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Correction. I should have said type 31 material would be better than 43 at 27 MHz, as opposed to 61 for reducing common-mode currents. If you look at the tables in the Fair-Rite catalog online, you will see that type 31 is good from 1-300 MHz, and type 43 for 25-300 Mhz. The 43 is commonly found thru surplus distributors and at hamfests etc The clamp-on type ferrites make it simple to cascade several of them together along the coax at the antenna feed-point. You could also construct a simple coaxial balun by winding 6 to 8 closely-spaced turns of coax around a short length of 4" diameter PVC pipe. If common-mode current on your coax shield is causing some of your issues, then these steps should help. It may also improve your antenna field radiation pattern as well. Please let us know if you resolved it and what steps you did or didn't use. 73, Dave

<blockquote data-quote="N5IT" data-source="post: 421362" data-attributes="member: 10745"><p>Correction. I should have said type 31 material would be better than 43 at 27 MHz, as opposed to 61 for reducing common-mode currents. If you look at the tables in the Fair-Rite catalog online, you will see that type 31 is good from 1-300 MHz, and type 43 for 25-300 Mhz.&nbsp; The 43 is commonly found thru surplus distributors and at hamfests etc&nbsp; The clamp-on type ferrites make it simple to cascade several of them together along the coax at the antenna feed-point. You could also construct a simple coaxial balun by winding 6 to 8 closely-spaced turns of coax around a short length of 4&quot; diameter PVC pipe.&nbsp; If common-mode current on your coax shield is causing some of your issues, then these steps should help. It may also improve your antenna field radiation pattern as well.&nbsp; Please let us know if you resolved it and what steps you did or didn&#039;t use. 73, Dave</p></blockquote><p></p>

[QUOTE="N5IT, post: 421362, member: 10745"] Correction. I should have said type 31 material would be better than 43 at 27 MHz, as opposed to 61 for reducing common-mode currents. If you look at the tables in the Fair-Rite catalog online, you will see that type 31 is good from 1-300 MHz, and type 43 for 25-300 Mhz. The 43 is commonly found thru surplus distributors and at hamfests etc The clamp-on type ferrites make it simple to cascade several of them together along the coax at the antenna feed-point. You could also construct a simple coaxial balun by winding 6 to 8 closely-spaced turns of coax around a short length of 4" diameter PVC pipe. If common-mode current on your coax shield is causing some of your issues, then these steps should help. It may also improve your antenna field radiation pattern as well. Please let us know if you resolved it and what steps you did or didn't use. 73, Dave [/QUOTE]

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