[TowerTalk] Antenna shift, VHF/UHF matching unit burning out

[Scott]

My suggestion is throw the Diamond antenna off the tower and put 
something up worthwhile. Those things are useless imo.

Scott
N1CX

At 10:23 PM 4/20/2014, Roger (K8RI) on TT wrote:
>I think that I've lost a ground.  The SWR has gone sky high on the 
>Diamond 144/440 repeater antenna. As the antenna is only rated at 
>200 watts the matching network is pretty light duty.  Also, the 
>AV640 which originally was very easy to match, is now difficult to 
>find the resonant points.
>
>I believe this is due to a DC bias through the matching transformers 
>putting the cores into, or near saturation.
>
>I keep using, I think and I believe as I really don't know, but it 
>sounds logical.
>
>The new AV840 just arrived and I need to work on the Diamond 
>antenna, so I need to find the problem before going any farther with 
>the antennas.
>
>I had been talking to N8ERF on the repeater when he mentioned I was 
>getting noisy.  I immediately stopped transmitting, came in, got the 
>SWR bridge, took it to the shop and put it in the line. The SWR had 
>gone from 1.2:1, to off scale.  I think the finals are OK.  I 
>certainly hope so.
>
>So tomorrow, I'm going to add one of those grounding plates that tie 
>everything together and to the station ground. The space behind the 
>desk out there is a mass of wire, that could be neatened up, so I 
>can see at a glance what is connected to what.
>
>That and all the projects need to be finished up so I have an 
>organized shop in which to work.
>
>Any thoughts on the grounding would be appreciated
>
>73
>
>Roger (K8RI)
>
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