[TowerTalk] Traps and High SWR-troubleshooting problem ?

[Mike Fahmie via TowerTalk]

The coax connector shouldn't be hot!  This implies an insulation breakdown 
in the connector.  It doesn't happen at low power because breakdown 
voltage is not reached, it happens only on 15 meters because a voltage 
node probably happens to occur at the connector.  Simple answer: replace that connector.
-Mike-WA6ZTY


>________________________________
> From: Gary Marks <gmarks at neo.rr.com>
>To: towertalk at contesting.com 
>Sent: Monday, September 1, 2014 11:18 AM
>Subject: [TowerTalk] Traps and High SWR-troubleshooting problem ?
> 
>
>I have a Hy-Gain TH7-DX antenna that has a high SWR on 15M ONLY. With only about 30 watts power, the SWR is 1.5 to 1 but as soon as about 300 to 400 watts are applied, the SWR jumps to over 4 to 1.
>It works perfectly on 10M & 20M.  I removed all the 15M traps looking for carbon tracking, dis-assembled them and wire brushed the coils and cleaned them with solvent. 
>
>After installing all the cleaned 15M traps I still have the same problem. At that point I removed both the 10M and 15M traps and wire brushed all the traps and re-installed them again with the same high SWR problem only on 15M.  This time I kept my antenna tuner out of the system by installing a barrel connector between the in and out coax cables.
>While testing the SWR again on 15M, I just happened to touch the coax connector's (yes they were tight) at the barrel connector and they were VERY HOT. 
>
>At this point I replaced the BN-4000B balun with a new one and I still have the exact same problem.....a 4 to 1 SWR jump from 1.5 to 1 when applying over 300 watts or so on 15M ONLY.
>
>Anyone have any idea what the problem might be ?
>
>Gary
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk at contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>