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
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>> _______________________________________________
>>
>>
>>
>> _______________________________________________
>> TowerTalk mailing list
>> TowerTalk@contesting.com
>> http://lists.contesting.com/mailman/listinfo/towertalk
>>
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|