[Boatanchors] antenna question

[D C _Mac_ Macdonald]

Can't you simply buy a replacement trap for your Hy-Gain beam? 
Replacement parts ARE available! 
 
Having said that, like Dale, I see no reason why you couldn't 
simply substitute the Mosley driven element. Since the Mosley 
uses a capacitive feed system, the VSWR curve would probably 
be a bit broader than the original Hy-Gain. 
 
* * * * * * * * * * * 
* 73 - Mac, K2GKK/5 * 
* (Since 30 Nov 53) * 
* Oklahoma City, OK * 
* USAF, Ret'd 61-81 * 
** FAA, Ret'd 94-10 * 
* * * * * * * * * * * 
 
 

 
> From: parinc1 at frontier.com
> To: rayfrijr at msn.com; boatanchors at mailman.qth.net
> Date: Fri, 19 Feb 2016 08:39:16 -0500
> Subject: Re: [Boatanchors] antenna question
> 
> That should work fine Ray,
> The parasites "don't know" what is driving them. However, you may have to
> alter the DE matching scheme to achieve an acceptable SWR because the
> different (Mosley vs HyGain) parasite spacing and lengths will likely result
> in different mutual impedance.
> 
> Dale W4OP
> 
> -----Original Message-----
> From: Boatanchors [mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of
> RAY FRIESS
> Sent: Friday, February 19, 2016 1:29 AM
> To: boatanchors
> Subject: [Boatanchors] antenna question
> 
> Need some advice or observations from antenna guys here.
> I'm wondering how much interaction there is between traps and spacing in
> triband beams?    I know that the antennas are designed with certain spacing
> between the three elements, and what the traps in each do, which is
> basically to present a resonant length for each band, using
> the traps.
> 
> Here is what I am thinking:  I have a three element beam that has a bad trap
> in one side of the driven element.  It is
> a Hygain triband.   A friend of mine had his 50 foot tower come down today
> in 85 mph winds.  On top of it, he had
> a Mosley Classic 33.  The driven element seems to have survived with minimal
> damage.
>  What I am wondering is, can you "transplant" the Mosely driven element to
> the Hygain, using
> the current spacing of the Hygain.   In other words, everything would remain
> the same with the Hygain, except the
> driven element would be removed and the driven element from the Mosley would
> replace it.  Or, are the designs so different that the spacing of a triband
> elements depends in part on the design of the traps?
> 
> I thought it might be possible because each driven element is resonated on
> the three bands with its own traps.
> If the driven element of one was transplanted to the other, the three
> elements would still be resonated with the traps they have.  OR, is the
> spacing of the elements dependent on the traps too?