[Elecraft] (OT) EFHW Vertical Antenna (Mike Morrow)

[stan levandowski]

Bill - and group!

I sure wish I had the brains and experience to answer these questions 
but I don't.  My expertise lies in other fields.  When they named us 
"amateurs" they must have meant me ;).

Hopefully, other listers with deeper technical knowledge will comment. 
I can only address my actual experiences.

  I can tell you is that this antenna WORKS GREAT if the measure of 
*success* is a practical one -- how many QSOs can I make, can I hold a 
QSO for more than the usual (unfortunately) 30 seconds it takes to get a 
"599 and a TU",  and are my rig's finals happy.  Most of all, can I add 
new countries to my list?

What my video shows is an end-fed (i.e. awful high impedance!) vertical 
piece of wire that uses its coax feedline's shield for the small current 
return at this impedance (as I *think* I understand it).  Above this 
halfwave, it works better than below.  So yes, it most certainly is 
*only* a halfwave antenna for 20 meters.  But I've worked DX with it on 
30 and 40 meters also.   On 20, 17, 15, 12, and 10 it's super - 
practically speaking.

Bill, my station at home is grounded to a *real* cold water pipe; I 
don't have any RF floating around at home.  Touching my rig produces 
none of the usual indications of  floating RF.  When I brought it to 
Tony's house for the video, it was not grounded.  Still didn't exhibit 
any bad habits.

I sure didn't mean to cause any controversy and I never intended to 
suggest that *my* antenna is something special - rather, it is an 
effective and far less costly alternative to the many commercial 
"portable" antennas that so many hams turn to when they decide to try 
away-from-home operating or, like me, they face rather severe antenna 
restrictions.

I don't mean to impugn the many commercial products out there.  I happen 
to own an HFp vertical and it's a good portable antenna that fits in an 
18" nylon bag.  If I'm going somewhere on an airplane, that's what I'd 
pack!  But if I want to operate closer to home - or, in my case - I want 
an alternative to the 44' non-resonant doublet in my attic which is 
oriented East-West, I can just push this vertical solution up in about 
30 seconds and have fabulous success with it.

73 to all and to all a good night (hey, Christmas is around the corner 
;)

Stan WB2LQF




On Sun, Nov 13, 2011 at 3:47 PM, Bill Ross wrote:

> Stan and group, I found this post and referenced video very 
> interesting. However I am bothered by several things.
>
> First, a multi-band antenna cannot be a “end-fed half wave” on all 
> bands. only on one band, as far as I know.
> I’ve read many articles about “end-fed half wave” antennas over the 
> years, and they have always been single band antennas with special 
> matching circuits to tune them, and most have agreed that when they 
> are a half wave on the frequency used, a counterpoise or radial is not 
> required.
> Which leads me to question the statement that a counterpoise or radial 
> other than maybe a one meter or less one is required for this antenna. 
> A 30’ antenna will only be a half wave near 20 meters, what happens on 
> the rest of the bands? I know that sometimes using 5 watts or less, 
> you might not notice a hot chassis or RF floating around, but, what is 
> going to happen when you load this antenna with 100 watts?
>
> I would appreciate hearing from others and what they think about the 
> questions I have raised.
>
> 73, Bill, k6mgo
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