the FWD
> potentiometer (R1) fully clockwise.
>
> U4 is configured as a unity gain op amp, and the voltage at the output (pin
> 1)should be equal to the voltage at the input (pin 3).  If it is not, check
> the soldering at U4.  That should be true whether R6 is connected or not.
>
> If the conditions (and results) are not as stated, then as the manual
> states, check T1, D1, C50, C52 and R1 for good soldering.  Count the turns
> on T1 to be certain you have not wound an extra turn.
>
> Is the power that you are passing through the KAT2 equal to 5 watts?  How
> are you determining it?
>
> 73,
> Don W3FPR
>
>
> Tom Campie wrote:
>
>> Still no solution for my power problem.  Some correspondence with Gary at
>> Elecraft has me back where I started.  I removed R6 and saw 0V at the
>> output
>> of U4 but 2.5V on the input of U4 coming from U1 (pin 3 on U4).  According
>> to the testing in the manual this should be 3-4 volts with a requested
>> power
>> of 5 watts.  I replaced R6 and now saw the 2.5V on the output of U4.  This
>> is still low obviously.  I reflow'd all the solder joints in the SWR
>> bridge
>> as it suggests and this has not helped.  I'm not sure where to look next.
>>
>> Tom W0EA
>>
>>
>
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Re: [Elecraft] KAT2 Power problem continued

[Don Wilhelm]

Tom,

The voltage at U4 pin 3 should be between 3 and 4 volts with 5 watts of 
power flowing through the wattmeter section of the KAT2 *and* with the 
FWD potentiometer (R1) fully clockwise.

U4 is configured as a unity gain op amp, and the voltage at the output 
(pin 1)should be equal to the voltage at the input (pin 3).  If it is 
not, check the soldering at U4.  That should be true whether R6 is 
connected or not.

If the conditions (and results) are not as stated, then as the manual 
states, check T1, D1, C50, C52 and R1 for good soldering.  Count the 
turns on T1 to be certain you have not wound an extra turn.

Is the power that you are passing through the KAT2 equal to 5 watts?  
How are you determining it?

73,
Don W3FPR

Tom Campie wrote:
> Still no solution for my power problem.  Some correspondence with Gary at
> Elecraft has me back where I started.  I removed R6 and saw 0V at the output
> of U4 but 2.5V on the input of U4 coming from U1 (pin 3 on U4).  According
> to the testing in the manual this should be 3-4 volts with a requested power
> of 5 watts.  I replaced R6 and now saw the 2.5V on the output of U4.  This
> is still low obviously.  I reflow'd all the solder joints in the SWR bridge
> as it suggests and this has not helped.  I'm not sure where to look next.
>
> Tom W0EA
>   
>
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Re: [Elecraft] KAT2 Power cal

[Tom Campie]

Thanks Don - My dummy load showed a 1:1 SWR on 40m with my last radio, but I
have not used an analyzer to look at it.  I suspect I'll be "close enough"
(or at least I hope it is!)  I think you are supposed to do the cal at 5
watts so no worries exceeding the power on the probe.

73 Tom

On Fri, Jul 17, 2009 at 9:58 AM, Don Wilhelm  wrote:

> Tom,
>
> Yes, you can use the RF probe.  It *should* be OK up to a max of 20 watts
> measuring across a 50 ohm dummy load.  The 1N34A diode is rated at 45 volts
> peak reverse voltage, so if you exceed 30 volts RMS (the RF Probe reads in
> RMS volts), you are nearing the limit.
>
> The accuracy of your measurement depends on the accuracy of your dummy
> load.  It would be wise to check it with an antenna analyzer at the
> frequency you will be using for calibration (40 meters is preferred)
>
> 73,
> Don W3FPR
>
>
> Tom Campie wrote:
>
>> Hey guys, I'm going to finish my KAT2 tonight and I need to calibrate the
>> power and all that stuff.  I have a 50 ohm dummy load so the SWR cal is
>> good
>> but I dont have a power meter.  Can I use the RF probe that was made
>> during
>> the construction of the K2?  If so, is there some documentation somewhere
>> on
>> how to do that?  (note -I did not build my K2 so I have not used the
>> integrated test equipment)
>>
>> Tom W0EA
>>
>>
>
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Re: [Elecraft] KAT2 Power cal

[Don Wilhelm]

Tom,

Yes, you can use the RF probe.  It *should* be OK up to a max of 20 
watts measuring across a 50 ohm dummy load.  The 1N34A diode is rated at 
45 volts peak reverse voltage, so if you exceed 30 volts RMS (the RF 
Probe reads in RMS volts), you are nearing the limit.

The accuracy of your measurement depends on the accuracy of your dummy 
load.  It would be wise to check it with an antenna analyzer at the 
frequency you will be using for calibration (40 meters is preferred)

73,
Don W3FPR

Tom Campie wrote:
> Hey guys, I'm going to finish my KAT2 tonight and I need to calibrate the
> power and all that stuff.  I have a 50 ohm dummy load so the SWR cal is good
> but I dont have a power meter.  Can I use the RF probe that was made during
> the construction of the K2?  If so, is there some documentation somewhere on
> how to do that?  (note -I did not build my K2 so I have not used the
> integrated test equipment)
>
> Tom W0EA
>   
>
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Re: [Elecraft] KAT2 question abt voltage at U4, pin7

[Don Wilhelm]

Check the actual power with an external wattmeter - set the power 
control to 5 watts and transmit, then tell us if the actual power is 
near 5 watts or near the maximum power (12 watts or over).

It is possible that U4 is faulty.  Pin 7 is not used - there are 2 op 
amps in the LM358 package, so if the one having its output at pin 1 is 
OK, power will be controlled and it does not matter what pin 7 does 
because it is connected to nothing.  The power output check above will 
tell if the output at U4 pin 1 is working.

73,
Don W3FPR


kc9...@aol.com wrote:
> After a recent calamity while attempting PSK31, where I introduced 
> 13.5v into microphone jack pin 6 (a 5v line), repairs have been made, 
> and I have made contacts in both cw and ssb modes.
>  
> However, I seem to be getting more HI CURRENT warnings on bands and at 
> power levels where previously, I did not.
>  
> I re-initialized the KAT2, and, as I cycle through L0-L8 and C0-C8, 
> all relays provide a nice click.
>  
> I performed the dc voltage checks at the bottom of KAT2 manual, page 
> 22.  Everything was fine, except for U4, pin 7 where I got a reading 
> of 4.74v instead of the 0v or nearly 0v that the manual implies I 
> should see.  Could this be the cause of the HI CURRENT warnings?
>  
> Thanks for your 
> consideration.73, 
> Jef Fox kc9gbx
>
> 
> Great Deals on Dell Laptops. Starting at $499. 
> 
>  
>
> 
>
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Re: [Elecraft] KAT2 and CALS

[Phillip Heller]

I was actually referring to the SWR calibration step near the end of  
"Power Calibration" in the build document, which is against the 50 ohm  
dummy load.

However, it's really of no concern now, as I re-calibrated today  
against a different dummy load using a known accurate SWR meter and  
got 1.0:1 on all but 10m (where I got 1.1:1).

Thanks for the reply!

--phil

On Jan 24, 2009, at 8:29 AM, Don Wilhelm wrote:

> Phil,
>
> If the SWR after a TUNE is not low enough for your tastes, just try  
> doing it again, it often finds a better match.  There is also the  
> ALT setting which uses a more refined algorithm, but takes longer.
>
> It may also be that the load is outside the range of the KAT2 on  
> some bands - while the KAT2 has a wide matching range, it does have  
> its limits.  Very high impedance loads do give it difficulty.  You  
> can try adding or subtracting some feedline (1/8 wavelength at a  
> time for the band having difficulty) to see if you can produce a  
> better compromise antenna system input impedance.
>
> 73,
> Don W3FPR
>
> Phillip Heller wrote:
>> So I've completed the KAT2, so far so good.
>>
>> I get C55 to 003 +/- 2 (bounces back and forth).  R1 set per DL1   
>> calculation, R2 set with matching wiper resistance.
>>
>> CALS reports 1:1 on 80 and 40, though from 30 through 10 it  
>> reports  from 1.1:1 to 1.9:1 respectively.
>>
>> The documentation says not to expect 1.0:1 on the higher bands,  
>> though  1.9:1 does seem pretty high.
>>
>> Any ideas?
>>
>> --phil
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Re: [Elecraft] KAT2 and CALS

[Don Wilhelm]

Phil,

If the SWR after a TUNE is not low enough for your tastes, just try 
doing it again, it often finds a better match.  There is also the ALT 
setting which uses a more refined algorithm, but takes longer.

It may also be that the load is outside the range of the KAT2 on some 
bands - while the KAT2 has a wide matching range, it does have its 
limits.  Very high impedance loads do give it difficulty.  You can try 
adding or subtracting some feedline (1/8 wavelength at a time for the 
band having difficulty) to see if you can produce a better compromise 
antenna system input impedance.

73,
Don W3FPR

Phillip Heller wrote:
> So I've completed the KAT2, so far so good.
>
> I get C55 to 003 +/- 2 (bounces back and forth).  R1 set per DL1  
> calculation, R2 set with matching wiper resistance.
>
> CALS reports 1:1 on 80 and 40, though from 30 through 10 it reports  
> from 1.1:1 to 1.9:1 respectively.
>
> The documentation says not to expect 1.0:1 on the higher bands, though  
> 1.9:1 does seem pretty high.
>
> Any ideas?
>
> --phil
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Re: [Elecraft] KAT2 bridge null adj.

[Don Wilhelm]

Allan,

Do you actually have power flowing through the KAT2?  Power is necessary 
to generate voltage at the diodes D1 and D2 cathodes.
If you can temporarily connect an external wattmeter between the KAT2 
and the dummy load, see if power is getting through.
Once you determine that there is power flowing out of the KAT2, remove 
the external wattmeter before attempting to set C55 to its final setting.

If you do have power flowing and still have a display of 000, be certain 
you have the potentiometers set to full clockwise (max rotation).  Check 
the orientation of D1 and D2 and look for soldering problems.
Measure the DC voltage at the wiper of R2 - If you have voltage at the 
wiper of R2, but still a zero display there is a problem between R2 and 
pin 4 of U1.

73,
Don W3FPR

Allan Glasdam wrote:
> Hi guys
> After receiving great help from Don off list with the KAT2, I have a new 
> "problem"
> KAT2 assembly and operating instruction page 16, second from bottom 
> says: adjust C55.  Hold in TUNE button and release when...
> Adjust C55 as close as possible to 000.
>
> When I press TUNE the display flashes ATu and then reads 000 constantly 
> until I tap menu. It´s not possible to get any movement when turning C55.
> T1 on KAT2 is rewound, soldered and checked.
> Any suggestions? I would be glad for a hint, where to search.
> 73
> Allan OZ8A
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Re: [Elecraft] KAT2 J8 tolerance?

[Johnny Siu]

Yes, I have the same experience in my latest KAT2 as well.
 
Johnny Siu VR2XMC

--- 2009年1月23日 星期五，Phillip Heller  寫道﹕

寄件人: Phillip Heller 
主題: [Elecraft] KAT2 J8 tolerance?
收件人: elecraft@mailman.qth.net
日期: 2009 1 23 星期五 下午 2:07

Just finished the KAT2 for K2 #6662.

Unfortunately, J8 is just too tight on CTRL P4.  I *might* be able to  
force it on, but it would never come off.

Anyone run into this?

--phil
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Re: [Elecraft] KAT2 J8 tolerance?

[Don Wilhelm]

Phil,

Yes, it is a tight fit with those many pins, but it will go on, and it 
will come off too.  Make certain all the pins are started before 
applying pressure and apply pressure from both ends of the board.
To remove it, 'wiggle' the ends of the boards alternately so it is 
removed straight.
It requires less force after 2 or 3 times.

73,
Don W3FPR

Phillip Heller wrote:
> Just finished the KAT2 for K2 #6662.
>
> Unfortunately, J8 is just too tight on CTRL P4.  I *might* be able to  
> force it on, but it would never come off.
>
> Anyone run into this?
>
> --phil
>   
>
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Re: [Elecraft]KAT2 not switching antennas after precipitation static event

[Don Wilhelm]

Arthur,

I believe you are on the right track in suspecting the firmware.  I 
would simply obtain a replacement chip from Elecraft and change it - 
that is the only way to be certain unless you have access to a digital 
'scope that can record the latching pulses for the latching relays.  It 
is very difficult to tell what is going on with an analog 'scope display 
since the latching action is a one-time occurrence with each cycle of 
the ANT1/2 pushbutton.


73,
Don W3FPR

Arthur Gunn wrote:
Initially this KAT2 worked well, switching between ant1 & ant2. During 
a lighthouse portable weekend, in hard driving rain, it may have 
suffered from a precipitation static discharge via the connected 
antenna. Since then, ant2 is always connected. The K-2 (#6155) 
otherwise operates normally.


Believing that relay K18 may have had contacts damaged, it has been 
replaced but with no change in operation.


Operating the switch for ant1 to ant2 results in a relay operation 
sound. Measuring the contacts confirms that the K-18 does not change 
position. The tune function operates normally.


In troubleshooting, the DMM indicates the K-18 coil pin 10 to ant 
connector shell ground reads 208 ohms while the same reading for K-17 
shows 24 ohms.


While tuning the connected antenna: K-18 coil pin 10 to pin 1 reads a 
transient 200 mV and K-17 similar reading is a transient 10 mV. The 
two relay coils measure about 245 ohms each.


Should I assume that U1 is failing to provide the signal to K-18 and 
the relay sound is from another relay possibly also due to U-1 fault?


Your thoughts are appreciated.



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Re: [Elecraft] KAT2: Power Calibration Problem

[David Woolley (E.L)]

Don Wilhelm wrote:

Also, be certain that your RF Probe is a type that provides RMS 
readings.  Some (those with the diode connected in series with the meter 
probe) will indicate peak voltage.  At 5 watts, 15.8 volts is the 


Surely any simple diode based design is peak reading, whether the diode 
is series or parallel.  To get true RMS, you either have to assume a 
sine wave, and use a voltage divider, or you need to integrate the 
square of the instantaneous voltage, by using thermal effects, using 
square law detectors, or by integrating digitally.



--
David Woolley
"The Elecraft list is a forum for the discussion of topics related to 
Elecraft products and more general topics related ham radio"

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Re: [Elecraft] KAT2: Power Calibration Problem

[Don Wilhelm]

Steve,

Set the menu ATU parameter to CAL P when adjusting R1 for the power 
reading.  CAL S is the setting used to align the SWR (use a dummy load 
which will provide a known SWR such as a 25 ohm or 100 ohm load which 
give a 2.0 SWR).


Also, be certain that your RF Probe is a type that provides RMS 
readings.  Some (those with the diode connected in series with the meter 
probe) will indicate peak voltage.  At 5 watts, 15.8 volts is the 
correct voltage for an RMS reading probe across a 50 ohm load, but if 
your probe indicates peak voltage, you must adjust for 22.36 volts minus 
the diode voltage drop.  If you are looking at an oscilloscope, you will 
see a peak to peak voltage and that should be 44.72 volts for 5 watts.


Consider how you checked your dummy load?  If you checked it with an 
ohmmeter, that is the value at DC, but the value at any given frequency 
may be different - check it with an antenna analyzer to be certain.


73,
Don W3FPR

list1 wrote:

Hi all,
I decided to realign my ole trusty KAT2.

Adjusting the bridge null seemed to go OK.  However, when I adjust the power 
knob to give 15.8 Volts (5 Watts) at my precision dummy load (50.3 Ohms), 
turning R1 clockwise to the maximum position only shows 4.4 Watts on the CAL S 
readout.

Any suggestions?

  

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Re: [Elecraft] KAT2 CALIBRATION - R 1 & 2

[Don Wilhelm]

Chris,

You did not say, but I assume you must have the KAT2 set for CALP mode.  
The 0.0r indication shows that there is zero reflected power, which is 
correct if you are operating into a good 50 ohm dummy load..


Switch to CALS and you should see an SWR indication of 1.0 to 1.

Simply use the manual instructions to set R2 to the same relative 
position as R1 and the tuner will work fine.  If you wish to actually 
calibrate the SWR indication, you will need dummy loads that have a 
specific resistance (and zero reactance).  I use 25 ohm and 100 ohm 
loads to properly calibrate the wattmeter SWR calibration, but without 
those tools, just set the potentiometers to match.


73,
Don W3FPR

MTcja wrote:

I am in the process of calibrating the tuner.  I think that I have R1 set
using an external meter.  However, with full deflections of R2, the LCD
indication does not move from "0.0r".  Using my DMM to measure resistance of
R1 at the center terminal I got 36.0k.  The closest I could get with R2 was
36.08k (not in TUNE mode).  Please let me know what to do to resolve this
issue.  Thanks again for all the help as I approach completion.

  


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Re: [Elecraft] KAT2 INSTALL - VOLTAGE AT U4, PIN1

[MTcja]

Don:

Thanks again.  Good news.  And thanks for the hint I do have the k60xv to
install so this is a big help.  I am kind of going by guess and by golly on
what order I install things.  I have started with the KAT2 and had planned
to move to the SSB2, but I may do the 160m accessory first.  Suggestions
always appreciated.

73's
Chris

Don Wilhelm wrote:
> 
> Chris,
> 
> Unless you are really careful with your DMM leads and have zeroed your 
> DMM, *any* reading of .001 volts (or even up to .003) can be considered 
> zero under normal conditions because it is likely noise being coupled 
> onto the DMM leads from sources unknown.
> 
> So, yes, that is close enough to zero.
> 
> Additional hint: if you are ever going to install the K60XV, use a 470 
> ohm resistor at the R6 location rather than the 47 ohm value.  If you 
> have the K60XV in hand, you will find an extra 470 ohm resistor just for 
> that purpose packaged with the kit.
> 
> 73,
> Don W3FPR
> 
> MTcja wrote:
>> After listening for a while and reviewing basic and advanced operation I
>> am
>> now beginning the install of the K2 accessories.  For the KAT2 I am
>> getting
>> .001 V at U4/PIN 1.  Is this "close enough" to zero?  If not, please
>> advise
>> the best way to trace back the origin of this voltage.  BTW, in TUNE I am
>> at
>> 3.8.  Thanks.  
>>   
>>
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-- 
View this message in context: 
http://www.nabble.com/KAT2-INSTALL---VOLTAGE-AT-U4%2C-PIN1-tp17115482p17116537.html
Sent from the K2 mailing list archive at Nabble.com.

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Re: [Elecraft] KAT2 INSTALL - VOLTAGE AT U4, PIN1

[Don Wilhelm]

Chris,

Unless you are really careful with your DMM leads and have zeroed your 
DMM, *any* reading of .001 volts (or even up to .003) can be considered 
zero under normal conditions because it is likely noise being coupled 
onto the DMM leads from sources unknown.


So, yes, that is close enough to zero.

Additional hint: if you are ever going to install the K60XV, use a 470 
ohm resistor at the R6 location rather than the 47 ohm value.  If you 
have the K60XV in hand, you will find an extra 470 ohm resistor just for 
that purpose packaged with the kit.


73,
Don W3FPR

MTcja wrote:

After listening for a while and reviewing basic and advanced operation I am
now beginning the install of the K2 accessories.  For the KAT2 I am getting
.001 V at U4/PIN 1.  Is this "close enough" to zero?  If not, please advise
the best way to trace back the origin of this voltage.  BTW, in TUNE I am at
3.8.  Thanks.  
  


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Re: [Elecraft] KAT2: SWR Accuracy

[Don Brown]

Hi

Your numbers look normal to me. You may be able to improve the calibration 
using a 100 and 25 ohm load. This is how I do the calibration.


First get it into the ball park with the manual calibration method
Then alternate with the 100 and 25 ohm load and adjust C55 to get the same 
reverse reading
Increase the reverse pot to indicate 2.0 SWR and check at both loads for the 
same reading tweak C55 if needed
Go back and adjust the forward power to agree with your external calibrated 
meter with a 50 ohm load
Check the 25 and 100 ohm SWR readings again for a 2.0 value. The forward and 
reverse settings will interact so you may need to do all of the above 
several times to get it set up correctly.


Your loads should not have cables connected to them. They should connect 
directly to the tuner connectors. I built my loads into standard UHF 
connectors (PL-239) and use BNC adapters for the KAT2 or directly for the 
KAT100. I used two 51 ohm in parallel for the 25 ohm,  one 100 ohm for the 
100 ohm load and two 100 ohm resistors in parallel for the 50 ohm load. The 
resistors are 2 and 5 watt MOS types and mounted inside the connector. It is 
OK to use a cable with the 50 ohm load when using the WM-2 but as a final 
check I connect the 50 ohm load directly to the KAT2 and check for a 1.0:1 
reading


Thanks

Don Brown
KD5NDB

K3 S/N  0575

--
From: "Michael Linden" <[EMAIL PROTECTED]>
Sent: Tuesday, April 08, 2008 7:02 AM
To: 
Subject: [Elecraft] KAT2: SWR Accuracy

 I've just completed alignement of my KAT2 and am a bit dismayed by its 
SWR accuracy.


   I feel pretty confident that I found the true dip in C55 at a value of 
12. I then aligned the forward power (R1) using an OHR WM-2 that was 
aligned on 40m against test equipment. The 50 Ohm dummy load I'm using 
reads a flat 1.0:1 up into the 2m region on an MFJ-259B. I'm fairly happy 
with the forward calibration which yielded the following results:


 BAND  K2WM-2
 160  4.4   5.0
 804.6   5.0
 404.9   5.0
 305.2   5.0
 204.9   4.9
 175.0   5.0
 155.1   4.9
 125.5   5.0
 105.6   5.0

   I initially calibrated reflected power (R2) by measuring the 
wiper-to-ground resistance on R1 and setting R2 for the same 
wiper-go-ground resistance. The reflected calibration results range from 
1.0:1 on 160m to 1.2:1 on 10m into the 50 Ohm dummy load. However, the SWR 
readings I see when using a 25 Ohm dummy load (confirmed on MFJ-259B) 
aren't very good. The KAT2's 25 Ohm dummy load readings range from 1.7:1 
on 160m to 1.2:1 on 10m.


   Given the preceding results, I decided to set the reflected adjustment 
(R2) to show 2.0:1 on 40m into the 25 Ohm dummy load. This time, the 
results varied from 2.1:1 on 160m to 1.3:1 on 10m. I have considered going 
back and readjusting R2 to show an average reading of 2.0:1 across the 
bands into the 25 Ohm load (higher than 2.0:1 on 160m, lower than 2.0:1 on 
10m -- a compromise).


   Is the accuracy displayed above typical of the KAT2? If not, maybe I 
need to go back and reevaluate my C55 calibration (although I felt pretty 
confident that it is correct).


   Thanks, Michael N9BDF, K2 #4137
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Re: [Elecraft] KAT2 without balun - which doublet length is better?

[David Woolley]

ub5_073_oleg wrote:


I'm going to use my K2 with KAT2 internal ATU to operate a
doublet from 80m to 10m including WARC bands without a
balun. Among others, Dave's W8FGU home page inspired me to
try this.

I hope this is not a problem, especially when battery-fed
during portable operation, as there is [almost] no
HF-connection to the ground (the whole system is 'floating')


Even though the case is floating, it doesn't avoid RF on the chassis 
problems.  Although the output transformer will see 50 ohms, the two 
legs of your doublet will have a much higher impedance which means that 
the RF output will cause the chassis voltage to vary by much more than 
would be implied by assuming half the power into 25 ohms.  Instead of 
under 10 volts, you are likely to get up to 100 or so volts.  I've found 
that to my cost with a short indoors doublet on 160m, even though it has 
a simple balun.


The high chassis voltage variations will drive any appendages, like 
battery cables, key cables, headphones, etc.


Unfortunately, for baluns to work well they really need to be on the 
transmitter side of the ATU, where they see about 50 ohms differential 
mode, and that isn't compatible with an internal ATU.


My current best guess as to what is needed is to tune out the reactive 
component of the ground side leg of the doublet, and therefore get the 
impedance down to 25 or less.  Logically this is equivalent to end 
feeding against a counterpoise, but, in my view, the distinction between 
a counterpoise and the other half of a doublet is somewhat artificial.


I haven't tried this in anger, and one question is how to determine when 
you have canceled the reactance.  The instructions for commercial 
"artificial earth" tuners tend to suggest tuning for maximum current, 
but, it seems to me that that can only be done if the formal ATU is 
tuned to cancel the reactance in the non-ground end.  As that setting, 
in turn depends on having zero reactance on the ground end, one, has an 
interdepence problem.


My question is: can/should I make it easier for KAT2, e.g.
choosing other antenna or feeder lentgh or maybe
adding/removing a piece of feeder on some bands? Are there
some proven length to use? 


The G5RV was designed to have a relatively good match on all the 
pre-WARC bands.


--
David Woolley
Emails are not formal business letters, whatever businesses may want.
RFC1855 says there should be an address here, but, in a world of spam,
that is no longer good advice, as archive address hiding may not work.
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RE: [Elecraft] KAT2 without balun - which doublet length is better?

[Dave Van Wallaghen]

Hi Oleg,

Well, I wish I could take credit for implementing this configuration, but it
was at the urging of Ron, AC7AC and Don, W3FPR who stated that if the
doublet was fairly well balanced, that connecting it directly to the KAT2
should work well and eliminate any losses due to the balun. There was a
pretty good discussion of this about a year ago I think.

The doublet I used was 66' across with about a 33' feeder. I was able to get
a good match 80m - 10m. The only bands I had some trouble tuning were 17m
and 12m. Again, at the suggestion of Ron, I added a 6 foot stub feeder and
got it to tune up pretty well on those bands.

I wish I could tell you that I modeled this setup and designed it to work
properly, but alas I did not. I simply built it up with convenient lengths
and stuck it up in a tree and had a ball with it all summer long. As I learn
more about antennas, I will surely come back and revisit it and try to
figure out why it seemed to work very well for me. 

One thing I did notice toward the end of summer and beginning of fall, is
that I started to have a harder time getting a match on 20m. My guess is
that as time and weather took some toll on the antenna that it became
somewhat unbalanced. It eventually succumbed to a branch knocking down one
leg after a nasty storm here and I took it down for the season. Looking
forward to putting it back up when the weather gets nice here. In fact, I'm
looking to use my K3 out there this summer as well. I just bought a solar
controller from Don Brown, KD5NDB, and may try to run the K3 (and K2) QRP
from a solar power configuration. Sounds like fun anyway.

If I can answer (unscientifically) any more questions, let me know.

Take care & 73,
Dave W8FGU

> -Original Message-
> From: [EMAIL PROTECTED] [mailto:elecraft-
> [EMAIL PROTECTED] On Behalf Of ub5_073_oleg
> Sent: Monday, March 17, 2008 5:22 PM
> To: elecraft@mailman.qth.net
> Subject: [Elecraft] KAT2 without balun - which doublet length is better?
> 
> Hi,
> 
> I'm going to use my K2 with KAT2 internal ATU to operate a
> doublet from 80m to 10m including WARC bands without a
> balun. Among others, Dave's W8FGU home page inspired me to
> try this.
> 
> I hope this is not a problem, especially when battery-fed
> during portable operation, as there is [almost] no
> HF-connection to the ground (the whole system is 'floating')
> 
> Quick modelling of 2x20m + 13.5m feeder antenna shows that
> KAT2 should be able to do the job, as its 20uH and 2400pF
> are enough on all bands.
> 
> My question is: can/should I make it easier for KAT2, e.g.
> choosing other antenna or feeder lentgh or maybe
> adding/removing a piece of feeder on some bands? Are there
> some proven length to use?
> 
> 73  Oleg
> 
> 
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Re: [Elecraft] KAT2 question

[geoff allsup]

Thanks to all who replied!  10 minutes after emailing, I found the answer in the manual!  A bit 
fuzzy with the flu here - maybe I should get some rest before I toast something in my K2!!!


geoff - W1OH

Ingo Meyer (DK3RED) wrote:

Hello Geoff,

I have a quick question, as I have been using an MFJ tuner to a 
balanced feedline on a doublet, and have not built a balun for the 
K2/KAT2 yet.  Is there a bypass mode for the KAT2 such that I can use 
an external tuner?  ATU AUTO, of course, causes the KAT2 to go thru a 
tune cycle when pressing the TUNE button on the K2.


Yes, its possible. If you use the KAT2 as SWR/wattmeter only, the 
matching network is disabled/bypassed. Switch your KAT2 via the menu to 
CALS (for SWR display) or CALP (for power meter).


--
*
Geoff Allsup, W1OH [EMAIL PROTECTED]  or  [EMAIL PROTECTED]
Research Engineer  Upper Ocean Processes Group
Woods Hole Oceanographic Institution   Woods Hole, MA, USA
*

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Re: [Elecraft] KAT2 question

[Ingo Meyer (DK3RED)]

Hello Geoff,

I have a quick question, as I have been using an MFJ tuner to a balanced 
feedline on a doublet, and have not built a balun for the K2/KAT2 yet.  
Is there a bypass mode for the KAT2 such that I can use an external 
tuner?  ATU AUTO, of course, causes the KAT2 to go thru a tune cycle 
when pressing the TUNE button on the K2.


Yes, its possible. If you use the KAT2 as SWR/wattmeter only, the matching network 
is disabled/bypassed. Switch your KAT2 via the menu to CALS (for SWR display) or 
CALP (for power meter).

--
72/73 de Ingo, DK3RED - Don't forget: the fun is the power!

[EMAIL PROTECTED] - www.qrp4fun.de
   DL-QRP-AG #824 - www.dl-qrp-ag.de
  QRP ARCI #11295 - www.qrparci.org
DARC #2360404 - www.darc.de

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Re: [Elecraft] KAT2 question

[David Pratt]

In a recent message, geoff allsup <[EMAIL PROTECTED]> wrote ...

Is there a bypass mode for the KAT2 such that I can use an external 
tuner?  ATU AUTO, of course, causes the KAT2 to go thru a tune cycle 
when pressing the TUNE button on the K2.


Yes, Geoff, you will have met that while building your K2.  If you want 
to bypass the ATU, in the menu set ATU Pout.


73
--
David G4DMP
Leeds, England, UK
--


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Re: [Elecraft] KAT2 ASSEMBLY MANUAL QUESTION

[Don Wilhelm]

John,

Yes, the manual is confusing - bottom line is that there should be one 
set of standoffs and one set of washers between the two boards - it 
matters not which end of the standoff the washers are installed.
To make things easiest, put one set of lockwashers (the first set 
installed) between the standoff and the board.  Put the second set of 
lockwashers under the screw-heads - it is much easier that way and it 
works fine.
The manual will be updated to correct this confusion - as soon as Ron 
gets a break from the K3 and finishes up the K2 manual updates.


73,
Don W3FPR

John Mahon wrote:

Hi group.

I just assembled and installed a KAT2 module into my K2/QRP #5949. It seems to 
be working fine.

On page 6, the 6th step instructs you to install the two standoffs onto the 
Control board. The illustration shows the washer between the standoff and PC 
board. I followed that instruction.

On page 12, the 4th step instructs you to secure the L-C board to Control board 
standoffs. The instruction continues "These lock washers go between the standoffs 
and the PC board, NOT between the PC board and screws as on the Control board."

  

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Re: [Elecraft] KAT2 Bump

[David Woolley]

Matt Palmer wrote:



KAT2 is built, however i cant get the 10pin connector to sit on p4 of
the control board, i dont want to force it, (right now i'm pushing
enough to flex the circuit board) is it supposed to sit flush or nott?


I found I had to force this connector on and that it wouldn't seat 
completely.  It appears to be the design of the contacts, which 
completely surround the pin and don't have room for expansion at the 
entry to the contact. I was concerned about stripping the plating on the 
pins after a few cycles.


However, I also bought the KIO2, so now this connector goes into the 
KIO2 connector board and the PC mounted female connector on the KIO2 
connector board has a contact design which doesn't have this problem.

--
David Woolley
Emails are not formal business letters, whatever businesses may want.
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Re: [Elecraft] KAT2 Bump

[Don Wilhelm]

Matt,

It does sit flush when fully seated.  You may have one of two problems.  
The first thing to check is your soldering of the individual sockets to 
the wires.  If you allowed solder to wick up into the socket area, you 
have plugged the hole for the pin and it will never fit fully on - it 
only takes one socket like that to cause fit problems.  The solution to 
this is simple (but not easy) - remove the soldered on sockets from the 
housing (it takes a small needle-point to depress the little tongue) and 
replace the troublesome socket with a different one.  To find any 
sockets that are solder filled, test each one for depth with a cut-off 
component lead - it should insert at least as far as the length of the 
pins on the header.


The problem also could be that you inserted all 10 sockets into the 
housing - just like the manual instructed, so great for you in following 
the instructions! , and they just are not fully aligned yet.


The fit with all 10 sockets installed is tight because all those 
connector sockets are new.  They will give some relief after a few times 
on and off the pins.  You can plug one row of sockets onto a row of the 
pins by offsetting the connector to one side and plugging it in (Be 
*certain* to remove the power from the K2 while doing that).  Do that on 
both sides - you might wiggle it back and forth a bit too to loosen 
things up and get all the sockets into alignment.


It will go on all the way once all the sockets are properly aligned and 
are pre-sprung.


73,
Don W3FPR



Matt Palmer wrote:

@don and the other guru's

KAT2 is built, however i cant get the 10pin connector to sit on p4 of
the control board, i dont want to force it, (right now i'm pushing
enough to flex the circuit board) is it supposed to sit flush or nott?


  

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Re: [Elecraft] KAT2: Can't Get Bridge Null Adjustment (C55) Below 012 mV

[Don Wilhelm]

Michael,

Although an absolute null would indeed be zero, the 10 to 12 range is 
about as low as you can get - the K2 display is reading in millivolts 
and there is some noise picked up and coupled into the op amp input 
which limits the low end of the reading capability.  The same problem is 
true when making any low level measurements. 

Try to fine the 'edges' of the indicated low point and set the capacitor 
halfway between.


The operation of the KAT2 will not be affected much at all - the result 
may be a slight error in the SWR indication.  Actually the null point is 
more dependent on the dummy load used during the process.  If you want 
the greatest accuracy, use a dummy load that is known to be a true 50 
ohm non-reactive load at the frequency of operation - I use a Caddock 
MP9100-50 1% thick film resistor mounted on a heat sink with very short 
leads to the back side of a BNC connector.  This makes a very good 100 
watt dummy load usable up to 500 MHz.  I rate that resistor as one of 
the best under $10 purchases I have made (the heat sink was free - from 
a discarded computer MPU cooler).


73,
Don W3FPR

Michael Linden wrote:

I'm performing the Bridge Null Adjustment (C55) on my KAT2, but can't
get it below 012. It is clear when adjusting C55 that I _AM_ centered
in the middle of a "dip". However, I can only get the value to go down
to 012. Per the manual, I've checked T1's windings and their continuity
and have checked the continuity and arrangement of the cable wires (J7
and J8) -- I don't see any problems.

Is a minimum value of 012 "good enough", or do I need to look more
closely at the SWR bridge components?

  

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