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

Tue Oct 15 18:41:29 EDT 2013

If C is at max this clearly indicates the need for external capacitity. 
This can be connected to the terminals on the rear.  Typically 1000 pf 
should be adequate.  I find that necessary on my installation.

73
Bob, K4TAX

----- Original Message ----- 
From: "Mike Bryce" <prosolar at sssnet.com>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Tuesday, October 15, 2013 10:18 AM
Subject: Re: [TenTec] Antenna is up, but the coupler doesn't like 160 meters

> 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 at sssnet.com>
>> To: "Discussion of Ten-Tec Equipment" <tentec at 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 at 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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