[UK-CONTEST] Antenna for SSB field day

Thu Aug 12 23:03:05 PDT 2010

  Rob, maybe interpretations have changed over the years but to my thinking fanned dipoles are either a) One antenna with multiple elements or b) 
Multiple antennae with single element. Either way it doesn't seem to fit in with "One antenna only which must be a single element."

Another variant of a single element-single antenna is what I think is called the FD Special and I think has been used successfully by at least one 
group. A 40m diamond loop fed at the top corner, with a link or relay at the bottom corner. Works on 40/20/15/10 with the link closed and on 80m with 
the link open. I just checked it out in EZNEC, indicates it has useful lobes, gain and impedance figures on 40 to 10. Needs more work to look at 80m.

Over the years though, in both NFD and SSB FD Restricted sections the doublet in various lengths seems to be the most popular and most efficient. 
KISS, as they say!

You might guess I enjoy researching and playing with antennas!!

73 Chris G3SJJ

On 13/08/2010 01:37, Rob Hall M0RBY wrote:
> There are only so many variations on a theme! If a fan or common feedpoint
> dipole is classed as a single element or just a simple doublet of a length
> left up to the station concerned and any non-amplifying AMU introduced then
> I might understand the "rules" but they are a tad ambiguous and I have had a
> few differences of opinion!
>
> Again, I will use the proviso that this is my first ever contest and I
> really, really don't know.
>
> 73, Rob
>
> -----Original Message-----
> From: uk-contest-bounces at contesting.com
> [mailto:uk-contest-bounces at contesting.com] On Behalf Of Callum MØMCX
> Sent: 13 August 2010 01:01
> To: Rob Hall M0RBY
> Cc:<uk-contest at contesting.com>
> Subject: Re: [UK-CONTEST] Antenna for SSB field day
>
> Rob, you are right. Terry (G4MKP) and I knocked up a very professional
> fan dipole for 40, 20, 15 and 10 for his 5B4 holiday. Apparently it
> took just minutes to deploy and allowed 1500 QSOs on CW last fortnight
> or so. Certainly easier than a single element doublet and an auto-ATU
> - and all the fanfare that goes along with supplying 12v to an SG230
> (or similar). I've put up both and would prefer the fan everytime
> (although 15m is a bit of a squeeze).
>
> Like you though, I am also confused since a "single element" isn't a
> fan dipole.
>
> Callum McCormick
> Via iPhone
> 07976 631881
>
> http://www.facebook.com/m0mcx
> http://www.facebook.com/NordhavnDreamers
> http://www.barclayanderson.com
> http://www.m0mcx.co.uk
> http://www.dorridgevillagehall.org.uk
> http://www.dorridgescoutgroup.co.uk
>
> On 13 Aug 2010, at 00:40, "Rob Hall M0RBY"<m0rby at waylock.co.uk>  wrote:
>
>> So, I'm still confused!!!
>>
>> Its not *that* complicated to pop up a fan dipole, a friend and I,
>> an MFJ
>> and a quiet afternoon away from the kids is a pleasure, not a
>> chore!! I've
>> still got my original one here as a basis.
>>
>> Basically, can we use a fan dipole or not? Single element would
>> imply to
>> some of us a single resonant element for that frequency (so multiple,
>> parallelled resonant elements as present in a fan dipole are fine
>> and dandy)
>> and for others it simply means having one element which may or may
>> not be
>> resonant on the frequency in question and matching/rig protection is
>> done
>> using an AMU.
>>
>> I'm really looking forward to the whole technical challenge of my
>> first SSB
>> field day. Not personally particularly interested in doling out 59,
>> QRZ
>> calls but very interested in assisting in making sure that those who
>> can
>> bash a key or holler at the world are able to do so as efficiently
>> and as
>> comfortably as they can. More than happy to go out in all weathers to
>> re-tether an antenna or fetch hot nosh and brew or enter logs.
>>
>> Almost excited about my first contest!!
>>
>> Rob, M0RBY
>>
>> -----Original Message-----
>> From: uk-contest-bounces at contesting.com
>> [mailto:uk-contest-bounces at contesting.com] On Behalf Of Chris G3SJJ
>> Sent: 12 August 2010 22:07
>> Cc: uk-contest at contesting.com
>> Subject: Re: [UK-CONTEST] Antenna for SSB field day
>>
>>   Thanks Andy, I knew this had cropped up before. Phew, 20 years ago!
>>
>> Still not sure why anyone would want to use a complicated antenna
>> system as
>> opposed to a simple doublet or even a trap dipole!
>>
>> I would be careful about trying to define what is and isn't
>> acceptable as it
>> could stifle positive creativity. To my thinking the current rule is
>> adequate and allows some ingenuity. I recall some years ago (again!)
>> a group
>> using a longish doublet, maybe around 250ft per leg and bringing the
>> legs
>> round to from a Vee Beam during daylight hours on the higher bands.
>> The
>> rules need to be flexible enough to encourage and allow that choice.
>>
>> There again, times have moved on and interpretations change.
>> Everyone has
>> his own gout, as they in France!
>>
>> Chris SJJ
>>
>>
>>
>>
>> On 12/08/2010 20:55, Andy Summers wrote:
>>>    Well, this is really spooky! I sent an e-mail to the contest
>>> committee
>>> about this very subject a couple of weeks back.
>>>
>>> I have a letter from you, Chris, when you were Chairman (circa 20
>>> years
>>> ago) sitting in a filing cabinet in the shed, telling me that
>>> commoned
>>> dipoles on a single feedline were more than one antenna and broke the
>>> SSBFD rules.
>>>
>>> I suggested in my e-mail that there might be a FAQ section on the
>>> website that answers questions like these. This might help avoid such
>>> inconsistencies.
>>>
>>> In fact, can someone clarify this before September please? It might
>>> affect whether we enter this year. Not from a sour grapes point of
>>> view
>>> but from a can't use the usual hardware and lack of personnel this
>>> year
>>> point of view.
>>>
>>> 73,
>>> Andy, G4KNO.
>>>
>>> On 10/08/10 18:30, Chris G3SJJ wrote:
>>>>     I recall some discussion about this some years ago David but the
>> facts are a bit hazy (No wine, honest!) I have a feeling that at
>> some stage
>> the
>>>> rules said one element per band. Just wondering if I am confusing
>>>> this
>> with 21/28MHz contest. The 1996 Rules Supplement shows the rule as
>> now -
>> "One
>>>> antenna only which must be a single element." I would have thought a
>> stack of dipoles are one element per band but maybe the
>> interpretation has
>> changed.
>>>> Apart from the rule word, I wouldn't have thought a stack wouldn't
>>>> be so
>> efficient though as effective height could be lost, it also would be
>> very
>>>> unwieldy to erect and support. Additionally, since a 20m EDZ has
>>>> gain
>> over a dipole on that band, and on 40m with the extensions, I would
>> have
>> thought
>>>> that a better option.
>>>>
>>>> Hope that hleps the discussion.
>>>>
>>>> 73 Chris G3SJJ
>>>>
>>>>
>>>>
>>>>
>>>> On 10/08/2010 16:03, David Honey wrote:
>>>>> At 14:54 10/08/2010, Alex GM3ZBE wrote:
>>>>>> Chris, et al
>>>>>> You reminded me of a question I've meant to ask for some time.
>>>>>> I.e.
>> are
>>>>>> you allowed to change aerials during the NFD contest?  Could I
>>>>>> have
>> more
>>>>>> than one dipole and swop them as necessary during the contest.
>>>>>> Each
>>>>>> antenna being a single element? I'm talking about the restricted
>>>>>> section of course.
>>>>>> Alex 'ZBE
>>>>> When Reading and District asked the contest committee about this
>>>>> some
>>>>> years back, we were advised that a fan dipole consisting of several
>>>>> dipoles all connected to a common feedpoint did meet the criteria
>>>>> and
>>>>> could be used in the restricted or lower power sections of field
>>>>> day
>>>>> contests. One of our stations has used such an arrangement for
>>>>> several years and an official inspection during the contest did not
>>>>> raise this as an issue. If the rules, or their interpretation has
>>>>> changed, I'd like to know for sure from someone on the contest
>>>>> committee as we might consider a fan dipole in the future.
>>>>>
>>>>> We have often used a single dipole with banana plugs for band
>>>>> changes
>>>>> for CW NFD. Of course, you have to lower it to swap the plugs in
>>>>> and
>>>>> out, but at any one time, it's the same feedpoint and a single
>>>>> element dipole. There has never been a question about the legaility
>>>>> of doing that. On SSB FD where the ability to band change quickly
>>>>> to
>>>>> S&P on multipliers is important, we have used a doublet with an
>>>>> auto
>>>>> ATU on top of the mast directly at the feedpoint. That worked very
>>>>> well last year.
>>>>>
>>>>> David, M0DHO
>>>> _______________________________________________
>>>> UK-Contest mailing list
>>>> UK-Contest at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/uk-contest
>>> _______________________________________________
>>> UK-Contest mailing list
>>> UK-Contest at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/uk-contest
>>>
>> _______________________________________________
>> UK-Contest mailing list
>> UK-Contest at contesting.com
>> http://lists.contesting.com/mailman/listinfo/uk-contest
>>
>> _______________________________________________
>> UK-Contest mailing list
>> UK-Contest at contesting.com
>> http://lists.contesting.com/mailman/listinfo/uk-contest
> _______________________________________________
> UK-Contest mailing list
> UK-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/uk-contest
>
> _______________________________________________
> UK-Contest mailing list
> UK-Contest at contesting.com
> http://lists.contesting.com/mailman/listinfo/uk-contest
>