I had a similar issue with my K3s/KPA 1500 that defied logic. Without going
into all the details, I finally sent both the K3s and KPA 1500 back to
Elecraft to have them analyze it as a systems problem. It turned out to be
a faulty 100W PA on the K3s that would generate very short high level
On 6/1/2020 6:37 AM, stephen shearer wrote:
Ground loops can be another issue.
I was having a "feed back" issue with my KX3/KXPA100 ans solved it
eliminating ground/power loops.
DANGER, WILL ROBINSON!
First, ain't no such thing as a "ground loop." The real cause of
problems we BLAME on this
I have never driven the amp with 90 Watts. Ever. The 90W figure is what comes
out of the K3s *after* the amp has tripped out. With the amp in 'operate' I
feed it typically 25-35 Watts.
Here are the error codes, as requested (truncated for length--there are MANY
more):
441 20-06-01T01:02:22
The new full-length LMR-400 cable is about 3 feet longer than the old 2-section
coax I had before (old = 3/8” hardline and about 8 feet of RG-213). The entry
point is grounded to rod immediately below it, connected by 1.5” braid.
- pjd
From: Mark Goldberg
Sent: Monday, June 1, 2020
That's worth a shot. I have a ~7 foot RG-213 patch cable from the back of the
amp to the entry box. I don't have any more LMR-400 so I can't use that, but I
do have quite a bit of 213 and will make a new patch cable. That's the only bit
of the old system that's still remaining.
- pjd
Ground loops can be another issue.
I was having a "feed back" issue with my KX3/KXPA100 ans solved it
eliminating ground/power loops.
73, steve WB3LGC
On 6/1/20 8:25 AM, David Olean wrote:
Hello Peter
I suspect RFI as well. I do not have a KPA1500, so my advice is not
worth much, but the
Peter,
If my antenna system had 2.5 to 3 to 1 SWR, I would not run 1.5 KW. I'd
be looking at my antenna...
73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources
On 5/31/20 9:07 PM, Peter
Hello Peter
I suspect RFI as well. I do not have a KPA1500, so my advice is not
worth much, but the fact that the fault only occurs when a signal is
being radiated sends me a red flag. I had a similar problem here with
my SPE amplifier power output. I was measuring it on an LP-100A
On 5/31/2020 7:22 PM, Peter Dougherty wrote:
This is a brand-new balun from InnovAntennas, made specifically for this
antenna, received this past Thursday.
The word "balun" has been used to describe nearly a dozen VERY different
physical things, and is thus totally useless as a descriptor of
Is there any chance RF is getting in to the KPA1500 via an alternative
route, like one of your HF antennas, a faulty switch, loose bonding/ground,
or even a change in house wiring or wifi router, antenna rotator cable,
picking up the RF and radiating/routing it to the KPA1500 from the
antenna?
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
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
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
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
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.
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
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
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
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
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
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
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