Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Jeff Wandling]

W7BRS> comments in-line below.



---
73, Jeff  W7BRS
https://blog.w7brs.com



On Monday, January 1st, 2024 at 1:21 PM, Andy Durbin  wrote:


> "Actual Results: The ATU-500 clicks between Bypass and MAN (by "clicks", I 
> mean only what I can infer from the behavior -- it is as if the ATU-500 is 
> either using the memory-based ATU settings of the previously tuned settings 
> and switching between that and what seems like a Bypass mode) -- the clicking 
> is rapid and persistent at the onset of the CW message."
> 
> How does your KAT500 know what frequency to use? Does it have a serial data 
> interface or does it depend only on the internal RF counter?
> 

W7BRS>  AUX cable between K3 to KAT-500 and KAT-500 to KPA-500.  They are in 
serial communication per Elecraft protcol(s), whatever those are.

> What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this anomaly?

W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN.  So I 
leave the KAT-500 in MAN *after* tuning the antenna to 1.1.

> 
> I ask these questions because I doubt the problem has anything to do with SWR 
> thresholds.
> 

W7BRS> Interesting. I am only guessing that the excessive clicking in the 
KAT-500 was the KAT-500 going in/out of BYPASS.  (This isn't the clicking 
associated with the Tune-search for L/C.  It's a different kind of click.   I 
don't know how else to describe it other than a single kind of click as if it 
was a single relay in operation in the KAT-500 -- that same kind of 'click' 
sound that would occur if you switched between MAN and BYPASS on the KAT-500. 
Same sound.  But that's not definitive enough I suppose.  I don't have any 
Serial Log data from the Utility to base that guess.

W7BRS> Thanks for the questions.  I've got a few other replies to sort through 
with other suggestions:

1.  Try dummy load vs. real antenna
2.  Carefully listen if clicks are syncopated with CW (they aren't but I can 
listen again to make sure).
3.  RF/RFI - Not likely except that Serial AUX cable might be picking up some 
RF.. I could attach some ferrite cores around it to rule out.  Otherwise the 
shack is weighted down with ferrite in all the right places -- Everywhere. /hi/

W7BRS> Thanks again for the questions, very good.

> Andy, k3wyc
> 
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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Andy Durbin]

"> How does your KAT500 know what frequency to use? Does it have a serial data 
interface or does it depend only on the internal RF counter?
> 

W7BRS>  AUX cable between K3 to KAT-500 and KAT-500 to KPA-500.  They are in 
serial communication per Elecraft protcol(s), whatever those are.

> What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this anomaly?

W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN.  So I 
leave the KAT-500 in MAN *after* tuning the antenna to 1.1."

Your problem sounded a bit like the conflict between serial data frequency and 
RF count when operating near a "bin" boundary.  However, my only experience 
with that problem is with Kenwood rigs using serial data to provide frequency 
to KAT500.  I have no experience with AUXBus. 

For Kenwood owners one solution was to use the FDT command to desensitize the 
RF counter so serial data frequency always had priority.  The command 
description implies it is equally applicable to AUXBus so may be worth 
experimenting.

"FDT Frequency Counter Distance for Retune
GET format: FDT;
SET/RESPONSE format: FDT nn; where nn is the distance, in kHz, between the 
current ATU frequency and the most recent TX frequency count for the ATU to 
change ATU settings to the new frequency. The value is between 0 (interpreted 
as the default of 10 kHz) thru 65535, which disables ATU tuning based on 
frequency count. This is intended for customers that prefer the KAT500 only 
follow the frequency provided by a serial port command or the K3/K3S/K4 AUXBUS, 
or select a minimum distance between current ATU frequency and a newly counted 
frequency.
FDT was introduced in firmware version 01.99."

Andy, k3wyc

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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[G4GNX]

AFAICR the manual says that if an AUX cable is connected between the KAT500 and 
the radio, the KAT500 will follow any frequency/band change and if a tuning 
solution has already been stored for that frequency/band it will be employed 
before the radio goes into TX. In other words, whilst the radio is still in RX 
mode.

However, elsewhere in the manual it says that when the KAT500 receives RF, it 
will also pickup the nearest tuning solution, which is a fail-safe action in 
case the KAT500 does not receive data from the radio, for any reason.

This is only if the radio is a K3, K3S or K4 and if a KPA500 is in use, RF from 
it is sent to the KAT500 but the AUX cable *must* be connected AFTER the 
KAT500. i.e. K3———KAT500———KPA500.

I make no comment about using the KAT500 with a Kenwood (or other) rig.

73,
Alan - G4GNX
South Coast UK
Elecraft K4D / KPA500 / KAT500 / IC-9700




> On 1 Jan 2024, at 21:56, Andy Durbin  wrote:
> 
> "> How does your KAT500 know what frequency to use? Does it have a serial 
> data interface or does it depend only on the internal RF counter?
>>  
> 
> W7BRS>  AUX cable between K3 to KAT-500 and KAT-500 to KPA-500.  They are in 
> serial communication per Elecraft protcol(s), whatever those are.
> 
>>  What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this anomaly?
> 
> W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN.  So I 
> leave the KAT-500 in MAN *after* tuning the antenna to 1.1."
> 
> Your problem sounded a bit like the conflict between serial data frequency 
> and RF count when operating near a "bin" boundary.  However, my only 
> experience with that problem is with Kenwood rigs using serial data to 
> provide frequency to KAT500.  I have no experience with AUXBus. 
> 
> For Kenwood owners one solution was to use the FDT command to desensitize the 
> RF counter so serial data frequency always had priority.  The command 
> description implies it is equally applicable to AUXBus so may be worth 
> experimenting.
> 
> "FDT Frequency Counter Distance for Retune
> GET format: FDT;
> SET/RESPONSE format: FDT nn; where nn is the distance, in kHz, between the 
> current ATU frequency and the most recent TX frequency count for the ATU to 
> change ATU settings to the new frequency. The value is between 0 (interpreted 
> as the default of 10 kHz) thru 65535, which disables ATU tuning based on 
> frequency count. This is intended for customers that prefer the KAT500 only 
> follow the frequency provided by a serial port command or the K3/K3S/K4 
> AUXBUS, or select a minimum distance between current ATU frequency and a 
> newly counted frequency.
> FDT was introduced in firmware version 01.99."
> 
> Andy, k3wyc

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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Jeff Wandling]

Thanks.  That's good detail.  I'll recheck the manual once more.  I made a 
common mistake of assuming too much and not reading enough.   I have tremendous 
respect and faith in the engineering put into the system of the Elecraft line.. 
 That's a  long way of saying, It works brilliantly.

I just want to avoid a mistake in where the ATU-500 and KPA-500 are trying to 
resolve a tune whilst the CW spews forth.

This comment and the prior comment about the Kenwood aspect (and related 
command-set mentioned) are interesting.   Thanks.

Aside from all that -- when folks here use the "SWR Thresholds" and use the 
K3+KAT+KPA chain via Aux Serial data sharing -- what do you use for the three 
metrics in SWR Thresholds?

There's a KPA Inhibit SWR,   Re-tune SWR and Bypass SWR value.  The recommended 
values in the manuals seem frightfully high for my nerves to handle.

Any advice on *that* would be welcomed.

HNY, Thanks.

---
73, Jeff  W7BRS
https://blog.w7brs.com



On Monday, January 1st, 2024 at 4:37 PM, G4GNX  wrote:


> AFAICR the manual says that if an AUX cable is connected between the KAT500 
> and the radio, the KAT500 will follow any frequency/band change and if a 
> tuning solution has already been stored for that frequency/band it will be 
> employed before the radio goes into TX. In other words, whilst the radio is 
> still in RX mode.
> 
> However, elsewhere in the manual it says that when the KAT500 receives RF, it 
> will also pickup the nearest tuning solution, which is a fail-safe action in 
> case the KAT500 does not receive data from the radio, for any reason.
> 
> This is only if the radio is a K3, K3S or K4 and if a KPA500 is in use, RF 
> from it is sent to the KAT500 but the AUX cable must be connected AFTER the 
> KAT500. i.e. K3———KAT500———KPA500.
> 
> I make no comment about using the KAT500 with a Kenwood (or other) rig.
> 
> 73,
> Alan - G4GNX
> South Coast UK
> Elecraft K4D / KPA500 / KAT500 / IC-9700
> 
> 
> 
> > On 1 Jan 2024, at 21:56, Andy Durbin a.dur...@msn.com wrote:
> > 
> > "> How does your KAT500 know what frequency to use? Does it have a serial 
> > data interface or does it depend only on the internal RF counter?
> > 
> > W7BRS> AUX cable between K3 to KAT-500 and KAT-500 to KPA-500. They are in 
> > serial communication per Elecraft protcol(s), whatever those are.
> > 
> > > What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this 
> > > anomaly?
> > 
> > W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN. So 
> > I leave the KAT-500 in MAN after tuning the antenna to 1.1."
> > 
> > Your problem sounded a bit like the conflict between serial data frequency 
> > and RF count when operating near a "bin" boundary. However, my only 
> > experience with that problem is with Kenwood rigs using serial data to 
> > provide frequency to KAT500. I have no experience with AUXBus.
> > 
> > For Kenwood owners one solution was to use the FDT command to desensitize 
> > the RF counter so serial data frequency always had priority. The command 
> > description implies it is equally applicable to AUXBus so may be worth 
> > experimenting.
> > 
> > "FDT Frequency Counter Distance for Retune
> > GET format: FDT;
> > SET/RESPONSE format: FDT nn; where nn is the distance, in kHz, between the 
> > current ATU frequency and the most recent TX frequency count for the ATU to 
> > change ATU settings to the new frequency. The value is between 0 
> > (interpreted as the default of 10 kHz) thru 65535, which disables ATU 
> > tuning based on frequency count. This is intended for customers that prefer 
> > the KAT500 only follow the frequency provided by a serial port command or 
> > the K3/K3S/K4 AUXBUS, or select a minimum distance between current ATU 
> > frequency and a newly counted frequency.
> > FDT was introduced in firmware version 01.99."
> > 
> > Andy, k3wyc
> 
> 
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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Jack Brindle via Elecraft]

KPA inhibit SWR? The KPA500 uses Reflected Power for all of its protections 
except for one item - if the SWR is above 18:1, it will throw an immediate 
fault.
There is no adjustment for these thresholds. As far as the Auxbus, the KPA does 
not listen but only talks on it, conveying band, mode and power on/off status.
The KPA gets its band data from the K3 using the BAND lines. The KPA always 
does a frequency count of the input signal, and will change bands if the
count indicates a band other than what was expected. And yes, we have seen 
instances where parasitics from a transceiver triggered the band change.
It turns out they were much higher in amplitude than the fundamental frequency. 
I don’t remember the  transceiver manufacturer, but it was not an Elecraft.

The KAT500 has adjustments for SWR for tuning requirement. I don’t recall any 
others, but there may be. The manual should state them. The KAT does
listen to the Auxbus, getting frequency info. As you know, if the calculated 
SWR is above the threshold, the KAT will disable the PTT signal to the KPA, and 
if
in the AUTO mode, it will initiate a tune. Because of timing differences with 
measuring forward and reflected power, we do not recommend leaving the KAT
in AUTO mode, especially for SSB transmissions.

One other thing to consider is that the KAT has an internal bypass, which 
leaves the KAT Ls & Cs in-line, which is separate from the front-panel BYPASS 
mode,
which completely bypasses the Ls and Cs. Also, if the KAT sees too much power 
at its input when it starts a tune, it will add a resistive pad to lower the 
power
it sees so that it does not hot-switch the relays.

I hope this helps explain what you are seeing. I wonder if you have the two 
thresholds spaced too closely. 1.4:1 and 1.6:1 are awfully close for 
calculations.

Also, I would be really interested in hearing more about the loop antenna you 
are driving, along with the coax feed, and all connectors. We see an amazingly 
large
amount of problems in the KAT & KPA due to issues that are actually in the 
antenna system.

73,
Jack, W6FB



> On Jan 1, 2024, at 6:46 PM, Jeff Wandling  wrote:
> 
> Thanks.  That's good detail.  I'll recheck the manual once more.  I made a 
> common mistake of assuming too much and not reading enough.   I have 
> tremendous respect and faith in the engineering put into the system of the 
> Elecraft line..  That's a  long way of saying, It works brilliantly.
> 
> I just want to avoid a mistake in where the ATU-500 and KPA-500 are trying to 
> resolve a tune whilst the CW spews forth.
> 
> This comment and the prior comment about the Kenwood aspect (and related 
> command-set mentioned) are interesting.   Thanks.
> 
> Aside from all that -- when folks here use the "SWR Thresholds" and use the 
> K3+KAT+KPA chain via Aux Serial data sharing -- what do you use for the three 
> metrics in SWR Thresholds?
> 
> There's a KPA Inhibit SWR,   Re-tune SWR and Bypass SWR value.  The 
> recommended values in the manuals seem frightfully high for my nerves to 
> handle.
> 
> Any advice on *that* would be welcomed.
> 
> HNY, Thanks.
> 
> ---
> 73, Jeff  W7BRS
> https://blog.w7brs.com 
> 
> 
> 
> On Monday, January 1st, 2024 at 4:37 PM, G4GNX  > wrote:
> 
> 
>> AFAICR the manual says that if an AUX cable is connected between the KAT500 
>> and the radio, the KAT500 will follow any frequency/band change and if a 
>> tuning solution has already been stored for that frequency/band it will be 
>> employed before the radio goes into TX. In other words, whilst the radio is 
>> still in RX mode.
>> 
>> However, elsewhere in the manual it says that when the KAT500 receives RF, 
>> it will also pickup the nearest tuning solution, which is a fail-safe action 
>> in case the KAT500 does not receive data from the radio, for any reason.
>> 
>> This is only if the radio is a K3, K3S or K4 and if a KPA500 is in use, RF 
>> from it is sent to the KAT500 but the AUX cable must be connected AFTER the 
>> KAT500. i.e. K3———KAT500———KPA500.
>> 
>> I make no comment about using the KAT500 with a Kenwood (or other) rig.
>> 
>> 73,
>> Alan - G4GNX
>> South Coast UK
>> Elecraft K4D / KPA500 / KAT500 / IC-9700
>> 
>> 
>> 
>>> On 1 Jan 2024, at 21:56, Andy Durbin a.dur...@msn.com wrote:
>>> 
>>> "> How does your KAT500 know what frequency to use? Does it have a serial 
>>> data interface or does it depend only on the internal RF counter?
>>> 
>>> W7BRS> AUX cable between K3 to KAT-500 and KAT-500 to KPA-500. They are in 
>>> serial communication per Elecraft protcol(s), whatever those are.
>>> 
 What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this 
 anomaly?
>>> 
>>> W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN. So 
>>> I leave the KAT-500 in MAN after tuning the antenna to 1.1."
>>> 
>>> Your problem sounded a bit like the conflict between serial data frequency 
>>> and RF count when operating 

Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Andy Durbin]

"AFAICR the manual says that if an AUX cable is connected between the KAT500 
and the radio, the KAT500 will follow any frequency/band change and if a tuning 
solution has already been stored for that frequency/band it will be employed 
before the radio goes into TX. In other words, whilst the radio is still in RX 
mode.

However, elsewhere in the manual it says that when the KAT500 receives RF, it 
will also pickup the nearest tuning solution, which is a fail-safe action in 
case the KAT500 does not receive data from the radio, for any reason."

Any KAT500 can have knowledge of the TX frequency either by using the RF 
counter or by receiving advance notice of theTX frequency by serial data or the 
Elecraft proprietary AuxBus.  The issue is what happens when both data sets are 
present and they conflict.

Both AUXBus and serial port data can provide TX frequency to 1 kHz resolution.  
The RF counter only has 8 kHz resolution.  If the RF count falls outside the 
bin tuned by serial port data or AUXBus then the tuning solution may change 
when TX starts.

Before formware 1.99 there were various commands available that were intended 
to tailor the priority given to RF count but they did not work as documented.  
These commands were replaced by FDT command which is what allows the user to 
configure the frequency difference for which RF count will override serial / 
AUXbus frequency.

Unlike the earlier "tailoring" commands, FDT does work as documented.

Andy, k3wyc


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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[G4GNX]

Jeff,

One thing I forgot. The KAT500 should only be in AUTO mode when you’re actually 
training it. i.e. You tune the radio to a frequency, then TX (in TUNE mode) and 
wait for the KAT500 to stop clicking. ISTR that when a solution is found, the 
KAT500 TUNE light goes off and the solution is stored automatically. Then you 
move to the next segment in the band. There’s a chart in the manual which gives 
recommended segments for each tuning solution per band. If you’re not happy 
with the 1st solution, you can force a finer tune by pressing the TUNE button 
immediately after it stops tuning the 1st time.

For normal operation the KAT500 should always be in MANUAL mode. If the antenna 
system changes (rain etc.,) you can force a retune at any time and it will be 
stored.

If you can get hold of a copy of Fred Cady’s book on the KAT500/KPA500, you’ll 
find it useful reading and IMO it explains things slightly better than the 
standard manuals.

73,
Alan - G4GNX
South Coast UK
Elecraft K4D / KPA500 / KAT500 / IC-9700




> On 2 Jan 2024, at 00:46, Jeff Wandling  wrote:
> 
> Thanks.  That's good detail.  I'll recheck the manual once more.  I made a 
> common mistake of assuming too much and not reading enough.   I have 
> tremendous respect and faith in the engineering put into the system of the 
> Elecraft line..  That's a  long way of saying, It works brilliantly.
> 
> I just want to avoid a mistake in where the ATU-500 and KPA-500 are trying to 
> resolve a tune whilst the CW spews forth.
> 
> This comment and the prior comment about the Kenwood aspect (and related 
> command-set mentioned) are interesting.   Thanks.
> 
> Aside from all that -- when folks here use the "SWR Thresholds" and use the 
> K3+KAT+KPA chain via Aux Serial data sharing -- what do you use for the three 
> metrics in SWR Thresholds?
> 
> There's a KPA Inhibit SWR,   Re-tune SWR and Bypass SWR value.  The 
> recommended values in the manuals seem frightfully high for my nerves to 
> handle.
> 
> Any advice on *that* would be welcomed.
> 
> HNY, Thanks.
> 
> ---
> 73, Jeff  W7BRS
> https://blog.w7brs.com
> 
> 
> 
> On Monday, January 1st, 2024 at 4:37 PM, G4GNX  wrote:
> 
> 
>> AFAICR the manual says that if an AUX cable is connected between the KAT500 
>> and the radio, the KAT500 will follow any frequency/band change and if a 
>> tuning solution has already been stored for that frequency/band it will be 
>> employed before the radio goes into TX. In other words, whilst the radio is 
>> still in RX mode.
>> 
>> However, elsewhere in the manual it says that when the KAT500 receives RF, 
>> it will also pickup the nearest tuning solution, which is a fail-safe action 
>> in case the KAT500 does not receive data from the radio, for any reason.
>> 
>> This is only if the radio is a K3, K3S or K4 and if a KPA500 is in use, RF 
>> from it is sent to the KAT500 but the AUX cable must be connected AFTER the 
>> KAT500. i.e. K3———KAT500———KPA500.
>> 
>> I make no comment about using the KAT500 with a Kenwood (or other) rig.
>> 
>> 73,
>> Alan - G4GNX
>> South Coast UK
>> Elecraft K4D / KPA500 / KAT500 / IC-9700

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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Andy Durbin]

"One thing I forgot. The KAT500 should only be in AUTO mode when you’re 
actually training it."

Training a KAT500 does not require it to be in AUTO mode.  I NEVER put my 
KAT500 in AUTO mode and I can auto train a complete band with one button push.

Andy, k3wyc
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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Mike Dodd]

On 1/1/2024 9:33 PM, Andy Durbin wrote:

...I can auto train a complete band with one button push.


What button is that, Andy? I set up a spreadsheet that shows the 
frequency steps for the bands, and programmed a K-Pod button to bump the 
VFO by the correct delta, but I still need to tap the TUNE switch on the 
KAT500 and the TUNE switch on the K4.


Do you have a K-Pod button programmed to do all this?

73, mike N4CF


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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Jeff Wandling]

This reply is going back in the thread, on purpose because I've settled the 
matter.  The follow on discussion in the other thread was informative (thanks) 
and I'll store it in a note for the station.

TL;DR; Situation is resolved.  Bad RF due to crap elbow connector and lack of 
diligence in ferrite application on AUX serial cabling.

--
Gory Details:

Some background that I apologize for not mentioning (and wasting your time - 
very sorry).  But, I didn't know at the time of the original question post.

When I was testing *after* the post, I went to the KPA and flipped the display 
to show TEMP.   So when I repeated the experiment (even into a dummy load), I 
heard the clicks as before, but when I glanced at the LCD panel of the KPA I 
noticed that the Frequency was bouncing around.  (14 Mhz then 18Mhz then back 
to 14Mhz and then show the TEMP again). I thought, "why on earth is the KPA 
trying to use a different frequency??"

That triggered some evaluation of an earlier email (name withheld) that 
mentioned RF in the shack.  I dug through the parts bin and got a handful of 
snap-on ferrite and loaded up the AUX Cables on the ends..  Tons of ferrite.  
OK so then I re-ran the test.  Same result but slightly better. Not as much 
relay chatter.

Then I began to wonder about the RF again.  I decided to move some equipment.  
I moved the KPA from the top of the KAT and placed it nearby but not as it was 
before.  Re-routed the coax and so on and re-tested.  But this time not as 
pervasive.  Some relay chatter,  but less clicking (and less band-switching in 
the KPA). OK, so we're getting somewhere...

Then I took a real good look at the coax.  Sure enough those Amphenol elbow 
connectors were not what I thought they were.   Upon closer inspection I 
realized they were (let us just say) not what I wanted.

I swapped them out and lo and behold the problem was gone.   No amount of CW 
into the Dummy Load would trigger the click (ie., the "band switch" clicking).  
It was the band-switch relay that was clicking after all. Not the Bypass to MAN 
and vice versa...

I was too proud to notice that I had a couple of connectors that were not the 
prime quality.  And too proud to realize I hadn't really applied as much 
ferrite where it needed to be.  

I am really sorry to spin up so many great minds to think about this.   

Lesson learned.  
Really make sure RF(I) is eliminated.  
Really.  
Eliminated. 

Now, to whom should I send a complementary coffee gift card with the essential 
fix...  Thanks very much.

I return you now to the list for more important issues.

Thanks.

---
73, Jeff  W7BRS
https://blog.w7brs.com



On Monday, January 1st, 2024 at 1:31 PM, Jeff Wandling  wrote:


> W7BRS> comments in-line below.
> 
> 
> 
> 
> ---
> 73, Jeff W7BRS
> https://blog.w7brs.com
> 
> 
> 
> On Monday, January 1st, 2024 at 1:21 PM, Andy Durbin a.dur...@msn.com wrote:
> 
> 
> 
> > "Actual Results: The ATU-500 clicks between Bypass and MAN (by "clicks", I 
> > mean only what I can infer from the behavior -- it is as if the ATU-500 is 
> > either using the memory-based ATU settings of the previously tuned settings 
> > and switching between that and what seems like a Bypass mode) -- the 
> > clicking is rapid and persistent at the onset of the CW message."
> > 
> > How does your KAT500 know what frequency to use? Does it have a serial data 
> > interface or does it depend only on the internal RF counter?
> 
> 
> W7BRS> AUX cable between K3 to KAT-500 and KAT-500 to KPA-500. They are in 
> serial communication per Elecraft protcol(s), whatever those are.
> 
> > What KAT500 mode (AUTO, MAN, BYP) is selected when you observe this anomaly?
> 
> 
> W7BRS> Per manual for KAT-500/KPA-500 the stated "nominal" mode is MAN. So I 
> leave the KAT-500 in MAN after tuning the antenna to 1.1.
> 
> > I ask these questions because I doubt the problem has anything to do with 
> > SWR thresholds.
> 
> 
> W7BRS> Interesting. I am only guessing that the excessive clicking in the 
> KAT-500 was the KAT-500 going in/out of BYPASS. (This isn't the clicking 
> associated with the Tune-search for L/C. It's a different kind of click. I 
> don't know how else to describe it other than a single kind of click as if it 
> was a single relay in operation in the KAT-500 -- that same kind of 'click' 
> sound that would occur if you switched between MAN and BYPASS on the KAT-500. 
> Same sound. But that's not definitive enough I suppose. I don't have any 
> Serial Log data from the Utility to base that guess.
> 
> 
> W7BRS> Thanks for the questions. I've got a few other replies to sort through 
> with other suggestions:
> 
> 
> 1. Try dummy load vs. real antenna
> 2. Carefully listen if clicks are syncopated with CW (they aren't but I can 
> listen again to make sure).
> 3. RF/RFI - Not likely except that Serial AUX cable might be picking up some 
> RF.. I could attach some ferrite cores around it to rule out. Otherwise the 
> shack is weighted down with fer

Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Mike Dodd]

On 1/1/2024 11:15 PM, Andy Durbin wrote:

"Do you have a K-Pod button programmed to do all this?"

No, it's code in an Arduino Mega 256 than sequences a couple of state 
machines


Very interesting. I'm sure I could program something similar, but given 
how infrequently I need to re-train my KAT500, I think I'll stick with 
my frequency-step spreadsheet and a couple of K-Pod macros.


73, Mike N4CF


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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Jim Brown]

On 1/1/2024 8:33 PM, Jeff Wandling wrote:

TL;DR; Situation is resolved.  Bad RF due to crap elbow connector and
lack of diligence in ferrite application on AUX serial cabling.


Thanks for posting. Two points. First, NEVER use JUNK connectors, 
defined as anything that isn't stamped Amphenol, or with MIL-spec 
numbers. All that stuff sold at ham flea markets is designed for CBers.


When I got back on the air in 2003 after 25 years, I didn't realize that 
all this junk had come on the scene, so stocked up with all sorts of 
adapters, Tees, elbows, barrels. Over the next five years, they caused 
me all sorts of problems that were difficult to find. Those elbows have 
nothing but a tiny spring inside, that melts with power. I've had Tees 
and adapters fall apart.


Second, needing ferrites on interconnect cables is often the result of 
failure to do proper bonding in the shack, and/or omitting a serious 
transmitting choke at the feedpoint of every antenna, and/or omitting 
radials for end fed antennas that need them.


Guidelines for transmitting chokes and for grounding and bonding are on 
my website, k9yc.com/publish.htm


73, Jim K9YC
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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[G4GNX]

I did not say that you can’t train in manual mode. I said AUTO should only be 
used for training - not for normal operation.

I really hope that your one button push takes account of other users on the 
band when you’re training. Presumably it has some very sophisticated detection 
that can tell if a frequency is in use?

73,
Alan - G4GNX
South Coast UK
Elecraft K4D / KPA500 / KAT500 / IC-9700


>> On 2 Jan 2024, at 02:33, Andy Durbin  wrote:
>> 
>> "One thing I forgot. The KAT500 should only be in AUTO mode when you’re 
>> actually training it."
>> 
>> Training a KAT500 does not require it to be in AUTO mode.  I NEVER put my 
>> KAT500 in AUTO mode and I can auto train a complete band with one button 
>> push.
>> 
>> Andy, k3wyc
>> 
> 

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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[G4GNX]

Why battle against the inevitable, rather than use a band that’s more 
appropriate for the time of day? Unless of course, all bands are dead - then 
we’re all screwed. 😀

73,
Alan - G4GNX
South Coast UK
Elecraft K4D / KPA500 / KAT500 / IC-9700




> On 2 Jan 2024, at 15:12, Andy Durbin  wrote:
> 
> 
> "Presumably it has some very sophisticated detection that can tell if a 
> frequency is in use?"
> 
> My auto trainer function is only used on 160 m and 80 m and only during the 
> day when I expect the bands to be dead and as confirmed by the panadapter.   
> It doesn't need a detection system any more sophisticated than a mark one 
> eyeball.
> 
> My problem on 160 and 80 is not that I will cause QRM.  My problem is 
> radiating a signal strong enough to make a QSO.
> 
> Andy, k3wyc

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Re: [Elecraft] KAT-500 + KPA-500 / SWR Thresholds

[Wes]

If it was easy, then anyone could do it.

On 1/2/2024 8:52 AM, G4GNX wrote:

Why battle against the inevitable, rather than use a band that’s more 
appropriate for the time of day? Unless of course, all bands are dead - then 
we’re all screwed. 😀

73,
Alan - G4GNX
South Coast UK
Elecraft K4D / KPA500 / KAT500 / IC-9700



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