SWL2002:

Put you on ignore... That is, without doubt, the best advice I have seen from you on these forums! PLONK! There you go.

wb0ksl
John

Windows 8 = Windows Diablo, or Vista II if you prefer.  I hate it, but have to have it to keep myself able to run some of the newer software.  Guess it's like politics or religion to some extent. Whatever keeps your boat afloat :-)

73 de wb0ksl
John

Sent from my iPad, BTW

Quote from: W6BYU

While some of us prefer to use wire lengths that are multiples of 1/2 wavelength
because they are easy to match with simple tuners, either homebrew or commercial.


Agreed, otherwise the end fed half wave would not work out so well :-)
I think that MOST of the commercially available remote tuners, such as the SGC and others, get a bit finicky trying to feed a half wave.  The web page tables are intended to help pick a wire length that avoids that problem on all bands.  If one has a tuner that handles matching a half wave cheerfully, on all bands of interest, that clearly obviates the need for the "magic" length tables.  Sadly, my SGC-237 is not among them.  As to performance, clearly efficiency, pattern, gain are affected by the length of the random wire, but as I see the purpose of the tables of suggested lengths, it is in the light of ease in matching, not performance in the traditional sense.  If i want to work, say, 30 meters, but my tuner won't handle the match because the random wire is a half wave or multiple, then I have no "performance" at all on that band.  I see it as a matching issue only.

73 de wb0ksl
John

KB4QAA,

I think the point of the web page cited by K3ANG is that there are certain lengths that a "random" wire will be easier to match.  Many of the tuners/couplers in use have difficulty matching a "random" wire that is very close to a half wavelength at the desired frequency.  Some lengths manage to avoid that situation on all bands, and therefore the reason for such web pages.  The antenna works "better", simply because it can be matched with commonly available tuners/couplers.

73 de wb0ksl
John

Looks like when the FCC dropped the code requirement, they should have replaced it with a requirement for a diploma from Charm School.  But, alas, that would only apply to licensed hams, wouldn't it? 

73 de wb0ksl
John

Steve,

Well, it did find a match on 6 meters to the downspout, but not quickly or cheerfully.  No luck bringing up either of the two closest 6 meter repeaters, which I believe are up.  I may have to drive over a bit closer to verify that.  The idea of using the mobile as my 6 meter antenna, then un-hooking from the coax to operate mobile when the band is open is a great idea, for someone with a better memory and attention  to detail than me ;-)

I'll see if I can bring up either repeater from the mobile, and go from there.

Thanks guys,

73 de wb0ksl
John

Jon,

Thanks for the reply.  I do still live in Olathe, but the XYL finally wore me down and we live in Prairie Highlands now.  Right on the tee for the 9th hole.  And I don't even play golf!  Go figure.  But I have learned not to upset She Who Must Be Obeyed.  I can do a vertical dipole.  And I hadn't even thought about the full wave loop.  Both excellent suggestions.  I know I can't work miracles,  but I want to do the best with what I have to work with.

73 de wb0ksl
John

OK, I have next to zero experience on 6 meters.  I live in a tightly controlled HOA environment.  My HF antenna is a gutter downspout and SGC tuner.  VHF and UHF antennas are inside a screened (Dacron screen) in porch.  I would like to put up at least something for 6 meters.  My choices are pretty much limited to a wire dipole on the upper inside wall of the porch, or a vertical worked against the aluminum bug screening underneath the porch flooring.  My gut inclination is toward the latter, as there should be little gain difference between the two, and anything other than local will be scrambled in polarity by the time it gets to the DX anyway.  I'll lose local horizontal polarized contacts, but gain the ability to get into a few 6 meter repeaters.  And before anyone suggests, no, I don't want to move, no, I don't have trees higher than 6 feet, no, I don't want a divorce... :-)

73 de wb0ksl
John
 

From the photos, it appears that a significant portion of the antenna is underneath the radiant (aluminum foil?) shield.  That seems equivalent to enclosing a significant portion of the antenna inside what amounts to a faraday shield.  The base of the Tarheel needs to be above the radiant shield.  Hard to say for sure, but that's what I'm seeing from the pics.

73 de wb0ksl
John

I hear there are spots here and there that are active with packet, still.  Couldn't say about Montreal.  I was one of the first six hams to build a TAPR TNC-1 back in the early '80s.  Kansas City really took off, northeast kansas and northwest missouri were a hotbed of activity.  Backbone connections as far as New Mexico.  I went pretty inactive for twenty years, and it's all but gone now.  When the last packet cluster shut down the radio link, that was it.  I still keyboard with a couple of other hams on 144.95, but that's it, except for APRS, of course.  Too bad, really, as it was a lot of fun.  Some say the internet and cell phones killed packet.  Maybe so, but still too bad.  I think there's some activity still on the west coast.  Maybe you can get a few old timers to join you, and re-animate packet in Montreal.  Right now, it's barely a Zombie in Kansas City.

73 de WB0KSL
John

Try 4800, 8N1

73 de wb0ksl
John

APRS.FI shows last position Milwaukee, 4-7-13 at 13:28:42

73 de wb0ksl

Thanks for the replies.  I could see absolutely no way it could get by without significant common mode issues.  Hadn't spent much time on the hamuniverse site.  I'll add this one to the lightbulb on a stick idea.

73 de wb0ksl, John

While mindlessly wandering the net yesterday, I came upon the following web page:

http://www.hamuniverse.com/N7AGK20metervertical.html

On hamuniverse.com.  :-) 

A bit like a coaxial vertical dipole where the coax feed is through the center of a quarter wave aluminum tube.  In this case, however, the shield floats at the top of the vertical tube, and the center conductor is attached to the top of the tube instead of continuing for the second quarter wave of the dipole.  I didn't check the date of the article to see if it was April 1.  Assuming it is intended to be a real design, I can only see it working via lots of common mode current on the outside of the shield.  If anyone has seen this, or cares to look, I am curious about it.  I'm guessing the reference to a Zepp in the title comes from the floating shield of the coax feedline.  Any comments?  Other than inviting me on a Snipe Hunt?

73 de wb0ksl, John

As I recall, the purpose of the radials on this antenna is an attempt to minimize common mode current on the coax shield.  This can have an adverse effect on the radiation pattern of the antenna, and RF in the shack.  The original antenna mounted the radials on the supporting mast below the bottom of the antenna, and a coax "jumper" was provided between the radials and the antenna feedpoint.  New radials made from other material such as copper, would be OK, but they should maintain the same length (and approximate diameter) as the original aluminum ones.  They should also be connected to the coax shield the same distance from the feedpoint as the original design.  This will help ensure the low common mode impedance desired.  Or, you could just use the antenna as is, and live with any common mode problems that result, ala J-Pole :-)

73 de wb0ksl, John