[TowerTalk] homemade beams

Jim White, K4OJ k4oj at tampabay.rr.com
Sat Jun 21 18:00:24 EDT 2003


Do you know a location on the web where approximate lengths are 
specified?  I have used commercials antennas which this approach but 
whenever it was time to design my own matching/gamma I took the easy 
route and ordered a compete unit from Cushcraft and used theirs...

I have not seen this as a sub routine on any of the antenna designing 
software but mebbe I missed it...

73,

Jim, K4OJ




Mirko Sibilja wrote:
> Another way to make the gamma match capacitor is to use piece of coax cable
> with braid removed, inserted into gamma tube. Calculate the neccessary
> lenght by cable's capacity/length unit.
> 
> S57AD
> ----- Original Message -----
> From: Floyd Sense <sentek at sprintmail.com>
> To: Gregg Seidl <k9kl at gbonline.com>; <TowerTalk at contesting.com>
> Sent: Friday, June 20, 2003 7:15 PM
> Subject: Re: [TowerTalk] homemade beams
> 
> 
> 
>>The gamma match cap is pretty easy.  I've always made the cap from two
>>loosely telescoping pieces of tubing, covering the inside one with shrink
>>wrap tubing.  That tube then serves as the gamma match tube and you adjust
>>the cap by moving the inner tube in or out.
>>
>>K8AC
>>----- Original Message -----
>>From: "Gregg Seidl" <k9kl at gbonline.com>
>>To: <TowerTalk at contesting.com>
>>Sent: Friday, June 20, 2003 10:14 AM
>>Subject: [TowerTalk] homemade beams
>>
>>
>>
>>>I would like to know if any one has built any of the beams in the 19th
>>>edtion Antenna book by the ARRL.I'm considering building either a 3 or 4
>>>element 20 beam.I'm thinkimg about useing a hairpin match mostly because
>>
> I
> 
>>>don't know how a gamma match works and where to find the cap that is
>>>needed.I know you need to insulate the driven elemnt from the boom on a
>>>hairpin but that I think could be done with some pvc or such,kinda like
>>>Mosley does.As a matter of fact I think I have an old Mosley center
>>
>>element
>>
>>>in the shed.Any help would be great.I know I could never come close to
>>>builing a JRC JST-245 but I think I could build a 4 element beam just as
>>>good as M2 or whatever and maybe save a few bucks to buy another
>>
>>JST-245,ok
>>
>>>maybe not!!!   Gregg  K9KL
>>>
>>>
>>>_______________________________________________
>>>
>>>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
>>
>>Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with
> 
> any
> 
>>questions and ask for Sherman, W2FLA.
>>
>>>_______________________________________________
>>>TowerTalk mailing list
>>>TowerTalk at contesting.com
>>>http://lists.contesting.com/mailman/listinfo/towertalk
>>>
>>
>>
>>_______________________________________________
>>
>>See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
> 
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
> questions and ask for Sherman, W2FLA.
> 
>>_______________________________________________
>>TowerTalk mailing list
>>TowerTalk at contesting.com
>>http://lists.contesting.com/mailman/listinfo/towertalk
> 
> 
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
> 





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