Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Wes]

In an earlier message on a different, but related thread: 
http://elecraft.365791.n2.nabble.com/K3-SWR-Numerical-Indication-td7643839.html


I wrote:

"I would be surprised if two garden variety instruments, even placed at the same
point, would agree. The directional bridges/couplers in most "(V)SWR" meters
that hams routinely use externally or which are built into our radios are not
precision instruments.  There are a number of error sources in reflection
measurements; source match, diode non-linearity, coupler tracking errors and
often the most significant, directivity error.

In an ideal coupler, (i.e signal separation device) one port measures the
forward (incident signal) and another measures the reverse (reflected) signal
and there is no coupling between ports in the unwanted direction(s).  In other
words there is no signal at the reverse port due to the forward signal.  In a
real world coupler there is some leakage signal appearing at the reverse port
due to the forward signal, absent any reflected signal.  The "goodness" of a
directional coupler in this instance is called "directivity" and the error
signal is directivity error. Directivity is usually specified in dB.  Really
good couplers might have directivities in the 40 dB neighborhood. Really really
good directional bridges can be 50 dB, but so-so units might be 25-30 dB.  Not
ready for prime time units are lower than this.

Now I have no way of knowing what the directivities are of the couplers built
into K3s, KPA500s, KAT500s, etc. but considering that they have to work over
about 5 octaves, I'm going out on a limb and saying that 25 to 30 dB is a fair
estimate.  If I'm wrong, I'm sure I'll hear about it.  For sake of discussion
I'm going to use 26.5 dB.  What this means is that if I terminate the output
spigot of one of these radios with a perfect 50+j0 load, I'm going to measure a
leakage signal (directivity error) that is 26.5 dB below the incident value.
I'll introduce the concept of return loss here.

We hams usually speak in terms of SWR.  SWR = (1 + p) / (1 - p) where p is the
reflection coefficient. Here the p = the voltage measured at the reflected port
and the constant 1 represents the incident signal.  In reality both of these
quantities are complex numbers, they have both magnitude and phase but SWR
measurements are scalar, we throw away the phase (since it's difficult to
measure) and just use the magnitude. (In fact the symbol "p", which is really
the Greek letter rho, indicates the magnitude of the reflection coefficient in
normal usage)  We can also express this ratio as return loss, which is -20 *
log10(p).  So return loss, SWR and reflection coefficient are just different
ways to express the same thing; the ratio of incident to reflected signal.

Let's return to our example; the coupler with 26.5 dB directivity, which
indicates a return loss (RL) of 26.5 dB even with a perfect termination.  Doing
the math and converting RL = 26.5 dB to SWR we get 1.1:1.  Our perfect load
measures 1.1:1 with our imperfect instrument.  And this assumes that there are
no other errors, which there always are. But it gets worse.

Let's say that the load we want to measure really is 1.1:1.  We now have two
(apparent) reflections, 1) the real one and 2) the directivity error and they
both have the same magnitude.  In our simple detector, they sum together.  Now I
said earlier that we don't measure phase, only magnitude, but just because we
don't, or can't measure the relative phases doesn't mean they aren't there. We
will examine two cases to determine the limits of error.  Case 1) both
reflections are in phase, they add up to p + p or 2p, RL = 20.5 and SWR
~1.21:1.  Case 2) they are exactly out of phase, they sum to zero.  p = 0, RL is
infinite and SWR = 1:1.  The possible RL error is then -6 to +infinity dB!

In other words, an actual SWR of 1.1:1 can be measured anywhere between 1.0:1
and 1.2:1.  Is it any wonder that we often read about concerns that one device
measures one thing, while another located at the same, or close location
measures something different.  Of course all of this is predicated on a
directional coupler with 26.5 dB directivity and no other error sources.  It's
entirely possible that the Elecraft couplers are better than this.  They are
certainly no better than 40 dB since the internal reference resistors are 51
instead of 50 ohm.  Plus the "Tandem Match" configuration is in itself not a
great match to the transmitter output.(1)  Furthermore, the coupler, at least in
a K3 is driven by a LPF, which isn't a great 50 ohm source. Plus the coupler
output port isn't connected directly to the coax connector. and so on and so
forth (2).  All of this creates "uncertainty."

In a metrology lab heroic efforts are made to reduce uncertainty but do we, or
should we, really care in this situation?  In my opinion, no, but everyone is
free to differ.

Wes  N7WS

(1)  See "An HF In-Line Return Loss And Power Meter" by Paul Kiciak, N2PK.

Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Lou W0FK]

What are the error codes when you hard fault? Check them and see if there’s
any consistency.

 I sometimes get hard faults when I’ve moved my rf deck, simply because the
PowerPoles on the 12v line from the power supply have moved a bit and aren’t
making a good connection. I usually see a 50v warning pop up that alerts me
to the issue.  Have you made sure that 12v line is secured?

I also concur that 90 watts Drive into the amp is way too much. That
suggests the amp is the culprit. The innovantenna balun is pretty robust.
But if you suspect it, bypass it and test a direct line with pigtailed ends
directly into the loop.

73, Lou W0FK





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Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Mark Goldberg]

I haven't seen a discussion of your grounding system or feedline length. 6M
can be picky.  What does your ground system look like? Do you have any
common mode chokes on the feedline? Have you tried adding or subtracting
2-3 feet from the feedline? If it is exactly a multiple of 1/2 wave or 1/4
wave changing the feedline length will move it away from that. Have you
tried adding a counterpoise in the shack? That's not the ultimate solution
but if it improves things it will tell you something. Can you point an IR
thermometer at tuner / balun inductors to see if they are getting hot? Just
throwing out ideas.

73,

Mark
W7MLG


On Sun, May 31, 2020 at 9:08 PM Peter Dougherty  wrote:

> New coax and old coax behaved identically. HOWEVER, running into about 80
> feet of old RG-213 and into the Cantenna dummy load and it doesn't fault.
> This is the only condition on 6m where there is no fault. Brand new coax,
> old coax, brand new antenna, old antenna, with balun, without balun. Always
> faults except when feeding the pure resistive dummy load. If there's any
> reactance it trips or gives false SWR info.
>
> I would also add, why would a 2:1 SWR trip out the amp at 25 or 30 Watts
> of drive? On the regular HF bands I can use the internal tuner to take out
> a 2.5 or 3:1 SWR and it still sends 1400-1450 Watts up the pipe..
>
>  - pjd
>
>
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Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Vic Rosenthal]

Are you using the same output connector on the KPA1500 for the dummy load and 
the antenna? 
Perhaps the problem is in one of the SO239s or in the KPA’s switching circuit?

Victor 4X6GP 

> On 1 Jun 2020, at 4:30, Peter Dougherty  wrote:
> 
> Many here suggested that it was most likely a feedline issue, and I figured
> this was indeed a distinct possibility. 
> 
> So this afternoon I replaced the feedline. I now have about 80 feet of brand
> new LMR-400, new 83-SP1 connectors (and an Amphenol adaptor at the balun
> since I don't have any type-N connectors here). The AA-230 ZOOM analyzer
> shows about 1.2:1 at 50.313, with resonance just below the band. I'll fix
> that tomorrow, but 1.2 or 1.3:1 should be nothing to the KPA. 
> 
> The TDR screen looks very clean, just a tiny bump where the feedline goes
> through the (new) bulkhead connector to get into the house. See:
> https://www.dropbox.com/s/izcwvece7nt5f42/2020-05-31%2019.32.44.jpg?dl=0
> 
> The SWR chart between 50.000 and 50.500:
> https://www.dropbox.com/s/y2xh4l1lihy2ujr/2020-05-31%2021.23.29.jpg?dl=0
> 
> Again, I know the antenna is resonant a bit low, but this should NOT be a
> factor. So here's what's now going on.
> 
> 1) Into a Cantenna dummy load, with 25W of drive from the M3s, the KPA-1500
> is delivering 1075W and showing 1.4:1. No problem delivering power and no
> faults.
> 
> 2) With input power increased, 35W of K3s drive gives 1375W at 1.5 into the
> Cantenna. Again, no problem delivering power to the purely resistive load.
> Why a 1.5:1, I don't know, but fine, whatever. I can TX for 15-20 second
> periods without issue.
> 
> 3) When I switch over to the live antenna, with25 Watts of drive from the
> K3s into the actual antenna and the amp faults out instantly in bypass. When
> the amplifier is in bypass and the tuner is in bypass, and when the K3s is
> delivering about 90W in FT8 mode, the front panel on the KPA-1500 says the
> SWR is 1.9:1. When I press the TUNE button on the radio, it's showing an SWR
> of 1.4:1. 
> 
> 4) Amp in bypass, tuner inline, press TUNE button on the K3s and the front
> panel of the KPA-1500 is showing a perfect 1.0:1 match. It SHOULD work fine
> like this, right?
> 
> 5) Pressing ONLY the OPER/STBY button to put the amp in operate (KPA tuner
> in and untouched since step 4), the amp SOMETIMES delivers power, sometimes
> faults out, shows an SWR of 1.7:1. Pressing the OPER/STBY button again to
> use only exciter power, and touching NOTHING ELSE, it's back to 1.1:1 with
> 90W of K3s drive.
> 
> 6) There is basically no rhyme or reason why this is happening and it's
> *somewhat* repeatable. The incredibly frustrating part is if I see a needed
> station come up, I'll flick the amp's tuner in line and it says it's tuned.
> Once WSJT-X keys the radio, 90 out of 100 times the amp will hard-fault. If
> it doesn't fault on the first transmission, it absolutely WILL on the second
> transmission. 
> 
> So I'm now at a complete loss to understand what's going on here. Amp is
> fine into a resistive load. Brand-new antenna, brand new LMR-400 feedline,
> brand new connectors, the KPA-1500 is faulting out the same as it did on the
> 10+ year old 6M5 with a patchwork of feedlines. I can't see how this is
> anything but a problem in the KPA-1500 (S/N 0398).
> 
> - pjd
> 
> -Original Message-
> From: elecraft-boun...@mailman.qth.net  On
> Behalf Of Jim Brown
> Sent: Sunday, May 31, 2020 8:22 PM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues
> 
>> On 5/31/2020 9:54 AM, Jim Miller wrote:
>> Have you vetted your feedline at 1500w? Many times something might be 
>> good at low power and fail at 1500.
> 
> This is good advice. Guys who do lots of portable setup say to always check
> the coax first, which mostly means check for a connector that's bad or badly
> installed.
> 
> In general, if it doesn't say Amphenol or isn't stamped with a MIL spec
> number, it's very likely to be poor quality. This includes barrels,
> adapters, etc.  Also make sure that every connector is" wrench tight."
> 
> The advice to run it straight to a dummy load is right on -- if you have one
> big enough. :)
> 
> 73, Jim K9YC
> __
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[Elecraft] Elecraft CW Net Report

[kevinr]

Good Evening,

   Twenty meters was loud again with many signals.  There was QSB and 
nowhere to start a net.  So I punched down my rising bread dough and 
formed a loaf.  There was time enough for it to rise and bake before the 
second net.  However, the smell of it was holding my attention.  Then 
Marv regained it from Washington with a weak signal.  Dale and Brian 
were about the same strength with the same amount of QSB.  Their weather 
reports were different.  While we had all had clouds and rain, Dale had 
a downpour.  Now his new plants are well settled for the summer.  It is 
time for another warm spell.  Then my sourdough starter can grow more 
active.  A cool house keeps the loaves more dense but the flavor is 
incredible.  Time for me to actively fill my truck with firewood to burn 
off the extra calories.  One thing I have noticed with the slower life 
style of the last few months is I spend more time cooking.  The stack of 
dishes piling up has a governing effect.



  On 7047.5 kHz at z:

KG7V - Marv - WA

K6PJV - Dale - CA

K0DTJ - Brian - CA


Around noon I saw a new bird perched behind the house.  I think it was a 
female Black-throated gray warbler.  I need another sighting to confirm 
things though she may have just been passing through.  The forest has 
been filling with new bird calls.  This may have been one of them.


   Until next week stay well 73,

  Kevin.  KD5ONS

-


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Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Peter Dougherty]

New coax and old coax behaved identically. HOWEVER, running into about 80 feet 
of old RG-213 and into the Cantenna dummy load and it doesn't fault. This is 
the only condition on 6m where there is no fault. Brand new coax, old coax, 
brand new antenna, old antenna, with balun, without balun. Always faults except 
when feeding the pure resistive dummy load. If there's any reactance it trips 
or gives false SWR info.

I would also add, why would a 2:1 SWR trip out the amp at 25 or 30 Watts of 
drive? On the regular HF bands I can use the internal tuner to take out a 2.5 
or 3:1 SWR and it still sends 1400-1450 Watts up the pipe..

 - pjd

-Original Message-
From: Adrian  
Sent: Sunday, May 31, 2020 11:05 PM
To: Peter Dougherty ; 'Paul Baldock' ; 
elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR 
issues)

To remove any doubt, a 1.5kw or close dummy load at the end of the coax to 
replace antenna, would confirm the amp issue.

On 1/6/20 12:27 pm, Peter Dougherty wrote:
> Paul, please re-read what I wrote. The 90W figure is with the amp IN 
> STANDBY! I wouldn't dream of putting more than about 35W into the KPA-1500.
> I generally like to run about 1200W on 6m, but even if I turn my K3s 
> drive down to 20 Watts, it will STILL hard-fault regularly. NO AMOUNT 
> OF DRIVE from the K3s will stop these problems. If the amp is set to 
> deliver power it's going to fault on 6m, regardless of what the ATU is 
> set for (bypass or inline), and the KPA will miss-read the SWR of the antenna 
> system.
>
> The resistance figure is 50.8 Ohms, and the reactance is -11 according 
> to the AA-230. The only difference between "works reliably" and 
> "faults out all the time" is one is a resistive-only load, the other 
> has a reactive component.
>
>   - pjd
>
> -
>

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Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Adrian]

To remove any doubt, a 1.5kw or close dummy load at the end of the coax 
to replace antenna, would confirm the amp issue.


On 1/6/20 12:27 pm, Peter Dougherty wrote:

Paul, please re-read what I wrote. The 90W figure is with the amp IN
STANDBY! I wouldn't dream of putting more than about 35W into the KPA-1500.
I generally like to run about 1200W on 6m, but even if I turn my K3s drive
down to 20 Watts, it will STILL hard-fault regularly. NO AMOUNT OF DRIVE
from the K3s will stop these problems. If the amp is set to deliver power
it's going to fault on 6m, regardless of what the ATU is set for (bypass or
inline), and the KPA will miss-read the SWR of the antenna system.

The resistance figure is 50.8 Ohms, and the reactance is -11 according to
the AA-230. The only difference between "works reliably" and "faults out all
the time" is one is a resistive-only load, the other has a reactive
component.

  - pjd

-


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Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Peter Dougherty]

Paul, please re-read what I wrote. The 90W figure is with the amp IN
STANDBY! I wouldn't dream of putting more than about 35W into the KPA-1500.
I generally like to run about 1200W on 6m, but even if I turn my K3s drive
down to 20 Watts, it will STILL hard-fault regularly. NO AMOUNT OF DRIVE
from the K3s will stop these problems. If the amp is set to deliver power
it's going to fault on 6m, regardless of what the ATU is set for (bypass or
inline), and the KPA will miss-read the SWR of the antenna system. 

The resistance figure is 50.8 Ohms, and the reactance is -11 according to
the AA-230. The only difference between "works reliably" and "faults out all
the time" is one is a resistive-only load, the other has a reactive
component.

 - pjd

-Original Message-
From: Paul Baldock  
Sent: Sunday, May 31, 2020 10:06 PM
To: Peter Dougherty ; elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR
issues)

A few things I observe on my KPA 1500:

On 6m the KPA1500 reads 1.3/1.4:1 into a perfect load.  FYI it reads
1.2:1 in to a perfect load on 10M also, but 1.0:1 on all other
bands.Elecraft have various excuses for this.

1500W its really pushing it on 6M. Way to much compression. I run mine at
1100W out with 38W drive. as you state 90W, that's way too much drive.

As the amp warms up the output drops (on all bands), but I never exceed 38W
drive on 6M.

On FT8 I drive it to 500W out only, and the amp stays reasonably cool.

On 6M I bypass the tuner as the real antenna SWR is less than 1.5:1, and I
ignore what the KP1500 says it is.

Try the amp the way I use it and see how it goes.

Good luck

- Paul KW7Y



At 06:29 PM 5/31/2020, you wrote:
>Many here suggested that it was most likely a feedline issue, and I 
>figured this was indeed a distinct possibility.
>
>So this afternoon I replaced the feedline. I now have about 80 feet of 
>brand new LMR-400, new 83-SP1 connectors (and an Amphenol adaptor at 
>the balun since I don't have any type-N connectors here). The AA-230 
>ZOOM analyzer shows about 1.2:1 at 50.313, with resonance just below 
>the band. I'll fix that tomorrow, but 1.2 or 1.3:1 should be nothing to the
KPA.
>
>The TDR screen looks very clean, just a tiny bump where the feedline 
>goes through the (new) bulkhead connector to get into the house. See:
>https://www.dropbox.com/s/izcwvece7nt5f42/2020-05-31%2019.32.44.jpg?dl=
>0
>
>The SWR chart between 50.000 and 50.500:
>https://www.dropbox.com/s/y2xh4l1lihy2ujr/2020-05-31%2021.23.29.jpg?dl=
>0
>
>Again, I know the antenna is resonant a bit low, but this should NOT be 
>a factor. So here's what's now going on.
>
>1) Into a Cantenna dummy load, with 25W of drive from the M3s, the 
>KPA-1500 is delivering 1075W and showing 1.4:1. No problem delivering 
>power and no faults.
>
>2) With input power increased, 35W of K3s drive gives 1375W at 1.5 into 
>the Cantenna. Again, no problem delivering power to the purely resistive
load.
>Why a 1.5:1, I don't know, but fine, whatever. I can TX for 15-20 
>second periods without issue.
>
>3) When I switch over to the live antenna, with25 Watts of drive from 
>the K3s into the actual antenna and the amp faults out instantly in 
>bypass. When the amplifier is in bypass and the tuner is in bypass, and 
>when the K3s is delivering about 90W in FT8 mode, the front panel on 
>the KPA-1500 says the SWR is 1.9:1. When I press the TUNE button on the 
>radio, it's showing an SWR of 1.4:1.
>
>4) Amp in bypass, tuner inline, press TUNE button on the K3s and the 
>front panel of the KPA-1500 is showing a perfect 1.0:1 match. It SHOULD 
>work fine like this, right?
>
>5) Pressing ONLY the OPER/STBY button to put the amp in operate (KPA 
>tuner in and untouched since step 4), the amp SOMETIMES delivers power, 
>sometimes faults out, shows an SWR of 1.7:1. Pressing the OPER/STBY 
>button again to use only exciter power, and touching NOTHING ELSE, it's 
>back to 1.1:1 with 90W of K3s drive.
>
>6) There is basically no rhyme or reason why this is happening and it's
>*somewhat* repeatable. The incredibly frustrating part is if I see a 
>needed station come up, I'll flick the amp's tuner in line and it says it's
tuned.
>Once WSJT-X keys the radio, 90 out of 100 times the amp will 
>hard-fault. If it doesn't fault on the first transmission, it 
>absolutely WILL on the second transmission.
>
>So I'm now at a complete loss to understand what's going on here. Amp 
>is fine into a resistive load. Brand-new antenna, brand new LMR-400 
>feedline, brand new connectors, the KPA-1500 is faulting out the same 
>as it did on the
>10+ year old 6M5 with a patchwork of feedlines. I can't see how this is
>anything but a problem in the KPA-1500 (S/N 0398).
>
>  - pjd
>
>-Original Message-
>From: elecraft-boun...@mailman.qth.net 
> On Behalf Of Jim Brown
>Sent: Sunday, May 31, 2020 8:22 PM
>To: elecraft@mailman.qth.net
>Subject: Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues
>
>On 5/31/2020 

Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Peter Dougherty]

This is a brand-new balun from InnovAntennas, made specifically for this
antenna, received this past Thursday. 

Note that exactly what I described was also occurring on my old setup, on an
antenna without a balun feed. 

Basically everything from the output SO-239 on the KPA-1500 on up to the top
of the tower has been replaced with brand new everything. The fault
conditions are identical to what was happening beforehand.

 - pjd

-Original Message-
From: Jack Brindle  
Sent: Sunday, May 31, 2020 9:38 PM
To: Peter Dougherty 
Cc: elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR
issues)

Balun? Is it new? What kind?
You have pretty much eliminated the KPA1500 with this test. This sounds like
a balun toroid heating up and causing problems. 
You will see perfect conditions at low power, and the AA230 will also show
things in great shape. They are not stressing the system. But 1500 watts
sure will.
Talk a better look at the antenna system. And the balun. Open it up if
possible.

And, again describe, in detail the antenna system. There is something there
to be found.

73!
Jack, W6FB


> On May 31, 2020, at 6:29 PM, Peter Dougherty  wrote:
> 
> Many here suggested that it was most likely a feedline issue, and I 
> figured this was indeed a distinct possibility.
> 
> So this afternoon I replaced the feedline. I now have about 80 feet of 
> brand new LMR-400, new 83-SP1 connectors (and an Amphenol adaptor at 
> the balun since I don't have any type-N connectors here). The AA-230 
> ZOOM analyzer shows about 1.2:1 at 50.313, with resonance just below 
> the band. I'll fix that tomorrow, but 1.2 or 1.3:1 should be nothing to
the KPA.
> 
> The TDR screen looks very clean, just a tiny bump where the feedline 
> goes through the (new) bulkhead connector to get into the house. See:
> https://www.dropbox.com/s/izcwvece7nt5f42/2020-05-31%2019.32.44.jpg?dl
> =0
> 
> The SWR chart between 50.000 and 50.500:
> https://www.dropbox.com/s/y2xh4l1lihy2ujr/2020-05-31%2021.23.29.jpg?dl
> =0
> 
> Again, I know the antenna is resonant a bit low, but this should NOT 
> be a factor. So here's what's now going on.
> 
> 1) Into a Cantenna dummy load, with 25W of drive from the M3s, the 
> KPA-1500 is delivering 1075W and showing 1.4:1. No problem delivering 
> power and no faults.
> 
> 2) With input power increased, 35W of K3s drive gives 1375W at 1.5 
> into the Cantenna. Again, no problem delivering power to the purely
resistive load.
> Why a 1.5:1, I don't know, but fine, whatever. I can TX for 15-20 
> second periods without issue.
> 
> 3) When I switch over to the live antenna, with25 Watts of drive from 
> the K3s into the actual antenna and the amp faults out instantly in 
> bypass. When the amplifier is in bypass and the tuner is in bypass, 
> and when the K3s is delivering about 90W in FT8 mode, the front panel 
> on the KPA-1500 says the SWR is 1.9:1. When I press the TUNE button on 
> the radio, it's showing an SWR of 1.4:1.
> 
> 4) Amp in bypass, tuner inline, press TUNE button on the K3s and the 
> front panel of the KPA-1500 is showing a perfect 1.0:1 match. It 
> SHOULD work fine like this, right?
> 
> 5) Pressing ONLY the OPER/STBY button to put the amp in operate (KPA 
> tuner in and untouched since step 4), the amp SOMETIMES delivers 
> power, sometimes faults out, shows an SWR of 1.7:1. Pressing the 
> OPER/STBY button again to use only exciter power, and touching NOTHING 
> ELSE, it's back to 1.1:1 with 90W of K3s drive.
> 
> 6) There is basically no rhyme or reason why this is happening and 
> it's
> *somewhat* repeatable. The incredibly frustrating part is if I see a 
> needed station come up, I'll flick the amp's tuner in line and it says
it's tuned.
> Once WSJT-X keys the radio, 90 out of 100 times the amp will 
> hard-fault. If it doesn't fault on the first transmission, it 
> absolutely WILL on the second transmission.
> 
> So I'm now at a complete loss to understand what's going on here. Amp 
> is fine into a resistive load. Brand-new antenna, brand new LMR-400 
> feedline, brand new connectors, the KPA-1500 is faulting out the same 
> as it did on the
> 10+ year old 6M5 with a patchwork of feedlines. I can't see how this 
> 10+ is
> anything but a problem in the KPA-1500 (S/N 0398).
> 
> - pjd
> 
> -Original Message-
> From: elecraft-boun...@mailman.qth.net 
>  On Behalf Of Jim Brown
> Sent: Sunday, May 31, 2020 8:22 PM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues
> 
> On 5/31/2020 9:54 AM, Jim Miller wrote:
>> Have you vetted your feedline at 1500w? Many times something might be 
>> good at low power and fail at 1500.
> 
> This is good advice. Guys who do lots of portable setup say to always 
> check the coax first, which mostly means check for a connector that's 
> bad or badly installed.
> 
> In general, if it doesn't say Amphenol or isn't stamped with a MIL 
> spec number, it's very likely to 

Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Paul Baldock]

A few things I observe on my KPA 1500:

On 6m the KPA1500 reads 1.3/1.4:1 into a perfect load.  FYI it reads 
1.2:1 in to a perfect load on 10M also, but 1.0:1 on all other 
bands.Elecraft have various excuses for this.


1500W its really pushing it on 6M. Way to much compression. I run 
mine at 1100W out with 38W drive. as you state 90W, that's way too much drive.


As the amp warms up the output drops (on all bands), but I never 
exceed 38W drive on 6M.


On FT8 I drive it to 500W out only, and the amp stays reasonably cool.

On 6M I bypass the tuner as the real antenna SWR is less than 1.5:1, 
and I ignore what the KP1500 says it is.


Try the amp the way I use it and see how it goes.

Good luck

- Paul KW7Y



At 06:29 PM 5/31/2020, you wrote:

Many here suggested that it was most likely a feedline issue, and I figured
this was indeed a distinct possibility.

So this afternoon I replaced the feedline. I now have about 80 feet of brand
new LMR-400, new 83-SP1 connectors (and an Amphenol adaptor at the balun
since I don't have any type-N connectors here). The AA-230 ZOOM analyzer
shows about 1.2:1 at 50.313, with resonance just below the band. I'll fix
that tomorrow, but 1.2 or 1.3:1 should be nothing to the KPA.

The TDR screen looks very clean, just a tiny bump where the feedline goes
through the (new) bulkhead connector to get into the house. See:
https://www.dropbox.com/s/izcwvece7nt5f42/2020-05-31%2019.32.44.jpg?dl=0

The SWR chart between 50.000 and 50.500:
https://www.dropbox.com/s/y2xh4l1lihy2ujr/2020-05-31%2021.23.29.jpg?dl=0

Again, I know the antenna is resonant a bit low, but this should NOT be a
factor. So here's what's now going on.

1) Into a Cantenna dummy load, with 25W of drive from the M3s, the KPA-1500
is delivering 1075W and showing 1.4:1. No problem delivering power and no
faults.

2) With input power increased, 35W of K3s drive gives 1375W at 1.5 into the
Cantenna. Again, no problem delivering power to the purely resistive load.
Why a 1.5:1, I don't know, but fine, whatever. I can TX for 15-20 second
periods without issue.

3) When I switch over to the live antenna, with25 Watts of drive from the
K3s into the actual antenna and the amp faults out instantly in bypass. When
the amplifier is in bypass and the tuner is in bypass, and when the K3s is
delivering about 90W in FT8 mode, the front panel on the KPA-1500 says the
SWR is 1.9:1. When I press the TUNE button on the radio, it's showing an SWR
of 1.4:1.

4) Amp in bypass, tuner inline, press TUNE button on the K3s and the front
panel of the KPA-1500 is showing a perfect 1.0:1 match. It SHOULD work fine
like this, right?

5) Pressing ONLY the OPER/STBY button to put the amp in operate (KPA tuner
in and untouched since step 4), the amp SOMETIMES delivers power, sometimes
faults out, shows an SWR of 1.7:1. Pressing the OPER/STBY button again to
use only exciter power, and touching NOTHING ELSE, it's back to 1.1:1 with
90W of K3s drive.

6) There is basically no rhyme or reason why this is happening and it's
*somewhat* repeatable. The incredibly frustrating part is if I see a needed
station come up, I'll flick the amp's tuner in line and it says it's tuned.
Once WSJT-X keys the radio, 90 out of 100 times the amp will hard-fault. If
it doesn't fault on the first transmission, it absolutely WILL on the second
transmission.

So I'm now at a complete loss to understand what's going on here. Amp is
fine into a resistive load. Brand-new antenna, brand new LMR-400 feedline,
brand new connectors, the KPA-1500 is faulting out the same as it did on the
10+ year old 6M5 with a patchwork of feedlines. I can't see how this is
anything but a problem in the KPA-1500 (S/N 0398).

 - pjd

-Original Message-
From: elecraft-boun...@mailman.qth.net  On
Behalf Of Jim Brown
Sent: Sunday, May 31, 2020 8:22 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues

On 5/31/2020 9:54 AM, Jim Miller wrote:
> Have you vetted your feedline at 1500w? Many times something might be
> good at low power and fail at 1500.

This is good advice. Guys who do lots of portable setup say to always check
the coax first, which mostly means check for a connector that's bad or badly
installed.

In general, if it doesn't say Amphenol or isn't stamped with a MIL spec
number, it's very likely to be poor quality. This includes barrels,
adapters, etc.  Also make sure that every connector is" wrench tight."

The advice to run it straight to a dummy load is right on -- if you have one
big enough. :)

73, Jim K9YC
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Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Jack Brindle via Elecraft]

Balun? Is it new? What kind?
You have pretty much eliminated the KPA1500 with this test. This sounds like a 
balun toroid heating up and causing problems. 
You will see perfect conditions at low power, and the AA230 will also show 
things in great shape. They are not stressing the system. But 1500 watts sure 
will.
Talk a better look at the antenna system. And the balun. Open it up if possible.

And, again describe, in detail the antenna system. There is something there to 
be found.

73!
Jack, W6FB


> On May 31, 2020, at 6:29 PM, Peter Dougherty  wrote:
> 
> Many here suggested that it was most likely a feedline issue, and I figured
> this was indeed a distinct possibility. 
> 
> So this afternoon I replaced the feedline. I now have about 80 feet of brand
> new LMR-400, new 83-SP1 connectors (and an Amphenol adaptor at the balun
> since I don't have any type-N connectors here). The AA-230 ZOOM analyzer
> shows about 1.2:1 at 50.313, with resonance just below the band. I'll fix
> that tomorrow, but 1.2 or 1.3:1 should be nothing to the KPA. 
> 
> The TDR screen looks very clean, just a tiny bump where the feedline goes
> through the (new) bulkhead connector to get into the house. See:
> https://www.dropbox.com/s/izcwvece7nt5f42/2020-05-31%2019.32.44.jpg?dl=0
> 
> The SWR chart between 50.000 and 50.500:
> https://www.dropbox.com/s/y2xh4l1lihy2ujr/2020-05-31%2021.23.29.jpg?dl=0
> 
> Again, I know the antenna is resonant a bit low, but this should NOT be a
> factor. So here's what's now going on.
> 
> 1) Into a Cantenna dummy load, with 25W of drive from the M3s, the KPA-1500
> is delivering 1075W and showing 1.4:1. No problem delivering power and no
> faults.
> 
> 2) With input power increased, 35W of K3s drive gives 1375W at 1.5 into the
> Cantenna. Again, no problem delivering power to the purely resistive load.
> Why a 1.5:1, I don't know, but fine, whatever. I can TX for 15-20 second
> periods without issue.
> 
> 3) When I switch over to the live antenna, with25 Watts of drive from the
> K3s into the actual antenna and the amp faults out instantly in bypass. When
> the amplifier is in bypass and the tuner is in bypass, and when the K3s is
> delivering about 90W in FT8 mode, the front panel on the KPA-1500 says the
> SWR is 1.9:1. When I press the TUNE button on the radio, it's showing an SWR
> of 1.4:1. 
> 
> 4) Amp in bypass, tuner inline, press TUNE button on the K3s and the front
> panel of the KPA-1500 is showing a perfect 1.0:1 match. It SHOULD work fine
> like this, right?
> 
> 5) Pressing ONLY the OPER/STBY button to put the amp in operate (KPA tuner
> in and untouched since step 4), the amp SOMETIMES delivers power, sometimes
> faults out, shows an SWR of 1.7:1. Pressing the OPER/STBY button again to
> use only exciter power, and touching NOTHING ELSE, it's back to 1.1:1 with
> 90W of K3s drive.
> 
> 6) There is basically no rhyme or reason why this is happening and it's
> *somewhat* repeatable. The incredibly frustrating part is if I see a needed
> station come up, I'll flick the amp's tuner in line and it says it's tuned.
> Once WSJT-X keys the radio, 90 out of 100 times the amp will hard-fault. If
> it doesn't fault on the first transmission, it absolutely WILL on the second
> transmission. 
> 
> So I'm now at a complete loss to understand what's going on here. Amp is
> fine into a resistive load. Brand-new antenna, brand new LMR-400 feedline,
> brand new connectors, the KPA-1500 is faulting out the same as it did on the
> 10+ year old 6M5 with a patchwork of feedlines. I can't see how this is
> anything but a problem in the KPA-1500 (S/N 0398).
> 
> - pjd
> 
> -Original Message-
> From: elecraft-boun...@mailman.qth.net  On
> Behalf Of Jim Brown
> Sent: Sunday, May 31, 2020 8:22 PM
> To: elecraft@mailman.qth.net
> Subject: Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues
> 
> On 5/31/2020 9:54 AM, Jim Miller wrote:
>> Have you vetted your feedline at 1500w? Many times something might be 
>> good at low power and fail at 1500.
> 
> This is good advice. Guys who do lots of portable setup say to always check
> the coax first, which mostly means check for a connector that's bad or badly
> installed.
> 
> In general, if it doesn't say Amphenol or isn't stamped with a MIL spec
> number, it's very likely to be poor quality. This includes barrels,
> adapters, etc.  Also make sure that every connector is" wrench tight."
> 
> The advice to run it straight to a dummy load is right on -- if you have one
> big enough. :)
> 
> 73, Jim K9YC
> __
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft@mailman.qth.net
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> Please help support this email list: http://www.qsl.net/donate.html Message
> delivered to li...@w2irt.net 
> 
> __
> Elecraft 

Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR issues)

[Peter Dougherty]

Many here suggested that it was most likely a feedline issue, and I figured
this was indeed a distinct possibility. 

So this afternoon I replaced the feedline. I now have about 80 feet of brand
new LMR-400, new 83-SP1 connectors (and an Amphenol adaptor at the balun
since I don't have any type-N connectors here). The AA-230 ZOOM analyzer
shows about 1.2:1 at 50.313, with resonance just below the band. I'll fix
that tomorrow, but 1.2 or 1.3:1 should be nothing to the KPA. 

The TDR screen looks very clean, just a tiny bump where the feedline goes
through the (new) bulkhead connector to get into the house. See:
https://www.dropbox.com/s/izcwvece7nt5f42/2020-05-31%2019.32.44.jpg?dl=0

The SWR chart between 50.000 and 50.500:
https://www.dropbox.com/s/y2xh4l1lihy2ujr/2020-05-31%2021.23.29.jpg?dl=0

Again, I know the antenna is resonant a bit low, but this should NOT be a
factor. So here's what's now going on.

1) Into a Cantenna dummy load, with 25W of drive from the M3s, the KPA-1500
is delivering 1075W and showing 1.4:1. No problem delivering power and no
faults.

2) With input power increased, 35W of K3s drive gives 1375W at 1.5 into the
Cantenna. Again, no problem delivering power to the purely resistive load.
Why a 1.5:1, I don't know, but fine, whatever. I can TX for 15-20 second
periods without issue.

3) When I switch over to the live antenna, with25 Watts of drive from the
K3s into the actual antenna and the amp faults out instantly in bypass. When
the amplifier is in bypass and the tuner is in bypass, and when the K3s is
delivering about 90W in FT8 mode, the front panel on the KPA-1500 says the
SWR is 1.9:1. When I press the TUNE button on the radio, it's showing an SWR
of 1.4:1. 

4) Amp in bypass, tuner inline, press TUNE button on the K3s and the front
panel of the KPA-1500 is showing a perfect 1.0:1 match. It SHOULD work fine
like this, right?

5) Pressing ONLY the OPER/STBY button to put the amp in operate (KPA tuner
in and untouched since step 4), the amp SOMETIMES delivers power, sometimes
faults out, shows an SWR of 1.7:1. Pressing the OPER/STBY button again to
use only exciter power, and touching NOTHING ELSE, it's back to 1.1:1 with
90W of K3s drive.

6) There is basically no rhyme or reason why this is happening and it's
*somewhat* repeatable. The incredibly frustrating part is if I see a needed
station come up, I'll flick the amp's tuner in line and it says it's tuned.
Once WSJT-X keys the radio, 90 out of 100 times the amp will hard-fault. If
it doesn't fault on the first transmission, it absolutely WILL on the second
transmission. 

So I'm now at a complete loss to understand what's going on here. Amp is
fine into a resistive load. Brand-new antenna, brand new LMR-400 feedline,
brand new connectors, the KPA-1500 is faulting out the same as it did on the
10+ year old 6M5 with a patchwork of feedlines. I can't see how this is
anything but a problem in the KPA-1500 (S/N 0398).

 - pjd

-Original Message-
From: elecraft-boun...@mailman.qth.net  On
Behalf Of Jim Brown
Sent: Sunday, May 31, 2020 8:22 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues

On 5/31/2020 9:54 AM, Jim Miller wrote:
> Have you vetted your feedline at 1500w? Many times something might be 
> good at low power and fail at 1500.

This is good advice. Guys who do lots of portable setup say to always check
the coax first, which mostly means check for a connector that's bad or badly
installed.

In general, if it doesn't say Amphenol or isn't stamped with a MIL spec
number, it's very likely to be poor quality. This includes barrels,
adapters, etc.  Also make sure that every connector is" wrench tight."

The advice to run it straight to a dummy load is right on -- if you have one
big enough. :)

73, Jim K9YC
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[Elecraft] Japanese Elecraft catalog

[John Evans]

It seems that Tamiya has their own Elecraft catalog.  Interesting but 
not near as interesting as OUR Elecraft.  Just search for Elecraft and 
Tamiya on the auction site.


73 - john - n0hj



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[Elecraft] KX3/KXPA100

[AB1DD]

Here's a question concerning using the KXPA100. Is it best to run the 
amp in manual, like the higher powered amps, or run in auto? I always 
hit the atu button when changing bands, but sometimes in auto it will 
drop power, and the swr is up a bit. I couldn't find any reference to 
this, but remembered manual is the recommended way with the KPA500.


--

73,
Carl
AB1DD

Resistance is futile.
(don't know about reactance, though)

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Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues

[Jim Brown]

On 5/31/2020 9:54 AM, Jim Miller wrote:

Have you vetted your feedline at 1500w? Many times something might be good
at low power and fail at 1500.


This is good advice. Guys who do lots of portable setup say to always 
check the coax first, which mostly means check for a connector that's 
bad or badly installed.


In general, if it doesn't say Amphenol or isn't stamped with a MIL spec 
number, it's very likely to be poor quality. This includes barrels, 
adapters, etc.  Also make sure that every connector is" wrench tight."


The advice to run it straight to a dummy load is right on -- if you have 
one big enough. :)


73, Jim K9YC
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Re: [Elecraft] Elecraft Net on 75M

[Paul Van Dyke]

listening on 3.940


On Sun, May 31, 2020 at 7:48 PM Ken Roberson  wrote:

> Monitoring 3875 KHZ - Ken K5DNL
>
> On Sunday, May 31, 2020, 5:18:53 PM CDT, Paul Van Dyke <
> pvandyke1...@gmail.com> wrote:
>
>
> Unfortunately, propagation really doesn't start in my area till 2400. It
> would change the WW Net to strictly a local net.  And 3.825, has a major
> net at 24:00. So right now I'm looking at 3.875
>
> Paul  KB9AVO
>
> On Sun, May 31, 2020, 5:55 PM Jan  wrote:
>
> > Hi Paul, KB9AVO in n.e. Indiana
> >
> > Will you find ANY propagation on 3920 kHz during the middle of the
> > afternoon ?
> >
> > Maybe ~ but kinda doubtful
> >
> > Regards, Jan K1ND in s.e. Michigan
> >
> >
> >
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Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues

[Lou W0FK]

Peter, how old is your amp? I have s/n 153, and had a similar issue on 6. One
of the torroids in, I believe, the low pass filter, ultimately burned out.
Smoke smells from your amp are not pleasant. The factory determined that the
torrid was delivered out of spec, and it was replaced. I suggest you get
with support and let them trouble shoot the issue. It may be something
completely different, but could still be problematic.

73, Lou W0FK



--
Sent from: http://elecraft.365791.n2.nabble.com/
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Re: [Elecraft] 40 meter SSB net

[Bill Frantz]

Thanks for running the net Steve. Paul - thanks for the relay. 
Paul had a lot of trouble copying me which isn't too surprising. 
He was very strong at S6 until the QSB got him but he always 
popped back up. My details:


AE6JVBill   NH   KX3

I was running the KX3 on an external battery at 15 watts into an 
home brew end fed antenna tuned for 40M CW and tossed about 15 
feet into a tree. The KX3 tuner got a good SWR on 7.280 MHz.


73 Bill AE6JV

On 5/31/20 at 6:03 PM, 99sun...@gmail.com (Steve Hall) wrote:


Sunday, 1845Z  7280 kHz
Due to band conditions not all info is available and may contain errors.
WM6P   Steve  GA K3sNet Control
KB9AVOPaulIN  K3s
K5APL   WesAR K2
K4FBIMikeVA K3s
W4DML Doug   TN K3
AE6JV   Bill K3s
KG5NLQ   Jeff   LA TS680
WB9JNZEric  IL  K3
AE4OY  William GAFT991
N4XV  K2
KE3NP  Fred  PAFT991A
WB4YBY   Norm MS   Ten-Tec  Orion II
WV8CPD   DanaWVFT857

-
Bill Frantz| The first thing you need when  | Periwinkle
(408)348-7900  | using a perimeter defense is a | 150 
Rivermead Rd #235
www.pwpconsult.com | perimeter. | 
Peterborough, NH 03458


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Re: [Elecraft] KPA1500 PSU fan mod - Need resistor

[Dave]

They originally sent me a load resistor that looks like a TO220 style 
transistor. That connects to PSU 50 volt output to have some load on PSU when 
in standby, this reducing birdies on 80 meters. 

They are sending me another parts (resistor?) to lower PSU fan speed which when 
idle PSU fans  are loudest thing in shack

73
Dave wo2x

Sent from my waxed string and tin cans. 

> On May 31, 2020, at 6:00 PM, Eric Norris  wrote:
> 
> 
> I am still a bit confused by this, as I thought I was installing both--it 
> consisted of two parts.  Please share what you hear from Support.
> 
> 73 Eric WD6DBM
> 
>> On Thu, May 28, 2020, 1:21 PM Dave  wrote:
>> Hi Lou
>> 
>> I think the PS minimum load kit is different than the resistor change to 
>> slow down the PSU fans. I have already done the minimum load resistor which 
>> helps to reduce the birdies on 80 meters. 
>> 
>> What I am referring to is a resistor change done in production which slows 
>> down the PSU fans when the amp is idle in standby. I have not had 
>> confirmation back from support on this yet. Support is sending me something 
>> today but I believe it is the load resistor which I have already done. 
>> 
>> Dave wo2x
>> 
>> 
>> Sent from my waxed string and tin cans. 
>> 
>> > On May 28, 2020, at 1:15 PM, Lou W0FK  wrote:
>> > 
>> > It’s E850824, KPA1500 PS Minimum Load Kit 
>> > 
>> > 
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Re: [Elecraft] Elecraft Net on 75M

[Paul Van Dyke]

Unfortunately, propagation really doesn't start in my area till 2400. It
would change the WW Net to strictly a local net.  And 3.825, has a major
net at 24:00. So right now I'm looking at 3.875

Paul  KB9AVO

On Sun, May 31, 2020, 5:55 PM Jan  wrote:

> Hi Paul, KB9AVO in n.e. Indiana
>
> Will you find ANY propagation on 3920 kHz during the middle of the
> afternoon ?
>
> Maybe ~ but kinda doubtful
>
> Regards, Jan K1ND in s.e. Michigan
>
>
>
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[Elecraft] 40 meter SSB net

[Steve Hall]

Sunday, 1845Z  7280 kHz
Due to band conditions not all info is available and may contain errors.
WM6P   Steve  GA K3sNet Control
KB9AVOPaulIN  K3s
K5APL   WesAR K2
K4FBIMikeVA K3s
W4DML Doug   TN K3
AE6JV   Bill K3s
KG5NLQ   Jeff   LA TS680
WB9JNZEric  IL  K3
AE4OY  William GAFT991
N4XV  K2
KE3NP  Fred  PAFT991A
WB4YBY   Norm MS   Ten-Tec  Orion II
WV8CPD   DanaWVFT857
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Re: [Elecraft] KPA1500 PSU fan mod - Need resistor

[Eric Norris]

I am still a bit confused by this, as I thought I was installing both--it
consisted of two parts.  Please share what you hear from Support.

73 Eric WD6DBM

On Thu, May 28, 2020, 1:21 PM Dave  wrote:

> Hi Lou
>
> I think the PS minimum load kit is different than the resistor change to
> slow down the PSU fans. I have already done the minimum load resistor which
> helps to reduce the birdies on 80 meters.
>
> What I am referring to is a resistor change done in production which slows
> down the PSU fans when the amp is idle in standby. I have not had
> confirmation back from support on this yet. Support is sending me something
> today but I believe it is the load resistor which I have already done.
>
> Dave wo2x
>
>
> Sent from my waxed string and tin cans.
>
> > On May 28, 2020, at 1:15 PM, Lou W0FK  wrote:
> >
> > It’s E850824, KPA1500 PS Minimum Load Kit
> >
> >
>
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Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues

[Gary J Ferdinand]

Rule out or in the feed line. Put the amp into a dummy load and see if it 
trips.  Good Luck.

73/Gary W2CS

> On May 31, 2020, at 12:54 PM, Jim Miller  wrote:
> 
> I run 1500w for JT65 EME. No problems. My antenna measures 1.4:1 on the
> KPA1500 swr meter and therefore never engages ATU.
> 
> Have you vetted your feedline at 1500w? Many times something might be good
> at low power and fail at 1500. neither the AA230 or K3s will stress such a
> feedline.
> 
> I believe the AA230 will do TDR. What does that show? Have you inspected
> each connector for corrosion?
> 
> jim ab3cv
> 
> On Sun, May 31, 2020 at 12:47 PM Peter Dougherty  > wrote:
> 
>> Hi all (and sorry about the blank post-I don't know what happened there).
>> 
>> 
>> 
>> I am experiencing a continuing and repeatable problem with my KPA-1500 on
>> 6m. With the amp in bypass I am able to operate normally with my K3s, but
>> the amp's meter is showing a 1.8 to 2:1 SWR on that band, despite
>> measurements on an AA-230 analyzer and the SWR meter on the K3s itself
>> showing it virtually flat (no more than 1.2:1).
>> 
>> Once the amp is placed set to operate it's still showing SWR measurements
>> of
>> 1.8:1 to 2.1:1 consistently when delivering power. If the tuner is bypassed
>> I can't run more than about 600W out before it faults. If I put the tuner
>> in
>> and click it to tune, it will deliver power just fine at 1200 or 1300 Watts
>> for ONE FT8 transmit cycle. When it goes to transmit again it hard-faults
>> with too much reflected power. Using 100W straight from the K3s there is no
>> issue whatsoever, but *any* level of power from the KPA is liable to trip
>> the excess reflected power sensor on the amp.
>> 
>> At first I thought I had an antenna problem, but yesterday I put up a brand
>> new 6m LFA and it's doing the same thing. This coming week I plan to
>> replace
>> the feedline with LMR-400--it's got a combination of 3/8" hardline and
>> RG-213 at the moment. Any thoughts on what might be going on here? Is there
>> a known-issue on 6m with the KPA?
>> 
>> 
>> -
>> 73 and Good DX
>> Peter, W2IRT
>> 
>> 
>> 
>> President, North Jersey DX Association
>> 
>> DXCC Card Checker
>> Letter O Manager, ARRL Incoming 2nd District QSL bureau
>> 
>> 
>> 
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Re: [Elecraft] Auto Information mode

[Tom]

Hi
I've seen parts of the programming interface and it looks quite good. I
think the K4 is posed to be one of the leading transceivers on the market
with its open, and well documented and supported programming interface.
Bring it on!
73 Tom va2fsq.com

-Original Message-
From: Wayne Burdick  
Sent: May 26, 2020 11:32 AM
To: Tom 
Cc: Andy Durbin ; Elecraft Reflector

Subject: Re: [Elecraft] Auto Information mode

I should have clarified: the K4 will exhibit 100% AI ("auto-info") control
and far faster update speeds.

Wayne


> On May 26, 2020, at 8:30 AM, Wayne Burdick  wrote:
> 
> Tom,
> 
> This will also be true of the K4.
> 
> 73,
> Wayne
> N6KR
> 
> 
>> On May 26, 2020, at 8:27 AM, Tom  wrote:
>> 
>> Hi
>> A little trivia:  The AI mode in the Elecraft radios is far from
complete.
>> Only a small subset of commands are available.
>> On Yaesu radios, everything done on the radios is supported with AI 
>> and you see orders of magnitude faster performance.  In fact it is so 
>> fast that you need to implement handshaking on the serial ports to 
>> prevent slower computers from buffering the incoming commands. On a 
>> Hexa Core I7-9800 CPU usage can hit 30% as it keeps up with all of 
>> the commands coming in when you turn the VFO dial rapidly. The 
>> resting CPU usage is 1% since no polling is occurring. The AI command 
>> is great especially since most of the traffic is usually just the s
meter.  So very good meter performance.
>> 73 Tom va2fsq.com



-- 
This email has been checked for viruses by Avast antivirus software.
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Re: [Elecraft] Experimental 80 Meter Elecraft Net

[Paul Van Dyke]

Correct.But But the world is so sane now  If there is day that is
better than other, please let me know all of you
 Paul KB9AVO


On Sun, May 31, 2020 at 2:31 PM Wayne Burdick  wrote:

>
> > it will shake the spiders out of your 80 meter coils
>
>
> And tip the balance of 75 m a bit in the direction of sanity, if we're
> talking about an SSB net.
>
> Wayne
> N6KR
>
>
>
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Re: [Elecraft] Experimental 80 Meter Elecraft Net

[Wayne Burdick]

> it will shake the spiders out of your 80 meter coils


And tip the balance of 75 m a bit in the direction of sanity, if we're talking 
about an SSB net.

Wayne
N6KR


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Re: [Elecraft] Experimental 80 Meter Elecraft Net

[Paul Van Dyke]

WELL

I did the Sunday afternoon guess as I thought it might be a good time ...
After 2300Z would be much better.  Is there any day better for the most of
you?? ... it will shake the spiders out of your 80 meter coils

Grin
Paul - KB9AVO

On Sun, May 31, 2020 at 1:56 PM Steve Hall <99sun...@gmail.com> wrote:

> Great.  Welcome aboard.  I would schedule it later than 1900Z as I don't
> think the band is open that early.
> I am looking at propagation predictions from your location the band is
> dead until 2300Z.
> https://voacap.com/hf/
> Steve
> WM6P
>
>
> On Sun, May 31, 2020 at 12:58 PM Paul Van Dyke 
> wrote:
>
>> There has been discussion about a possible 80 meter net.
>> I am going to see what interest there is and activate at 1900z on 3.920
>> and see what interest there is. I'm seeing the Freq is clear, but that
>> may change.
>>
>> Hope to hear you at 1900 (or after the 40 meter net)
>> If you have comments  please yell..
>>
>> 73's
>> Paul Van Dyke - KB9AVO
>>
>
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Re: [Elecraft] Problems with KRX3A

[Grant Youngman]

Glad to hear you got it working.  But you shouldn’t be seeing a signifiant 
difference between the two receivers, unless something is set differently 
between them, or there’s another issue floating around.  

Grant NQ5T

> On May 31, 2020, at 12:36 PM, Gareth M5KVK  wrote:
> 
> Well, I’ve solved the initial problem. I stripped the rig back to its 
> pre-KRX3A state and then re-installed: after checking performance.
> 
> I can only surmise that there was a poor connection somewhere, as basically 
> all I did was re-installed some TMP cables.
> 
> The performance of the SUB is poorer than I would expect. It receives signals 
> OK but at a considerably (more than -3dB) lower level.
> 
> 73
> 
> Gareth, M5KVK
> 
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[Elecraft] Experimental 80 Meter Elecraft Net

[Paul Van Dyke]

There has been discussion about a possible 80 meter net.
I am going to see what interest there is and activate at 1900z on 3.920
and see what interest there is. I'm seeing the Freq is clear, but that may
change.

Hope to hear you at 1900 (or after the 40 meter net)
If you have comments  please yell..

73's
Paul Van Dyke - KB9AVO
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Re: [Elecraft] KPA-1500 faulting on 6m; SWR issues

[Jim Miller]

I run 1500w for JT65 EME. No problems. My antenna measures 1.4:1 on the
KPA1500 swr meter and therefore never engages ATU.

Have you vetted your feedline at 1500w? Many times something might be good
at low power and fail at 1500. neither the AA230 or K3s will stress such a
feedline.

I believe the AA230 will do TDR. What does that show? Have you inspected
each connector for corrosion?

jim ab3cv

On Sun, May 31, 2020 at 12:47 PM Peter Dougherty  wrote:

> Hi all (and sorry about the blank post-I don't know what happened there).
>
>
>
> I am experiencing a continuing and repeatable problem with my KPA-1500 on
> 6m. With the amp in bypass I am able to operate normally with my K3s, but
> the amp's meter is showing a 1.8 to 2:1 SWR on that band, despite
> measurements on an AA-230 analyzer and the SWR meter on the K3s itself
> showing it virtually flat (no more than 1.2:1).
>
> Once the amp is placed set to operate it's still showing SWR measurements
> of
> 1.8:1 to 2.1:1 consistently when delivering power. If the tuner is bypassed
> I can't run more than about 600W out before it faults. If I put the tuner
> in
> and click it to tune, it will deliver power just fine at 1200 or 1300 Watts
> for ONE FT8 transmit cycle. When it goes to transmit again it hard-faults
> with too much reflected power. Using 100W straight from the K3s there is no
> issue whatsoever, but *any* level of power from the KPA is liable to trip
> the excess reflected power sensor on the amp.
>
> At first I thought I had an antenna problem, but yesterday I put up a brand
> new 6m LFA and it's doing the same thing. This coming week I plan to
> replace
> the feedline with LMR-400--it's got a combination of 3/8" hardline and
> RG-213 at the moment. Any thoughts on what might be going on here? Is there
> a known-issue on 6m with the KPA?
>
>
> -
> 73 and Good DX
> Peter, W2IRT
>
>
>
> President, North Jersey DX Association
>
> DXCC Card Checker
> Letter O Manager, ARRL Incoming 2nd District QSL bureau
>
>
>
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[Elecraft] KPA-1500 faulting on 6m; SWR issues

[Peter Dougherty]

Hi all (and sorry about the blank post-I don't know what happened there). 

 

I am experiencing a continuing and repeatable problem with my KPA-1500 on
6m. With the amp in bypass I am able to operate normally with my K3s, but
the amp's meter is showing a 1.8 to 2:1 SWR on that band, despite
measurements on an AA-230 analyzer and the SWR meter on the K3s itself
showing it virtually flat (no more than 1.2:1). 

Once the amp is placed set to operate it's still showing SWR measurements of
1.8:1 to 2.1:1 consistently when delivering power. If the tuner is bypassed
I can't run more than about 600W out before it faults. If I put the tuner in
and click it to tune, it will deliver power just fine at 1200 or 1300 Watts
for ONE FT8 transmit cycle. When it goes to transmit again it hard-faults
with too much reflected power. Using 100W straight from the K3s there is no
issue whatsoever, but *any* level of power from the KPA is liable to trip
the excess reflected power sensor on the amp.

At first I thought I had an antenna problem, but yesterday I put up a brand
new 6m LFA and it's doing the same thing. This coming week I plan to replace
the feedline with LMR-400--it's got a combination of 3/8" hardline and
RG-213 at the moment. Any thoughts on what might be going on here? Is there
a known-issue on 6m with the KPA?


-
73 and Good DX
Peter, W2IRT



President, North Jersey DX Association

DXCC Card Checker
Letter O Manager, ARRL Incoming 2nd District QSL bureau

 

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Re: [Elecraft] Problems with KRX3A

[Gareth M5KVK]

Well, I’ve solved the initial problem. I stripped the rig back to its pre-KRX3A 
state and then re-installed: after checking performance.

I can only surmise that there was a poor connection somewhere, as basically all 
I did was re-installed some TMP cables.

The performance of the SUB is poorer than I would expect. It receives signals 
OK but at a considerably (more than -3dB) lower level.

73

Gareth, M5KVK

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[Elecraft] KX3/KXPA 100 PTT problem

[Mike Kasrich]

I have an odd problem and I'm not sure what I am doing wrong or what is 
not set correctly.



The KX3 combo will not key my Acom 2000a. it was working 160-20 but now 
seems to be fubar everywhere. I was using the rig/amp to generate 30-40w 
out put to drive the big amp. I'm not sure what I have set incorrectly 
or hooked up incorrectly.  Yes I have a phono cable hooked up to the 
KXPA100 and the normal control cable between the rig and kxpa100.




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Re: [Elecraft] Elecraft CW Net Announcement

[Jim Brown]

On 5/30/2020 8:52 PM, kevinr wrote:

14050 kHz at 2200z Sunday (3 PM PDT Sunday)


I would not expect this to a happy event, in the waning hours of WPX CW. 
 That ends at 00Z, so the 40M net should be fine.


73, Jim K9YC, KU6W in WPX
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