[TowerTalk] Force12 rebuild

[jimlux]

On 12/21/19 8:12 AM, Robert Harmon wrote:
> Kris,
> 
> I have a JK 403 40M yagi.  It does not use the linear loading wires like the older Force 12 did.  It uses a small shunt coil at the antenna feed points.
> How about using stainless steel rod ?
> I don't know what the diameter of the wires are but I just looked at an on line company that has 1/4" dia, 316 SS rod it up to 144" long.
> SS should outlast the alumaweld.

SS is lot more resistive than aluminum. around 75E-8 Ohm-meter
Aluminum is around 2.75E-8 Ohm-meter

You'd need to see how much current is flowing in the loading wire to see 
if that's an issue.

At least 316 is fairly non-magnetic so the skin depth isn't further reduced.



> 
> Bob
> K6UJ
> 
> 
> 
>> On Dec 21, 2019, at 7:50 AM, K9MA <k9ma at sdellington.us> wrote:
>>
>> I don't know how similar it is, but it might be worthwhile downloading the JK403 manual to see if there are any ideas there you can use.
>>
>> 73,
>> Scott K9MA
>>
>> On 12/20/2019 14:01, N5KM - Kris wrote:
>>> Hi all,
>>>
>>> I’m rebuilding my Force12 40m yagi. What would you recommend as replacement
>>> for the alumoweld linear loading wires? Some of these wires have snapped in
>>> the past due to years of vibration.
>>>
>>> Note: as part of the rebuild I am adding truss supports for the 3 elements
>>> in order to remove the stress on the linear loading wires.
>>>
>>> 73,
>>>
>>> Kris N5KM
>>> _______________________________________________
>>>
>>>
>>>
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>>
>>
>> -- 
>> Scott  K9MA
>>
>> k9ma at sdellington.us
>>
>> _______________________________________________
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