From what I understand of the theory, a director is capable of slightly
(on the order of a tenth of a db) higher gain, but the tuning (spacing
and director length) is considerably more critical in order to achieve
that. I'd have to check, but it might even be that case that in order
to get it optimized you'd need to adjust the driven element length as
well. A reflector, on the other hand, gives it's best gain at wider
spacing and generally has a broader SWR curve, and also results in a
higher feedpont impedance for the driven element. I have no doubt that
the combination of those effects could make a reflector give higher gain
Unless space (or boom length on a yagi) is absolutely critical, I'd vote
for the reflector.
On 5/18/2012 7:42 AM, W8AEF wrote:
> That is not my experience. When I designed and built vertical dipole arrays
> for 20, 17, 15, 12& 10m I found the reflector arrangement always provided
> better forward gain.
> de Paul, W8AEF
> ZF2JI/ZF2TA FO8DX/FO8PLA 8Q7AA ZX0A VU7RG TX5C A52PP
> -----Original Message-----
> From: email@example.com
> Sent: Thursday, May 17, 2012 6:34 PM
> To: Tom Osborne
> Cc: Towertalk
> Subject: Re: [TowerTalk] 2 el yagi question
> A reflector will give slightly greater f/b and a director will give
> slightly higher forward gain.
> It's a toss-up, depending on your requirements.
> Quoting Tom Osborne<firstname.lastname@example.org>:
>> Hi Mike
>> I have a 40 meter vertical dipole here and am trying to decide whether
>> to put a director in front or a reflector in the back. 73
>> Tom W7WHY
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