Mike,More and longer radials will certainly never hurt and will 
likely make the antenna perform better on 75.  And in my opinion, 
adding the extra wire to the top of the antenna would be 
helpful.  Probably make the tuning a bit broader on 75 and quite 
probably make the radiator more efficient.  It would probably change 
the tuning on the other bands, but if you're already using a tuner, 
no big deal.
Not very scientivic, but my thoughts.
Pat, K9JAUAt 10:01 AM 11/13/2014, you wrote:
>Hi all:=20
>
>As most of you know, I've been running a Zero Five 43 foot vertical =
>since September 2013 and a little way into its usage, my old MFJ-986 =
>began having tuning issues with tuning the vertical on 75M.=20
>The tuner has been torn down to see if there were any real issues and =
>well, it has been beat up pretty badly. Over its 20 plus years, the =
>capacitor has been burned a little and the roller has been pitted on the =
>portion that makes contact on 75M.=20
>40/10M though has been an absolute dream. I did try another 986 tuner =
>which seemed to be better constructed and it tuned my vertical with no =
>issues on 75M but that was borrowed for a test, couldn't keep it. LOL=20
>So until I can save up for a good brand new tuner, I thought about =
>laying down about 10 66 foot radials. Right now, I have 25 25 foot =
>radials. It was also suggested by the Zero Five CHief designer, to add a =
>33 foot length of wire to the top of the vertical, forming a short =
>inverted L.=20
>If I do this, will this make the antenna easier to tune on 75M, or =
>should I see if I can borrow another tuner until I can get 1 of my own =
>because the damage to the capacitor and roller in my tuner.=20
>I'm going to be testing a couple of home brew tuners next weekend, =
>perhaps 1 of those will work and I'll be able to hang on to it. =20
>
>73:=20
>Mike VO1AX=20=