[TowerTalk] LP v SteppIR

n8de at thepoint.net n8de at thepoint.net
Fri Jan 22 12:46:40 PST 2010 

LPs can be stacked for better gain/FB by tilting them so the front  
elements are closer and the back elements are farther away.  This way,  
the spacing on higher bands is closer (optimized?) as is the spacing  
on the lower frequency bans.

This is the ORIGINAL orientation of LP elements in the work of Dr.  
Duhamel of Collins Radio in the 1950' and 1960's.

Not a very "attractive" arrangement, but effective, according to his  
work/data.

Don
N8DE

Quoting Pete Smith <n4zr at contesting.com>:

> Stacking them would be fundamentally like stacking triband or 5-band
> yagis - any stacking distance is a compromise, so you model them at
> various spacings and go with the one that looks the best, given your
> interests, the time in the sunspot cycle, etc.
>
> 73, Pete N4ZR
> Visit the Contesting Compendium at http://wiki.contesting.com
> The World Contest Station Database, updated daily at www.conteststations.com
> The Reverse Beacon Network at http://reversebeacon.net
>
>
> On 1/22/2010 3:08 PM, Doug Turnbull wrote:
>> How does one stack two log periodic antennas which operate over such a wide
>> range of frequencies?   I thought the stacking distance was dependent on the
>> frequency.   Now if one is using them so that one can take advantage of
>> signals arriving at different angles that is a different consideration.
>>
>> The SteppIR does have a very quick 2/3 second reverse pattern feature which
>> is a dream to use in contests and the additional FB ratio is especially
>> handy in these conditions.   The SteppIR can also be used for dual direction
>> work.   How does the wind loading of a 4 element SteppIR compare to the LP
>> which offers roughly the equivalent performance of a two element Yagi.
>>
>> I suppose there is no one answer for us all but SteppIR has certainly added
>> a new consideration to our choice.
>>
>>              73 Doug EI2CN
>>
>>
>>
>> -----Original Message-----
>> From: towertalk-bounces at contesting.com
>> [mailto:towertalk-bounces at contesting.com] On Behalf Of rlvz at aol.com
>> Sent: 22 January 2010 16:24
>> To: towertalk at contesting.com
>> Subject: [TowerTalk] LP v SteppIR
>>
>>
>> If your a contester and your tower can handle the extra weight and
>> windload... I like Buddy's idea.  Having stacked antennas offers tremendous
>> "take
>> off angle" and "dual direction" advantages that far outweigh the  extra 1-2
>> dB gain of the SteppIR.  Having the 2nd antenna at the better  take off
>> angle or pointed in the right direction could easily give a 10dB  advantage.
>>
>> (unless you stack SteppIRs)
>>
>> One of my 3-element SteppIR motors kicked the bucket when only  about 6
>> months old... I didn't enjoy having to drop the antenna and wait  for parts.
>>
>> That said, it was a great antenna when it  worked.
>>
>> 73,
>> Dick- K9OM
>>
>>
>>
>> In a message dated 1/22/2010 8:50:06 AM Eastern Standard Time,
>> gdadx2 at clearwire.net writes:
>>
>> Doug&  others,
>>
>> I am going to put up a new antenna this spring, and my  choices came down
>> to
>> either a LP, such as the T-10, or a 3-element  SteppIR.
>> I decided on the T-10 for several reasons.   The main  reason being I don't
>> desire moving parts, little wires and motors at 75  feet.  We get plenty of
>> lightning during the summer here so it would  only be a matter of time
>> before
>> something happened.  Weather is the  main reason I ruled out a quad also,
>> too
>> much freezing rain during the  winter.
>> Secondly, the SteppIR is too expensive;  I could stack 2 T-8's  for about
>> the same price.   Additionally, my operating style is  one of jumping from
>> band to band, and I don't want to have to tune my  antenna every time I
>> change bands, even if it takes a short amount of  time.  I think that would
>> get old rather quickly.
>> Like  transceivers, all antennas have pros and cons, what works for me
>> might
>> not  work for you.  I just want an antenna I can put up and pretty much
>> forget about.
>>
>> 73 Buddy WB4M
>>
>> --- Original Message -----
>> From: "Doug Turnbull"<turnbull at net1.ie>
>> To: "'Tower and HF  antenna construction topics.'"
>> <towertalk at contesting.com>
>> Sent:  Friday, January 22, 2010 4:39 AM
>> Subject: [TowerTalk] LP v  SteppIR
>>
>>
>>
>>> Gentlemen,
>>>      I wonder what  the attraction of the LP is when one can use a SteppIR.
>>> Am I wrong to  believe that the Fwd gain and FB are better for a Yagi of
>>> the
>>>   same number of elements tuned to the frequency of interest than an LP?
>>> Is
>>> it not the case that LP antennas have a lot of metal and  hence wind
>>> loading
>>> for what they achieve?   Wind  loading is as important to me as gain and
>>> directivity.   It  is a big balancing act.   Granted the SteppIR has a
>>>
>> good
>>
>>> bit  of electronics but in my experience they seem to be reliable.
>>>   Perhaps
>>> the SteppIR is more expensive for the same performance but  Aluminum is
>>> pretty dear.
>>>
>>>      I am not  trying to start a 'barney' but these are just my thoughts
>>>
>> and
>>
>>> it may  be that some one can correct me.   I believe that SteppIR has
>>> changed
>>> the entire technology and past  equations.
>>>
>>>                73 Doug EI2CN
>>>
>>> -----Original  Message-----
>>> From: towertalk-bounces at contesting.com
>>>   [mailto:towertalk-bounces at contesting.com] On Behalf Of
>>>
>> brahmangou at aol.com
>>
>>> Sent: 22 January 2010 02:24
>>> To:  towertalk at contesting.com
>>> Subject: Re: [TowerTalk] Single Tower, All  Band Solution ?
>>>
>>> You need to take a look at the Tennadyne T-8  log periodic. I have 8
>>>
>> towers
>>
>>> and have run most every antenna design  at one time or another and it is
>>> one
>>> of  my favorites. 5  bands, cw to ssb (try that with a trapped antenna),
>>> instant band   switching, no matching network, light and really low cost.
>>> 73,
>>>   AB5GU
>>>   _______________________________________________
>>>
>>>
>>>
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>>
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