[TowerTalk] JK 402 versus CC XM-240

Jeff Blaine KeepWalking188 at ac0c.com
Tue Feb 26 23:19:20 EST 2019


Tim makes a good point.  The reason a 4SQ is a great DX antenna is that 
with a quality ground, the power at the lower angles is still 
significant where a short tower mounted beam drops off fast.  The beam 
has the benefit of the "ground gain" but it's dominated by mounting 
height as you get to lower angles.  The reason beams are a winner in 
contesting is because the majority of signals come in at angles pretty 
far up off of zero, especially on 40m with an east coast US location 
working EU.

And of course the OMNI mode offered by the DXE system is a VERY handy 
tool especially for domestic contesting by guys like me located in the 
midwest where signals are coming in at all points of the compass.

73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com

On 27-Feb-19 12:03 PM, Tim Duffy wrote:
>
> With a good ground radial system (very important) here at K3LR - the 
> full size 4 square holds its own - almost 6 dB of gain over ground - 
> compared to a stack of W6NL Moxons (185 feet over 120 feet). The 
> vertical 4 square is a VERY good antenna for 40 meter DXing.
>
> 73
>
> Tim K3LR
>
> On 2019-02-26 22:54, Jeff Blaine wrote:
>
>> Jim,
>>
>> The 4sq is a great antenna but the yagi beats the 4SQ almost all the 
>> time, and often by some to a lot of s-units when it comes 
>> specifically to raw signal strength.  In some cases the difference is 
>> simply amazing.
>>
>> On the other hand the yagi won't change directions instantly and it 
>> won't provide an omni direction response.  I often run with the stack 
>> on EU and then jump to the 4-sq if I get a caller that I can't make 
>> out from another direction because he's off the side or back.  I was 
>> going to take down the 4sq but the ability to point in some other 
>> direction instantly is a real help especially in contesting.
>>
>> 73/jeff/ac0c
>> alpha-charlie-zero-charlie
>> www.ac0c.com <http://www.ac0c.com>
>>
>> On 27-Feb-19 11:31 AM, Jim wrote:
>>> WOW Jeff! There's a lot of info there! Interesting how well the 4 
>>> square works compared to the Yagi.
>>>
>>>
>>>
>>> Thanks for posting!
>>>
>>>
>>>
>>> Thanks
>>> 73
>>> Jim W7RY
>>>
>>> On 2/26/2019 7:48 PM, Jeff Blaine wrote:
>>>> Picking the "best" 40m beam is very hard on 40m and requires a 
>>>> compromise unless you have a big tower, a big rotor, moderate 
>>>> wind/ice exposure, height limitations and CW/SSB only vs. wideband 
>>>> CW+SSB.   Oh, and a serious budget of course.  That's why there are 
>>>> so many different designs in the market.
>>>>
>>>> A bit of the decision process for both the beam type selection and 
>>>> suppler may be found here for those interested:
>>>>
>>>> https://ac0c.com/main/page_acc_towersantennas_40m_stack.html
>>>>
>>>> 73/jeff/ac0c
>>>> alpha-charlie-zero-charlie
>>>> www.ac0c.com <http://www.ac0c.com>
>>>>
>>>> On 26-Feb-19 10:57 AM, john at kk9a.com <mailto:john at kk9a.com> wrote:
>>>>> Momobeam makes a T element 40m beam also, I used one last year 
>>>>> operating as
>>>>> PJ4R.  I have modeled a lot of 40m beams and it is hard to get a 
>>>>> lot of gain
>>>>> with a single antenna. The Moxon is a nice design but it does not defy
>>>>> physics.
>>>>>
>>>>> John KK9A
>>>>>
>>>>>
>>>>>
>>>>> Grant Saviers KZ1W wrote:
>>>>> All true, Jim.
>>>>>
>>>>> As well, re W6NL's design of the 40m Moxon being discussed.  I 
>>>>> built/own
>>>>> two.  Also NEC4 verified.  K3LR and 8P5A use them.  The JK Moxon looks
>>>>> like a close derivative.
>>>>>
>>>>> Grant KZ1W
>>>>>
>>>>> _______________________________________________
>>>>>
>>>>>
>>>>>
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