[TenTec] Antenna is up, but the coupler doesn't like 160 meters

[Bob McGraw - K4TAX]

Seems like a resonance in the balun.  I'd connect the two ends of the 
balanced feed together, not using the balun, thus to form a 2 turn loop, 
couple it to the 259 being used as a dip meter and see what gives.

73
Bob, K4TAX


----- Original Message ----- 
From: "Mike Bryce" <prosolar at sssnet.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Saturday, October 12, 2013 10:59 AM
Subject: Re: [TenTec] Antenna is up, but the coupler doesn't like 160 meters


> bob and the gang,
>
> inserted the 259 and with the 1:1 balun.
>
> resonate freq is 2.487 or there abouts
>
> so the antenna as it sits is too short.
>
> I'll re-check the length with my harbor freight made in china 300 foot 
> tape and see what each leg is (length wise)
>
>
> Mike Bryce, WB8VGE
> the heathkit shop
> SunLight energy systems
> J e e p
> o|||||||o
>
>
>
>
>
>
> On Oct 12, 2013, at 10:42 AM, Bob McGraw - K4TAX wrote:
>
>> The extra / external cap is used across the capacitor bank, starting at 
>> position #4 and #5.  Both on the Low and High Z sides.  I find the text 
>> is incorrect, the schematic is correct.  Yes a .01 is way too much C by a 
>> factor of 10x.
>>
>> If you have a means to do so, what is the natural resonant frequency of 
>> the antenna?  I use my MFJ-259 as a grid dip meter effect to find the 
>> resonant frequency.  I'm not speaking of some frequency where the SWR is 
>> 1:1 or such.
>>
>> I take a different approach to antennas.  I first start with a resonant 
>> antenna at the desired frequency, then adjust the height of the antenna 
>> to attain the desired feed point impedance.  I saw Jim Brown, K9YC 
>> mentioned this in his earlier post as he used different coax impedance 
>> lines dependant on the height of the antenna.  I am not one to "prune" 
>> the length of the antenna for some SWR value.  Now in cases I know we 
>> can't get the antenna at different heights specially as we get to 160M 
>> and to some extent 80M.  In these cases, the typical height above ground 
>> does bring the center Z to 20 to 30 ohms.  Nothing wrong with this.  With 
>> low loss coax or a balanced feed, just let the tuner deal with it. 
>> That's what it is supposed to do.  I find having a resonant wire is more 
>> effective and easier to effect a good match.
>>
>> 73
>> Bob, K4TAX
>>
>>
>>
>>
>>
>
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