[Elecraft] AX1 Loaded Whip Antenna - Elevation and Counterpoise?

David Gilbert xdavid at cis-broadband.com
Wed Aug 7 20:13:20 EDT 2019


Rather little of this discussion makes sense to me.

Let's look at this realistically:

1.  The antenna tuner in the KX2 is rated to be good up to 10:1 SWR.  
Let's assume it's good to 15:1.

2.  Let's assume you're using a decent cable for portable operation like 
RG-8X.

3.  Let's assume that the length of your coax when operating portable is 
not much more than 30 feet long.

4.  Let's assume under the current solar flux conditions you're spending 
most of your time on 20m or lower in frequency.

30 feet of RG-8X has a loss of 0.4 db or less for that length at those 
frequencies, and per the charts in the link below the additional loss 
due to a 15:1 SWR is no more than 2 dB.

http://www.astrosurf.com/luxorion/qsl-transmission-line2.htm

Maybe it's just me, but I don't think that justifies dragging along a 
remote tuner.  You could recover a heck of a lot more dB by simply 
bringing a somewhat larger portable antenna.

73,
Dave   AB7E



On 8/7/2019 3:57 PM, Phil Hystad via Elecraft wrote:
> Sounds like an idea worth trying — I have always wondered about the coax loss between my KX3/KX2 and my portable antenna no matter which one it is (i.e. AX-1, Wire and counterpoise wires, Buddipole, etc.).
>
> But, really glad I did not sell the T1 on several occasions of thinking about selling it.  I have not used my T1 since I sold my KX1 almost three years ago.
>
> phil, K7PEH
>
>> On Aug 7, 2019, at 10:23 AM, Wayne Burdick <n6kr at elecraft.com> wrote:
>>
>> I think a T1 at the base would make a noticeable difference if the coax were more than a few feet long and the whip's resonance well removed from the target operating frequency. Short whips can be extremely narrow-banded.
>>
>> Wayne
>>
>>
>>
>>
>>> On Aug 7, 2019, at 7:40 AM, Don Wilhelm <donwilh at embarqmail.com> wrote:
>>>
>>> Bret,
>>>
>>> Yes, the T1 mounted at the antenna will reduce the potential loss in the coax.
>>>
>>> Will you notice the difference?  Maybe or maybe not.
>>>
>>> 73,
>>> Don W3FPR
>>>
>>> On 8/7/2019 7:54 AM, MaverickNH wrote:
>>>> It comes to mind I have an Elecraft T1 ATU I might try attaching directly to
>>>> the base of the AX1 rather than relying on the KX2 ATU 25-40ft from the
>>>> antenna. I try to operate closer but sometimes have to run that RG58 to
>>>> clear obstructions. Thoughts?
>>> ______________________________________________________________
>>> Elecraft mailing list
>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>>> Help: http://mailman.qth.net/mmfaq.htm
>>> Post: mailto:Elecraft at mailman.qth.net
>>>
>>> This list hosted by: http://www.qsl.net
>>> Please help support this email list: http://www.qsl.net/donate.html
>>> Message delivered to n6kr at elecraft.com
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:Elecraft at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> Message delivered to phystad at mac.com
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to xdavid at cis-broadband.com



More information about the Elecraft mailing list