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@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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