[TowerTalk] Antenna wire source?

[Lux, Jim]

On 9/27/23 11:43 PM, Jim Pruitt wrote:
> Hello Jim.
>
> Your experience with Flexweave does not match my experience.  I had an 
> inverted vee up using flexweave and it was up for 8 years until I took 
> it down and we do get some hellacious winds here in the PNW.
>
> I was and am looking for the surplus military type wire more for 
> portable operations and that is why it is #22 or so.  Someone 
> suggested that it is copperweld wire that I am looking for.  I 
> certainly hope not as I will never use that stuff again!
>
> Thank you.
>
> Jim Pruitt
> WA7DUY
>
>
> On 9/27/2023 11:02 PM, Jim Brown wrote:
>> On 9/27/2023 9:52 PM, Jim Pruitt wrote:
>>> I wonder if anyone can tell me what the wire is called that were 
>>> used in several military surplus wire antennas. It was like 
>>> flexweave but was a bronze copper wire (I thought) and about #22awg 
>>> or so.
>>
>> Don't know about that, but for almost 20 years, I've been buying the 
>> 500 ft spools of #8 bare copper from the big box stores, and 
>> stretching it to approximate #9 hard drawn copper.
>>
>> I tried several configurations of Flex Weave about 20 years ago, and 
>> built several antennas with it. All were on the ground within a year. 
>> Another OT ham bought some and had the same results.
>>
>> 73, Jim K9YC
> _______________________________________________


If you're looking for strong and flexible, what about stainless steel 
aircraft cable?  Sure, you'll lose a bit from increased resistance, but 
maybe it's small enough to not matter.  'DUY is looking at AWG22, so 
it's already kind of lossy.

To be honest, I don't know if you can get SS flex cable that small - AWG 
22 is 0.025" (1/40th) inch.  I've seen1/32nd. (0.03125") type 304.  
(hey, Grainger has 27/1000 diameter, that's pretty close - and they have 
0.021, which is even smaller.)

SS 304 is about 2.5 times more resistive than Copper, but if we neglect 
permeability (Is 304 non-magnetic?) the skin depth is twice what it is 
in copper (at 10 MHz, 1.6 mil vs 0.8 mil), so the actual resistance is 
about the same.


304 ss is normally non-magnetic (mu of 1.005 or something like that) - 
but that might be an annealed piece.  Cold working (i.e. drawing into 
wire) can change the crystalline structure and make it magnetic, and if 
the mu goes up, then the skin depth gets thinner, so the resistance 
would rise.  That's also measured at DC - the permeability could be 
significantly different at HF.




Or, just use AWG 22 stranded, insulated copper, and let it wear out and 
fail (it's cheap).