[Elecraft] KPA500 Hum

Don Wilhelm w3fpr at embarqmail.com
Tue Sep 27 21:59:14 EDT 2011


Dave,

Yes, you are correct, the foam may take some time to recover, but if 
loosening the bolt makes a change, then that is the problem.

I am doing well, and in fact this weekend, my antenna farm will get 
higher.  I have a crew coming over to put the VHF/UHF antenna on the 48 
foot tower - that project has been 3 years in the making, but it will 
finally happen.  My first time on VHF/UHF too, so this is a new 
adventure for me.

We should have a good party on Saturday.  3 guys willing to climb the 
tower (myself included), and at least 4 more for the ground crew.  Most 
everything is now ready to go up.  Finally, my Yaesu FT-847 will find 
some use, and I can check in with the locals on 2 meter FM.

73,
Don W3FPR

On 9/27/2011 8:51 PM, G3TJP wrote:
>
> Don, if they have crushed the foam washers, then loosening off may not 
> help if the washers cannot recover.  If they can recover, it might 
> take 24 hours or so.  If they are beneath the transformer and the 
> cells have been creased, then they will never recover.  It amazes me 
> how folks can be surprised that transformers hum and that that it 
> takes good practise to eliminate that which is caused by the stray 
> magnetic field
>
> Hope you are keeping well, buddy?  No floods, famine or limitations to 
> the height of your antenna farm HI!
>
> 73  and stay well. Dave G3TJP
>


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