I had a friend who had a setup something like this and he used an old 12v
hand-held drill to turn the cap. He bought it at a flea market without a
battery, super cheap. He used a 12 supply to power the drill and turn the
cap.
Worked really good and was easy to set up. 73
tom W7WHY
On Mon, Feb 29, 2016 at 10:46 PM, Jim Brown <jim@audiosystemsgroup.com>
wrote:
> I really like the method Jim outlined here -- I've been using it on my Tee
> vertical ever since I moved to W6 ten years ago! I use a parallel
> combination of small doorknob caps to tune it.
>
> 73, Jim K9YC
>
> On Sat,11/20/2010 6:51 PM, Jim Thomson wrote:
>
>> ## Install a capacitor in series with the feedpoint of the vertical,
>> right at the base. Make the horizontal wire long enough, so the resistive
>> component is 50-60 ohms on the freq you are interested in. At that point
>> you will have some XL. Then tweak the cap so the Xc of the cap will
>> cancel out the XL on 160m. Presto, flat swr on 160m. On 80m, the cap
>> has to be shorted out. No big deal with a suitable spst relay.
>> A buddy used a motor driven 2500 pf cap... and a 100' tall vertical,
>> with an inverted vee type capacity hat on top. This entire mess was
>> suspended on a catenary line, between 2 x trees. It's flat swr across the
>> entire 200 khz.
>> Note, on some vac caps, they have a feature on em, whereby when the cap
>> is fully meshed, and then some, the plates will short out. This saves
>> you having to install a relay across the cap, in cases where you want it
>> shorted out.... as in your dual band set up.
>>
>>
>>
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