[TowerTalk] RG179 Chokes For TX 4-Squares

[Jim Brown]

Great information, Charlie!

Thanks Charlie and John.

73, Jim K9YC

On 2/19/2019 6:12 PM, Charlie Carroll wrote:
> For those that don't know, rg-179 was used in the rf chokes that were part of the W1FV yccc 9 element circle arrays.  I assembled well over 20 chokes to support the 3 current arrays at the pj4k.  As a result I've spent a lot of time winding 179 on to cores and building the complete units.  We had to modify John's original mechanical design due to a recurring issue with breakage of the center conductor.  Small wires and flexing/twisting of the center conductor do not work well.
> So, if I we're building transmitting chokes from scratch, consider the rg-302.  If you have to go down the 179 path, make sure you don't nick the center conductor and use a mechanical design to eliminate flexing and twisting.
>
> 73 Charlie, k1xx/vp2mmf
>
> On February 19, 2019 8:18:59 PM EST, john at kk9a.com wrote:
>> This is great 75 ohm choke information that I have never read
>> elsewhere.
>> Excellent work Jim!
>>
>> John KK9A
>>
>>
>> Jim Brown jim at audiosystemsgroup.com
>>
>>
>> On 2/19/2019 12:16 PM, N2TK, Tony wrote:
>>> For an 80M 4-sq how much loss difference is there between RG179 and
>> RG302
>>> per choke? I wouldn't think you could tell the difference, correct? I
>>> already have the RG-179.
>> About 0.05 dB. It only matters for differential mode dissipation -- the
>>
>> RG179 choke MUST be exposed to air, while the RG302 choke could be in a
>>
>> closed box.
>>
>> 73, Jim K9YC
>>
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