[NLRS] Soldering elements for loop yagi

[KBØNLY]

Very good points!

The one I built was based off a design I found online, they showed it done 
by using a round file to make a notch in the wall of the pipe, the depth of 
which matched the thickness of the loop material.  So how I constructed it 
shouldn't have made a huge difference.   I should also clarify that the 
loops didn't pass through the center of the boom in my version, the holes 
were drilled by use of a drill press and a v-shaped vise to allow drilling 
them so they were just past the thickness of the outer wall, if that makes 
sense?  Without a picture I don't know how to better explain.  But if you 
picture two intersecting circles so that they just overlap that's how it 
would look.

I found that running a pipe cleaner through the holes to buff up the inside 
wall of the pipe and then applying some flux to each I could then get the 
solder to wick into the joint and effectively solder the loop to the inside 
wall of the pipe.  However its tricky soldering.  Heating the pipe enough to 
flow one joint would also reflow the previous.  Wrapping a water soaked 
towel between the one your working on and the previous one helps to wick 
away some heat, but what I ended up doing since they were held captive by 
the pipe was to set them all in place and then work from one end to another 
and solder them all in.

73,

Scott



--------------------------------------------------
From: "Donn - WA2VOI/0" <wa2voi at mninter.net>
Sent: Tuesday, June 22, 2010 5:04 PM
To: "David Palm" <thepalmhq at gmail.com>; "NLRS List" <nlrs at mailman.qth.net>; 
"Badger Contesters List" <badgercontesters at mailman.qth.net>
Subject: Re: [NLRS] Soldering elements for loop yagi

>
>
> Two comments:
> First, Yes, they will weaken and fall off... the question is how long will 
> it
> take ?  If its many years, who cares ?  If its one winter, you might want 
> to
> think about something else.  A large part of the "how long" question is 
> "what
> frequency?"  The sample is at 2.4 GHz and the loops are "small."  If 
> you're
> looking at 902, or even 1296, the loops will be larger by (about) 2X... 
> which
> means more stress on the joints and shorter life.   (Especially if they 
> get
> coated in an ice storm.  Some of that might be mitigated by mounting the 
> antenna
> "upside down," so the loops are below the boom.)  A coat of paint will 
> also help
> the longevity by blocking UV and preventing corrosion.
>
> Second, it depends on what design you are using.  The general rule for 
> copying
> an antenna design is: "COPY the design."  That means DON'T make changes 
> unless
> you have the equipment to measure the effect of the changes.  Don't use a 
> metal
> boom if the design calls for wood; don't use 1/2" elements if the design 
> calls
> for 1/8" ones, etc.  Scott's idea of passing the loops through the boom 
> will
> markedly changed the resonance frequency of the loops (make them smaller 
> by
> shorting parts to ground) UNLESS the design he copied called for that type 
> of
> mounting AND the loops were made big enough to account for that 
> originally.
> I've never seen a design for loopers that mounted elements that way (but I
> haven't seen them all, so who knows ?).  EVERY design I've ever seen calls 
> for
> mounting the loops on top of the boom with bolts through the loop ends and 
> the
> boom with nuts on the bottom of the boom.  This works all the way from 902 
> to
> 3456 MHz with excellent results.  (Loopers tend to be a bit big to mount 
> below
> 900, and a bit too small to work with above 3546.)
>
> Good luck, in any case.
>
> 73 Donn
> WA2VOI/0
>
>
> ----- Original Message ----- 
> From: "David Palm" <thepalmhq at gmail.com>
> To: "NLRS List" <nlrs at mailman.qth.net>; "Badger Contesters List"
> <badgercontesters at mailman.qth.net>
> Sent: Tuesday, June 22, 2010 9:07 PM
> Subject: [NLRS] Soldering elements for loop yagi
>
>
>>
>>
>> If I solder the elements of a loop yagi to a copper pipe boom, will the
>> solder joints hold up over time out in the weather, or will they weaken 
>> and
>> eventually let the elements drop off?
>>
>> I'm looking at a design like this:
>> http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=10127
>>
>> Thanks and 73,
>>
>> David  W9HQ
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