Sent: Tuesday, June 2, 2020 10:27 AM
To: Mark Goldberg
Cc: Elecraft Mailing List
Subject: Re: [Elecraft] NOT the feedline
As a rule, if one needs a tuner to get a good match on 6M, I'd say they need to
look carefully at their antenna system. My 6M yagi shows less than 1.5:1 over
the lower 2
The Tentec 238 tuner does have some values of L and C components in the
circuit when in the Bypass mode. These are L1 which is 0.3uH and C7 &
C8 which are 250 pf in series. The tuner is designed for use between
1.8 and 30 MHz. Thus I would not advise using it as an antenna switch
on 50
I failed to mention, my antenna system is a 300 ft long horizontal loop fed
by ladder line with a homebrew two core switchable 1:1 or 4:1 Guanella
current mode Balun. The Balun has a measured return loss of about 32 dB at
50 MHz with a 200 ohm resistive load. That was surprisingly good, but
It is correct that there is no such thing as a breakdown voltage, as
stated earlier. This becomes obvious since the units are given as V/m,
which is represents Volts per meter, or Electric Field strength.
Also, unless one is measuring the field in between two plane parallel
metallic plates,
Goldberg
Sent: Tuesday, June 2, 2020 2:10 AM
To: Bob McGraw K4TAX
Cc: Elecraft Mailing List
Subject: Re: [Elecraft] NOT the feedline
I want to mention that my LDG AT-600Pro has a minimum capacitance that is
too high for a good match to my antenna on 6 meters. Certainly seems like
removing
As a rule, if one needs a tuner to get a good match on 6M, I'd say they
need to look carefully at their antenna system. My 6M yagi shows less
than 1.5:1 over the lower 2 MHz of the band, 50.0 - 52.0 MHz. The
lowest SWR occurs at 50.2 with a Z value of 42 ohms and an X value of
0.0. Of
ecraft-bounces at mailman.qth.net mailman.qth.net> On Behalf Of Walter Underwood
Sent: Monday, June 1, 2020 6:32 PM
To: Elecraft Reflector
Subject: Re: [Elecraft] NOT the feedline
Even with a 1:1 SWR, 1000 W is pretty close to the 500 V peak rating
for a UHF connector. Type N connectors are rate
alf Of Walter Underwood
Sent: Monday, June 1, 2020 6:32 PM
To: Elecraft Reflector
Subject: Re: [Elecraft] NOT the feedline
Even with a 1:1 SWR, 1000 W is pretty close to the 500 V peak rating for a UHF
connector. Type N connectors are rated at 1500 V peak.
wunder
K6WRU
Walter Underwood
CM87wj
h
I want to mention that my LDG AT-600Pro has a minimum capacitance that is
too high for a good match to my antenna on 6 meters. Certainly seems like
removing the Ten Tec tuner would be a good thing to try. Can you open the
Ten Tec tuner and use an IR thermometer to monitor the components? I don't
W3LPL
- Original Message -
From: "Jim Brown"
To: elecraft@mailman.qth.net
Sent: Tuesday, June 2, 2020 2:59:17 AM
Subject: Re: [Elecraft] NOT the feedline
On 6/1/2020 3:31 PM, Walter Underwood wrote:
> Even with a 1:1 SWR, 1000 W is pretty close to the 500
; Elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline
Pardon me if this has already been covered, but do you have the same problem if
you connect the antenna to ANT-2 on the KPA? I know you don’t want to do this
permanently, but just as a test.
Victor 4X6GP
> On 2 Jun 2020, a
...@mailman.qth.net On
Behalf Of Adrian
Sent: Monday, June 1, 2020 11:32 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline
My recent experience with Palstar has not been good. An expensive DL1500 dummy
load in which the SO239 had not been mounted correct bwith the locknut still
ten
indle
> Sent: Monday, June 1, 2020 6:09 PM
> To: Peter Dougherty
> Cc: Bob McGraw K4TAX ; elecraft@mailman.qth.net
> Subject: Re: [Elecraft] NOT the feedline
>
> Lets take another try at this. There still isn’t enough information in your
> emails to really determine what might
Plus there is L1 which is 0.3uH in the circuit and C7 and C8 in the
circuit when in the bypass position. This does not allow the tuner,
even in bypass mode, to work well as an antenna switch on 6M.
The capacitors in question are not rated for the RF current
experienced under certain load Z
My recent experience with Palstar has not been good. An expensive DL1500
dummy load in which the SO239 had not been mounted correct bwith the
locknut still ten turns loose,
requiring dismantle and repair new out of the box by myself. Also a new
expensive AT2K tuner in which the roller
My experience is that the Balun-Designs 4:1 current balun works
brilliantly on a well designed ocf antenna with decent height and
proportions to
provide good band sync at the same impedance point, where the different
band sine waves intersect, at the approx 1/3 total length feedpoint.
shown
On 6/1/2020 5:47 PM, Peter Dougherty wrote:
Ten-Tec Tuner,
This might be it, Peter. ! I've used (and loved) the Ten Tec 229 and 238
tuners, but some of their fixed capacitors are under-rated for power.
This is fairly well known among Ten Tec users, so I read about it
somewhere and
I agree with Jim, K9YC on these points.
** OCFD antennas are noted to have lots of common mode current issues.
These are a chore to tame.
** Most commercial baluns or common mode chokes are poor designs, of
inadequate material, designs copied from other poor designs but packed
in a
On 6/1/2020 3:31 PM, Walter Underwood wrote:
Even with a 1:1 SWR, 1000 W is pretty close to the 500 V peak rating for a UHF
connector.
The vast majority of HF stations with big power amps use UHF connectors
throughout, and are without such problems as long as quality connectors
are properly
On 6/1/2020 7:13 AM, Adrian wrote:
If you use a decent combination balun such as ;
https://www.balundesigns.com/model-4116-4-1-hybrid-balun-1-5-54mhz-3kw/
if you have any metal structure in range of the field, or
These are probably effective as impedance matching devices, but
everything I've
through the main antenna switch will help--I'll find out
tomorrow.
- pjd
-Original Message-
From: Jack Brindle
Sent: Monday, June 1, 2020 9:29 PM
To: Peter Dougherty
Cc: Elecraft Mailer
Subject: Re: [Elecraft] NOT the feedline
Is it the 3 element 6m LFA? That is an interesting
On 6/1/2020 6:45 AM, Alan - G4GNX wrote:
I have a similar issue with ferrite 'balun' heating, although mostly
tested on 40 metres. I'm using an OSCFD (Windom) which has a main 4:1
balun at the feed point, but also has a sleeve 'balun' consisting of 8
ferrites wrapped in a plastic sleeve, about
y
> good, quiet antenna system, but if it lets me operate without having to worry
> about hard faults all the time then I'll take that as a tradeoff.
>
> - pjd
>
> -Original Message-
> From: Jack Brindle
> Sent: Monday, June 1, 2020 6:09 PM
> To: Peter Dougher
without having to worry about
hard faults all the time then I'll take that as a tradeoff.
- pjd
-Original Message-
From: Jack Brindle
Sent: Monday, June 1, 2020 6:09 PM
To: Peter Dougherty
Cc: Bob McGraw K4TAX ; elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline
Lets take
Back to Bob K4TAX
I had a common mode current problem when I lived in Virginia and ran 100
watts barefoot, and it came as I could not do a significant angle away from
the antenna --- which I eventually solved.
I really do love the OCF idea. Through modeling it and patterns and then
careful
I had an antenna for 160m that had a fairly high SWR at the feedpoint, but
was easy to match to 50 ohms with a series inductor less than 30 feet
further down the line toward the shack. I put a common mode choke per
K9YC's designs at the antenna feedpoint, though, and even though it was
actually
Is it possible that Common mode is getting into the amp, and forcing a
fault?
73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources
On 6/1/20 2:40 PM, Fred Jensen wrote:
Nearly same experience
Even with a 1:1 SWR, 1000 W is pretty close to the 500 V peak rating for a UHF
connector. Type N connectors are rated at 1500 V peak.
wunder
K6WRU
Walter Underwood
CM87wj
http://observer.wunderwood.org/ (my blog)
> On Jun 1, 2020, at 3:17 PM, George Kidder wrote:
>
> One of my antennas is a
One of my antennas is a commercial "G5RV" fed with 33' of 450 ohm ladder
line, terminated in a PL-259 pair, with coax from there to the shack.
Apparently this combination results in very high RF voltage at the
PL-259, and it arcs over at 1000 W (not from an Elecraft amp!). This
combo goes
ites
>> overheating or may be the cause of movement of the ferrites thus
>> causing instability. Either way, heftier devices seem to be the order
>> of the day.
>>
>> Although the KPA500 temperature rise is somewhat expected, I feel it's
>> a bit higher
I am following this with great interest.
Like Alan G0GNX, I also use an OCF, RG-8X out to the current balun in this
case, 300 ohm to the antenna. K3, KPA-500 and KAT-500.
If I am running stations in a contest on 40m and also 80m CW, It "appears"
that my VSWR rises after a half hour and then the
Nearly same experience Bob: Sloping V, 135 ft legs, from top of 80 ft
tower fed with homemade 600 ohm open wire using a DX Engineering 4:1
"balun" [a strange, usually misunderstood piece of electronic apparatus
often used for the wrong reasons] rated at 10 KW. It warmed up
noticeably at 1.2
-boun...@mailman.qth.net On
Behalf Of Bob McGraw K4TAX
Sent: Monday, June 1, 2020 4:48 PM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline
Based on my experience, balun power ratings are for MATCHED conditions. It is
rare that hams use a balun in a matched condition.Thus
ature rise is somewhat expected, I feel it's
a bit higher over a short period than I would like and may be due to
reflected power.
73,
Alan. G4GNX
-- Original Message --
From: "David Olean"
To: "Peter Dougherty"
Cc: elecraft@mailman.qth.net
Sent: 01/06/2020 1
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
In that case, then it should also fault with a 50 ohm dummy load under
the same settings.
Does it ?
Adrian Fewster
Everything I'm seeing is pointing to the fault
being inside the KPA-1500 at this point.
- pjd
__
Elecraft
Message-
From: elecraft-boun...@mailman.qth.net On
Behalf Of Adrian
Sent: Monday, June 1, 2020 10:13 AM
To: Alan - G4GNX ; Elecraft Reflector
Subject: Re: [Elecraft] NOT the feedline
If you use a decent combination balun such as ;
https://www.balundesigns.com/model-4116-4-1-hybrid-balun-1-5
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
:45 AM
To: Peter Dougherty
Cc: Adrian ; Paul Baldock ; Elecraft
Mailing List
Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR
issues)
I haven't seen a discussion of your grounding system or feedline length. 6M can
be picky. What does your ground system look like
-Original Message-
From: Vic Rosenthal
Sent: Monday, June 1, 2020 12:18 AM
To: Peter Dougherty
Cc: j...@audiosystemsgroup.com; Elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR
issues)
Are you using the same output connector on the KPA1500
If you use a decent combination balun such as ;
https://www.balundesigns.com/model-4116-4-1-hybrid-balun-1-5-54mhz-3kw/
if you have any metal structure in range of the field, or
https://www.balundesigns.com/model-4115ocf-4-1-for-ocf-dipoles-1-5-54-mhz-5kw/
for a total current 4:1 balun. These
a
bit higher over a short period than I would like and may be due to
reflected power.
73,
Alan. G4GNX
-- Original Message --
From: "David Olean"
To: "Peter Dougherty"
Cc: elecraft@mailman.qth.net
Sent: 01/06/2020 13:25:18
Subject: Re: [Elecraft] NOT the fe
ay, May 31, 2020 11:05 PM
To: Peter Dougherty ; 'Paul Baldock' <
p...@paulbaldock.com>; 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 antenn
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
Watts up the pipe..
- pjd
-Original Message-
From: Adrian
Sent: Sunday, May 31, 2020 11:05 PM
To: Peter Dougherty ; 'Paul Baldock' <
p...@paulbaldock.com>; elecraft@mailman.qth.net
Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR
issues)
To remove any
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
iginal Message-
> From: Adrian
> Sent: Sunday, May 31, 2020 11:05 PM
> To: Peter Dougherty ; 'Paul Baldock' <
> p...@paulbaldock.com>; elecraft@mailman.qth.net
> Subject: Re: [Elecraft] NOT the feedline (was KPA-1500 faulting on 6m; SWR
> issues)
>
> To remove an
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
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
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
.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
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
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
Here's a thread on zipcord loss from years ago:
http://elecraft.365791.n2.nabble.com/What-your-mother-didn-t-tell-you-about-transmission-lines-td6780383.html
This is a real world result I observed:
"About 10 years ago ET3PMW was attempting to get on the low bands and only
had zip cord available
-05:00) To: Elecraft Mailing List
<elecraft@mailman.qth.net> Subject: Re: [Elecraft] Off topic feedline question
Thanks to all of you for your responses. My need for a lower impedance
parallel line is not so much a matter of loss but to minimize the impedance
transformer effect a 25’ window l
You are mistaken. 25' of ladderline is only about a tenth of a wavelength and
does not invert impedance. I suggest you download Dan's TLDetails program:
http://ac6la.com/tldetails1.html and play with it. Put in what you think, or
have measured, the feedpoint Z is then select one of the Wireman
I'm sending this again because I didn't see it come through:
You are mistaken. 25' of ladderline is only about a tenth of a wavelength and
does not invert impedance. I suggest you download Dan's TLDetails program:
http://ac6la.com/tldetails1.html and play with it. Put in what you think, or
Thanks to all of you for your responses. My need for a lower impedance
parallel line is not so much a matter of loss but to minimize the impedance
transformer effect a 25’ window line (400 ohm) has when terminated in a low
impedance load. My real concern was for the ability of the line to
Yes, googling "zip cord hf loss" yields the classic QST article:
http://www.w1npp.org/events/2010/2010-f~1/antennas/wire/790303~1.PDF
among others. Here are measurements made with a Rigexpert AA-600;
http://owenduffy.net/blog/?p=327
Bob NW8L
On Tue, 7 Nov 2017, Michael Blake wrote:
The
I didn't study this site too deeply, but KP4MD has the most appropriate
characteristics on her page, here, http://www.qsl.net/kp4md/zipcord.htm.
You might also look at Owen Duffy's pages. His transmission line calculator is
great. I think the last entry for zip 105 is zip cord, but you should
Let's try spaces instead of tabs for the tables.
Here's a summary of the sums of the scale readings (side1 plus side 2).
Keep in mind that I may have switched scales from band to band but it is the
relative numbers in each row are all on the same scale.
BandJMBDirect4to11to1
I have put 300 watts from a single 813
grounded grid amp into a doublet made
using 300 ohm twin lead. No problem.
de Joe, aa4nn
- Original Message -
From: Thom LaCosta [EMAIL PROTECTED]
To: Elecraft@mailman.qth.net
Sent: Tuesday, August 14, 2007 7:26 AM
Subject: [Elecraft] Twin Lead
Thom
There are various grades of 300 ohm twinlead.
Some are very cheap and have pretty skimpy
conductors. Some are good quality. There is/was
at least one version that was suitable for transmitting
(power level not stated that I can recall). If you
have some of the good quality stuff, you can
I have been using TruValue twin lead at $14/100 feet for the past 4
years on both my G5RV and my 40 meter loop. Works just fine. Best
bargain around. Since I only need 40 feet on either antenna, if it goes
bad, I just use the other half of what is left with some to spare.
Jozef WB2MIC
.
David
G3UNA
- Original Message -
From: Jozef Hand-Boniakowski [EMAIL PROTECTED]
To: Robert Tellefsen [EMAIL PROTECTED]
Cc: Elecraft@mailman.qth.net
Sent: Tuesday, August 14, 2007 5:02 PM
Subject: Re: [Elecraft] Twin Lead feedline
I have been using TruValue twin lead at $14/100 feet
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