I am a mod on the SteppIR yahoo group and I have never heard of this
before. We have many many BigIR users and if this was the case it would
be a big issue. It does sound like there is a problem with this
particular setup.
Has SteppIR been contacted about it? If not it is hard to fix problems
they don't know about.
W0MU
On 12/7/2017 10:42 AM, john@kk9a.com wrote:
If that is really what is occuring and if Doug is only using 1500 watt CW
there is a design flaw. This can be easily remedied as you suggested and
it would be worth trying, even if the SteppIR is not his primary antenna.
John KK9A
Sent via the Samsung Galaxy 7 edge, an AT&T 4G LTE smartphone.
On Thu, Dec 7, 2017 at 11:56 AM, Grant Saviers <grants2@pacbell.net> wrote:
On 80 and 160 a matching ferrite transformer such as used in the CrankIR
is subject to heating with QRO rtty. The solution is a larger core -
larger diameter core or a stack or lower power on these lower frequencies.
Grant KZ1W
On 12/7/2017 0:06 AM, turnbull wrote:
Starts at about 1.2 and heads for 2 to 1. The BE is maybe 20 kHz.
This is a Hi Q device when using the loading coil. 73 Doug EI2CN
Sent from my Samsung Galaxy smartphone.
-------- Original message --------From: Keith Dutson <
kdutson@sbcglobal.net> Date: 07/12/2017 00:58 (GMT+00:00) To: 'Doug
Turnbull' <turnbull@net1.ie>, john@kk9a.com, towertalk@contesting.com
Subject: RE: [TowerTalk] BigIR question
What is your SWR on 80?
Keith NM5G
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
Doug
Turnbull
Sent: Wednesday, December 6, 2017 9:56 AM
To: john@kk9a.com; towertalk@contesting.com
Subject: Re: [TowerTalk] BigIR question
Dear OMs and YLs,
I have a BigIR mounted on an extensive radial field and also with
the
80/60M loading coil. In contests, I am allowed to run 1500W - I find
that
on 80M the antenna does not stay in tune while transmitting for a while
and
assume this is to do with heating but am not sure. Normally I would not
operate with more than 500 W for a contest on 80M then there is no
problem.
On 40M to 10M there is no such problem.
This is not my prime antenna but is a useful fallback. It is an
excellent vertical.
73 Doug EI2CN
PS Only in contests are we allowed this higher power level.
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
john@kk9a.com
Sent: 06 December 2017 12:23
To: towertalk@contesting.com
Subject: Re: [TowerTalk] BigIR question
This is a much better antenna than the fixed height 43' vertical that is
so
popular.
John KK9A
To: Frank VO1HP <invl160@gmail.com>
Subject: Re: [TowerTalk] BigIR question
From: Ed Richardson <ed_richardson@shaw.ca>
Date: Tue, 5 Dec 2017 19:44:07 -1000
Jim. The bigIR can be tuned to a quarter wave on all frequencies from 7 to
54 MHZ. On frequencies from 21-54 MHz you can select a 3/4 wavelength
mode.
I have used this antenna with raised radials, tuned stub radials and a
ground mounted radial field. Works well in all cases. It is still a
quarter wave vertical.
No magic
Ed. Ve4ear
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