[600MRG] WG2XIQ U3 Experiment - loading a 102" pipe on 630m

[Laurence KL7 L]

Hi Dick Im using a loop here - but maybe you meant a small one :-)

Http://kl7l.com/AK600Loop.jpg

And coupler

Http://kl7l.com/coupler.jpg. (Nearly looks like this previous model from OKie Ops)

At 600m the loop is nearly resonant and doesn't need much C - prob 100pf and then just an auto transformer to resonate to circa 50 ohms

The loop pattern in the far field is

Http://kl7l.com/PatternXPQ.jpg.  

It works pretty well 

Laurence WE2XPQ



> On Jan 22, 2014, at 2:06 PM, "Dick Bingham" <dick.bingham at gmail.com> wrote:
> 
> Greetings everyone
> 
> Has anyone here messed-with a tuned loop on 600-meters. At the QRP levels
> provided by the Ultimate-3, high arc-over voltages  would, I suspect, not
> present significant problems. Correct me if I am wrong so I do not
> re-invent a failed project !
> 
> 73 - Dick/w7wkr XSH/26
> 
> On Wednesday, January 22, 2014, John Langridge <jlangridge at sbcglobal.net>
> wrote:
> 
>> Ed,
>> 
>> Not a crazy idea at all.  I've seen a number of 160m mobiles with tall
>> coils wound  on 10 inch forms plus a helical whip.. I guess they work.
>> I've used a helically wound fishing pole on 80m for fox hunting with my
>> local club and it seems ok.
>> 
>> I may work on a helical system after getting some baseline data tonight
>> with the straight whip (really 1" aluminium "antenna" pipe).  This was born
>> out of a passing comment with XKA yesterday on a similar topic.  I would be
>> interested in seeing how quickly the system improves with some top loading.
>> 
>> Congrats the XXM Ken for hearing it twice on ground wave at the ragged
>> edge of WSPR2 capabilities.  This might be a job for WSPR15.
>> 
>> 
>> SO far, the clear winner remains the 20m inverted vee with 25 feet of
>> ladder line fed as a marconi.  Don't expect it to be unseated by the 102"
>> antenna tonight but we will see.
>> 
>> 73,
>> 
>> john XIQ
>> 
>> 
>> 
>> ________________________________
>> From: Edward R Cole <kl7uw at acsalaska.net <javascript:;>>
>> To: John Langridge <jlangridge at sbcglobal.net <javascript:;>>; "
>> 600mrg at w7ekb.com <javascript:;>" <600mrg at w7ekb.com <javascript:;>>
>> Sent: Wednesday, January 22, 2014 4:18 PM
>> Subject: Re: [600MRG] WG2XIQ U3 Experiment - loading a 102" pipe on 630m
>> 
>> 
>> At 12:30 PM 1/22/2014, John Langridge wrote:
>>> Ladies and Gentlemen, for your listening pleasure, I will be running a
>> 102" pipe fed against an existing radial system from my normal QTH.  The
>> coil, as expected, was a huge challenge and needed a significant amount of
>> additional series inductance to resonate.  The match is good for the moment
>> and I am expecting no more than 5 mW ERP in WSPR2, 474.2 dial.
>>> 
>>> I fully expect this antenna to have some problem over night at some
>> point but since its running from the home station, there may be something I
>> can do.  Hopefully it will run all night and into tomorrow or until it
>> catches fire, which is a real possibility.
>>> 
>>> 
>>> 73 and thanks for listening and submitting reports.
>>> 
>>> John WG2XIQ/KB5NJD
>>> _______________________________________________
>>> 600MRG mailing list
>>> 600MRG at w7ekb.com <javascript:;>
>>> http://w7ekb.com/mailman/listinfo/600mrg_w7ekb.com
>> 
>> John,
>> 
>> 102 inches = 8 -1/2 feet!  In meters = 2.6.  So the vertical is 2.6/157.5
>> = 1.7% of a full 1/4 wave.  Wow!
>> 
>> I wonder at this length whether it might make sense to wind a helical
>> antenna to distribute the current more equally?  I guess one could
>> calculate the diameter and number turns to be resonant and tap off a the
>> ground end to match 50-ohms.
>> 
>> Suppose one wound on a 12-inch form by 10-foot; what could you use?  I
>> guess what I am thinking about is a portable antenna/mobile antenna.
>> Ground plane is problematic.
>> 
>> Maybe a crazy idea?
>> 
>> 73, Ed - KL7UW
>> 
>> 
>> 73, Ed - KL7UW
>> http://www.kl7uw.com
>>    "Kits made by KL7UW"
>> Dubus Mag business:
>>    dubususa at gmail.com <javascript:;>
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> 
> 
> -- 
> Dick Bingham - W7WKR
> Stehekin, WA    CN98pi
> 
> OR
> 
> East Wenatchee, WA  CN97uj
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