Re: [IRCA] [NRC-AM] Grayland - Feb. 19-22, 2014

[Bill Whitacre <bw@xxxxxxx>]

On Mar 8, 2014, at 11:36 AM, Mark Durenberger <Mark4@xxxxxxxxxxxxxxx> wrote:

> Bill:  NICE work on your report!  That's a lot of info; easy to understand.
> 
> Interesting what you're finding with 'over-sized' D-Kaz antennas.  I had settled on a 120 ft/20ft and found it suffered a bit on the low end of the MW band...but it turned out to be hot a long way up into SW.  What height are you using with the 160-foot array?
> 
> Here's a thought that may or may not make sense.  I've often wondered if extending the null-pot to the shack might disrupt the linearity of the D-Kaz null.
> 
> When the weather's nice, I work from the null-pot location, extending the receiver feed instead.
> 
> 9:1 at the receive end is almost a perfect match to Cat5.  I run the Cat5 around to the null-pot end (staying away from the antenna).  The Cat5 feeds a 2:1 that perfectly matches the Perseus input.
> 
> (Still found some RF amplification was a good idea for the MW low-end, but the stability was rock-solid and the null was fairly uniform across a couple of octaves.)
> 
> 
> Regards,
> 
> Mark Durenberger

—

Thanks Mark.

These are the poles we use:

<http://store.kittyhawk.com/22-Foot-Heavy-Duty-Telescoping-Windsock-Pole-P1432.aspx>

They’re actually 23’ tall - KAZ made me measure.

The remote Rt replaces discrete values that I’d choose by making ‘runs’ out to the null end of the antenna, replacing resistors and taking measurements.  This is much better.  I haven’t noticed any difference in ‘wide handedness’ between remote Rt and fixed values.

I use a Wellbrook FLG-100[LN] at the ‘head end’ of the antenna so there’s no need for amplification!  The FLG gives about 20 dB of amplification and it’s PLENTY, even with 600’ of coax.

The 9:1 xfmr and pot idea came from Mark Connelly & Bruce Conti.  I gather they use that kind of set-up a lot up east but normally on much shorter antenna runs.

I’ve had good luck with it on long runs in Grayland and Lubec, ME.

The one thing I haven’t had much luck doing is phasing two DKAZ’s either in-line or broadside.  Been working with KAZ on this and I’m hoping to take another shot at broadside phasing this Spring.
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