[TowerTalk] BigIR question

[Grant Saviers]

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 at sbcglobal.net> Date: 07/12/2017  00:58  (GMT+00:00) To: 'Doug Turnbull' <turnbull at net1.ie>, john at kk9a.com, 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; 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
> Sent: 06 December 2017 12:23
> To: 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>
> Subject:	Re: [TowerTalk] BigIR question
> From:	Ed Richardson <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
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>
> _______________________________________________
>
>
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk