bob,
that's basically how I've been attacking the problem.
set c @2 and L @30
apply some rf and move between HI Z to LO Z.
When I find a spot that will result in a 2:1 swr, the L is still at 30 and the
C max
Move lower in freq and there is no solution.
right now, all I can do is think about it, I'm down in the bed with the iPad
mike
Mike Bryce, WB8VGE
the heathkit shop
SunLight energy systems
J e e p
o|||||||o
On Oct 14, 2013, at 8:27 PM, Bob McGraw - K4TAX wrote:
> Based on these numbers, the antenna should show resonance at about 1.8 MHz
> and the feedline should show resonance at about 2.75 MHz. Let me emphasize
> that these are resonance numbers are not anyway related to SWR values. With
> an instrument such as the MFJ 259 analyzer being operated as a dip meter, you
> should see a dip at or close to these two frequencies. Again, disregard any
> SWR value at this point as it is a ratio of impedance and has nothing to do
> with resonant frequency.
>
> If you are using something like a Tentec 238 or 239 tuner, connect the 600
> ohm line direct to the tuner terminals and be sure to have the jumper in
> place from Single Wire terminal to one terminal of the Balance Line
> terminals. Also for 160M you will likely need the 1000 pF cap from the
> External Cap terminal to ground. Especially true of the lower SWR/match
> takes place with the impedance switch on the low side. This is a true
> trial-and-error determination. I've found that 160M antennas are more
> problematic in terms of attaining a match than most any other band.
>
> If you have several tuners that will not match the load, then the likely
> choice is to change the length of the feedline some + or - 10 ft.
>
> Procedurally with the 239 tuner, set the inductance to maximum value and the
> capacitor value to #2. Then switch between the Lo Z #1 and Hi Z #1 positions
> noting which shows the lower SWR. Alternate adjust the Capacitor and
> inductor for the lowest reading. Should the capacitor be maxed out then
> switch to the next value.
>
> I do recall that some tuners have a reversed notation in that a capacitor
> value of 0 is maximum C while on others a value of 0 is minimum C.
> Personally, I looked inside the box to see where maximum C occurs and maximum
> L occurs with regard to the scaling and made notes accordingly.
>
> In my case for 160M and the internal balun, the Z switch required selected
> values of 3, 4, or 5 depending on frequency while the L value is about 20 to
> 24 on the 0 - 30 number scale.
>
> 73
> Bob, K4TAX
>
>
>
>
>
>
>
>
>
>
> ----- Original Message ----- From: "Mike Bryce" <prosolar@sssnet.com>
> To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> Sent: Monday, October 14, 2013 4:52 PM
> Subject: Re: [TenTec] Antenna is up, but the coupler doesn't like 160 meters
>
>
>> Jim,
>>
>>
>> The antenna is a doublet up 50 feet inverted vee style.
>>
>> It is feed with about 170 ish feet of 600 ohm open line.
>>
>> None of the couplers can find a tuning solution
>>
>>
>> All other bands work fine
>>
>>
>> Sent from my iPad at Aultman hospital.
>>
>> Mike wb8vge
>>
>>> On Oct 14, 2013, at 11:09 AM, Jim GM <jim.gmforum@gmail.com> wrote:
>>>
>>> Hi Mike, WB8VGE
>>>
>>> Hope your surgery goes well for you.
>>>
>>> I have gone and still going thru issues with my inverted L on 160M like
>>>
>>> your having.
>>>
>>>
>>> How long is your antenna? Is it a dipole or Folded dipole? I did not
>>> see on your post the answers to these questions.
>>>
>>>
>>> How high do you have it?
>>>
>>>
>>> Your going to find or have found that the tuner you have and other
>>> tuners will not work on 160M. They just cannot handle a near 50 ohm
>>> match or less no matter what they claim. All they want is your money.
>>>
>>> So you need to add additional matching out side the shack with coils
>>> and homemade capacitors made from coax cable, thats if you have a
>>> limited junk box like I do.
>>>
>>> Any ways the external matching will aid your tuner in the shack to take
>>> care of the rest.
>>>
>>> It will take some time and it is not a quick fix.
>>>
>>>
>>> --
>>> Jim K9TF
>>> _______________________________________________
>>>
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>
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