Elecraft AX2 Antenna


Ernie Bailey - N2DGQ
 

Has anyone used the Elecraft AX2 portable antenna on their QCX for field operations?  I am looking for an alternative for EFHW wire antennas.  I'm interested in comments for any portable whip antenna, AX2 notwithstanding.  Thanks for your feedback.    


Zhenxing Han N6HAN
 

If you use the AX2 as is, the SWR would be too high for QCX. A few weeks ago I used a spare qcx+ enclosure as a “weight” to mount the AX2. I also put a 3S lipo battery in it to add more weight, and I added a shunt inductor to the AX2 output to better match its impedance. I then connected the matched AX2 via a short rg316 jumper cable to my QDX. It did work pretty well. NanoVNA measured an swr around 1.4


ajparent1/kb1gmx
 

Like all shortend antennas it is low efficiency resulting in low performance..
Its a prettier version of the "Miracle antenna" of FT817 fame.

My sub for that is a load coil and a bungee cord antenna (10ft)
a stand and 6 radials 12ft long.    It works but compared to the
PAR 20M EFHW its pretty poor.  Generally 1-2 S units down from
the 20M (33ft long HW at 25ft).  Its upside and only upside is IF
you have no trees its better than no antenna at all.

THe half wave either end fed or center fed is your standard. 
A Quarter wave vertical will be poorer
A loaded vertical will be further poorer depending how much its shortend.

In antennas size really does matter.

Allison
------------------
Post online only, please no email.


Mel Snyder
 

Yeah, quarter wave verticals really do poorly.



My first test of my JPC-12/PAC-12 vertical with 2 raised radials for 20 and 40 meters with my 20 and 40 meters QCX-Minis with my then-new vertical:


Now that I’ve yearned how to use this vertical, here’s how less than 2 hours with a KX3 did with a quarter wave vertical  last week:



One hour another day:


Another day:


Another day:


These are mostly 20 CW, with a few 40 meter ventures (I usually activate mid-day/early-PM, when 40 meters has been less than idea).

Beats the hell out of my PAR Endfed, and just about any horizontal wire

Secret? — elevated radials. 

And so, I strongly disagree with your contention that “a quarter wave vertical will be poorer” (than an end fed or center fed). I tested both a PAR EFHW and an OCF (N9SAB) 40-6 meter vs the PAC-12 with an A-B coax switch. RBN validated that - at least on 20 and 40 meters - a well-designed/well-installed vertical is superior.

W3PYF

On Oct 5, 2022, at 17:03, ajparent1/kb1gmx <kb1gmx@...> wrote:

Like all shortend antennas it is low efficiency resulting in low performance..
Its a prettier version of the "Miracle antenna" of FT817 fame.

My sub for that is a load coil and a bungee cord antenna (10ft)
a stand and 6 radials 12ft long.    It works but compared to the
PAR 20M EFHW its pretty poor.  Generally 1-2 S units down from
the 20M (33ft long HW at 25ft).  Its upside and only upside is IF
you have no trees its better than no antenna at all.

THe half wave either end fed or center fed is your standard. 
A Quarter wave vertical will be poorer
A loaded vertical will be further poorer depending how much its shortend.

In antennas size really does matter.

Allison
------------------
Post online only, please no email.


Ernie Bailey - N2DGQ
 

My thanks to all valuable comments and thoughts.  I will have to research Mel's PAC-12 vertical.  My EFHW has done a Youmans job in the field.  I just like to look at alternatives to throwing a line up in the tree at least three times before I get the branch I am aiming for.  LOL.    


Duane Engle
 

Elevated radials 2-3' off the ground at 30-45 degree angles has always been the secret to high performance with verticals. Did some tests 5 years ago with an S9 and on -ground radials; then 3' off ground at 35 degrees angle. Quite impressive difference with 5 watts. Kf5GWC/qrp Duane

On Wed, Oct 5, 2022 at 9:30 PM Mel Snyder <melsnyder@...> wrote:
Yeah, quarter wave verticals really do poorly.



My first test of my JPC-12/PAC-12 vertical with 2 raised radials for 20 and 40 meters with my 20 and 40 meters QCX-Minis with my then-new vertical:


Now that I’ve yearned how to use this vertical, here’s how less than 2 hours with a KX3 did with a quarter wave vertical  last week:



One hour another day:


Another day:


Another day:


These are mostly 20 CW, with a few 40 meter ventures (I usually activate mid-day/early-PM, when 40 meters has been less than idea).

Beats the hell out of my PAR Endfed, and just about any horizontal wire

Secret? — elevated radials. 

And so, I strongly disagree with your contention that “a quarter wave vertical will be poorer” (than an end fed or center fed). I tested both a PAR EFHW and an OCF (N9SAB) 40-6 meter vs the PAC-12 with an A-B coax switch. RBN validated that - at least on 20 and 40 meters - a well-designed/well-installed vertical is superior.

W3PYF

On Oct 5, 2022, at 17:03, ajparent1/kb1gmx <kb1gmx@...> wrote:

Like all shortend antennas it is low efficiency resulting in low performance..
Its a prettier version of the "Miracle antenna" of FT817 fame.

My sub for that is a load coil and a bungee cord antenna (10ft)
a stand and 6 radials 12ft long.    It works but compared to the
PAR 20M EFHW its pretty poor.  Generally 1-2 S units down from
the 20M (33ft long HW at 25ft).  Its upside and only upside is IF
you have no trees its better than no antenna at all.

THe half wave either end fed or center fed is your standard. 
A Quarter wave vertical will be poorer
A loaded vertical will be further poorer depending how much its shortend.

In antennas size really does matter.

Allison
------------------
Post online only, please no email.