[TowerTalk] BigIR question

[Keith Dutson]

My vertical antenna for the demonstraion was not a BigIR.  I believe the CrankIR vertical is rated 1500 watts, but have not tried it using that much power on RTTY.

 

Keith NM5G

 

From: john at kk9a.com [mailto:john at kk9a.com] 
Sent: Thursday, December 7, 2017 8:56 AM
To: Keith Dutson <kdutson at sbcglobal.net>
Cc: turnbull <turnbull at net1.ie>; towertalk at contesting.com
Subject: Re: [TowerTalk] BigIR question

 

That is surprising, can the SteppIR designs be used for legal limit  RTTY?

 

John KK9A




Sent via the Samsung Galaxy 7 edge, an AT&T 4G LTE smartphone.

 

On Thu, Dec 7, 2017 at 9:52 AM, Keith Dutson <kdutson at sbcglobal.net <mailto:kdutson at sbcglobal.net> > wrote:

That sounds reasonable.  You might want to contact SteppIR to help detect the problem.

 

I was using a vertical antenna rated for 1500 watts, but it failed using 1500 watts AM on 80 meters.  SWR went very high causing amp (Alpha 87A) to fault.  Manufacturer said it would not handle AM, only PEP.  So much for my demonstration to a friend. <grin>

 

73, Keith NM5G

 

From: turnbull [mailto:turnbull at net1.ie <mailto:turnbull at net1.ie> ] 
Sent: Thursday, December 7, 2017 2:07 AM
To: Keith Dutson <kdutson at sbcglobal.net <mailto:kdutson at sbcglobal.net> >; john at kk9a.com <mailto:john at kk9a.com> ; towertalk at contesting.com <mailto:towertalk at contesting.com> 
Subject: RE: [TowerTalk] BigIR question

 

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 at sbcglobal.net <mailto:kdutson at sbcglobal.net> > 

Date: 07/12/2017 00:58 (GMT+00:00) 

To: 'Doug Turnbull' <turnbull at net1.ie <mailto:turnbull at net1.ie> >, john at kk9a.com <mailto:john at kk9a.com> , towertalk at contesting.com <mailto:towertalk at contesting.com>  

Subject: RE: [TowerTalk] BigIR question 

 

What is your SWR on 80?

Keith NM5G

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Doug
Turnbull
Sent: Wednesday, December 6, 2017 9:56 AM
To: john at kk9a.com <mailto:john at kk9a.com> ; towertalk at contesting.com <mailto:towertalk at 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 at contesting.com] On Behalf Of
john at kk9a.com <mailto:john at kk9a.com> 
Sent: 06 December 2017 12:23
To: towertalk at contesting.com <mailto:towertalk at 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 at gmail.com <mailto:invl160 at gmail.com> >
Subject: Re: [TowerTalk] BigIR question
From: Ed Richardson <ed_richardson at shaw.ca <mailto:ed_richardson at 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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