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Re: [IRCA] Vactrol luvin' !!



My opinion from seeing Mark's data and also using the remote pot method at
the Yachats OR DXped is that a Vactrol or even fixed resistor will provide
more consistently deep nulls at a fixed point that the remote pot will. ie
there's less variation to get the best null and less is lost from optimal
when left at a fixed point.

73 KAZ

On Sat, May 21, 2016 at 11:03 PM, Nick Hall-Patch <nhp@xxxxxxxx> wrote:

> I guess the quick answer would be....is the improved and consistent DKaz
> still up Mark?    If so, can you do a quick replacement of the Vactrol with
> your remote pot?    That should wash out the antenna quality as a
> contributor to the depth of the nulls shouldn't it?    (or would the remote
> pot control lines be longer than the 100' that you figured was the maximum
> that you could use)
>
> best wishes,
>
> Nick
>
>
> At 02:09 22-05-16, you wrote:
> ....
>
>
> Fast-forward to May 2016 and a D-Kaz that was installed with critical
>> attention to its symmetry and a uniform level above ground.  And it had a
>> Vactrol.  With this install I found 30 to 40+ db nulls on a lot more
>> stations and a lot more signals were minimized without constant re-tweaking
>> of the Vactrol.
>>
>> So my question is:  Was the null-depth improvement and consistency caused
>> by the better physical installation?  Or is because with the Vactrol
>> there's no longer any direct extension of the null-end circuit via copper
>> to a remote pot?
>>
>>
>> Cheers!
>>
>> Mark Durenberger
>> There's SO much I still don't know!
>>
>> -----Original Message----- From: Nick Hall-Patch
>> Sent: Saturday, May 21, 2016 7:36 PM
>> To: Mailing list for the International Radio Club of America
>> Subject: Re: [IRCA] Vactrol luvin' !!
>>
>> Glad you're enjoying the Vactrols Neil.  They've been in use here for
>> well over a decade with the Flags, and using Mark Connelly's clever
>> design to feed the control voltage through the matching
>> transformer....documented in a DXer's Technical Guide (IRCA Bookstore
>> has them), and posted by Mark on the web.
>>
>> Once I moved over to FLG-100's four years ago, the Vactrols had to
>> stay, so separate control lines were put out.  Not quite as elegant
>> as Mark's design, but absolutely necessary to retain the Vactrols as
>> you have been finding out.  Elegance can take a break.
>>
>> When I've used DKaz antennas, the range of control resistance seems
>> quite a bit tighter than with the Flags,so yes, I do like the 10 turn
>> pots also, though I believe Dallas Lankford used a couple of
>> resistors and a single turn pot to zero in on the desired range of
>> resistance.
>>
>>
>> best wishes,
>>
>> Nick
>>
>>
>> At 00:13 22-05-16, you wrote:
>>
>>> Where have these things been all my life and why didn't I use them in
>>> lieu
>>> of termination resistors (Rt) previously is what I must ask!  With some
>>> good weather today and a drying antenna field I did some work on two
>>> DKAZ's
>>> today and reinstalled the Vactrol setup.
>>> I have only one setup from a friend who makes his own for his DKAZ
>>> DXpeds.
>>> I will stress that having a multi turn pot or a smaller pot in series for
>>> fine tuning is very useful. No one setting is going to be optimal for
>>> every
>>> frequency or deviation from 180 degrees from beampeak but I have found a
>>> setting that seems better than anything I ever could obtain using and
>>> manually fine tuning fixed resistor combos.
>>>
>>> Here's some examples from daytime DX today. Locals on 1330 and 1430 are
>>> both at about 102 deg and 13 miles away. My DKAZ aims due west 270 deg so
>>> 90 deg should the spot of best back null per theory. 1330 WKTA's ethnic
>>> is
>>> so clobbered that I cannot hear a trace of it under WNTA.  Without
>>> touching
>>> the Vactrol pot 1430 WEEF's ethnic is also inaudible under WCMY which
>>> isn't
>>> strong and has two more stations under it. I've never had nulls this good
>>> or stable on those two before even with phasing!
>>>
>>> With the same pot setting, WHFB 1060 at 94 deg is also crushed and WRHL
>>> is
>>> basically alone. WLW and WJR aren't strong here days, but they are gone
>>> with the same pot setting and WKZO 590 is basically lost under Omaha's
>>> KXSP. Yes you can get Nebraska in the daytime in NE IL thanx to good
>>> ground
>>> conductivity. Note also that Chcago's  WRTO 1200 at 140 deg while not
>>> gone
>>> is deeply nulled with that setting. Fun also to have Clinton IA's GYer
>>> KROS
>>> 1340 dominant.
>>>
>>> I'll break out the ohm meter and measure what Rt the Vactrol is providing
>>> tomorrow and likely move the setup to my other west DKAZ as I've been
>>> having trouble getting deep back nulls since repairing it after severe
>>> storm damage.
>>>
>>> I'd recommend that anyone considering a terminated loop type of antenna
>>> strongly consider using a Vactrol as it is much faster and easier than
>>> walking back and forth manually adjusting resistances. My Vactrol is
>>> connected to the control unit with two separate wires about 250 ft long
>>> and
>>> clearly nulls aren't spoiled. A nice pure resistance is created by the
>>> Vactrol and applied to the termination end.
>>>
>>> 73 KAZ Barrington IL (35 miles NW of Chicago)
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>>> Opinions expressed in messages on this mailing list are those of the
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>>> IRCA, its editors, publishing staff, or officers
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>>
>>
>> _______________________________________________
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>> Be sure to register now for the Joint DX Convention
>> Kansas City, September 9 to 11.  Hotel space is filling up.
>> Registration info:
>> http://www.nrcdxas.org
>>
>>
>> Opinions expressed in messages on this mailing list are those of the
>> original contributors and do not necessarily reflect the opinion of the
>> IRCA, its editors, publishing staff, or officers
>>
>> For more information: http://www.ircaonline.org
>>
>> To Post a message: irca@xxxxxxxxxxxxxxxx
>> _______________________________________________
>> IRCA mailing list
>> IRCA@xxxxxxxxxxxxxxxx
>> http://montreal.kotalampi.com/mailman/listinfo/irca
>>
>> Be sure to register now for the Joint DX Convention
>> Kansas City, September 9 to 11.  Hotel space is filling up.
>> Registration info:
>> http://www.nrcdxas.org
>>
>>
>> Opinions expressed in messages on this mailing list are those of the
>> original contributors and do not necessarily reflect the opinion of the
>> IRCA, its editors, publishing staff, or officers
>>
>> For more information: http://www.ircaonline.org
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>> To Post a message: irca@xxxxxxxxxxxxxxxx
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>
>
> _______________________________________________
> IRCA mailing list
> IRCA@xxxxxxxxxxxxxxxx
> http://montreal.kotalampi.com/mailman/listinfo/irca
>
> Be sure to register now for the Joint DX Convention
> Kansas City, September 9 to 11.  Hotel space is filling up.
> Registration info:
> http://www.nrcdxas.org
>
>
> Opinions expressed in messages on this mailing list are those of the
> original contributors and do not necessarily reflect the opinion of the
> IRCA, its editors, publishing staff, or officers
>
> For more information: http://www.ircaonline.org
>
> To Post a message: irca@xxxxxxxxxxxxxxxx
>
>
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Be sure to register now for the Joint DX Convention
Kansas City, September 9 to 11.  Hotel space is filling up.
Registration info:
http://www.nrcdxas.org


Opinions expressed in messages on this mailing list are those of the original contributors and do not necessarily reflect the opinion of the IRCA, its editors, publishing staff, or officers

For more information: http://www.ircaonline.org

To Post a message: irca@xxxxxxxxxxxxxxxx