[TowerTalk] 160m Antenna Tuner Recommendation?

[Scott Neader KA9FOX]

Mike, you nailed it!  I moved the Inductor one notch away from the initial 
"best" setting and retuned and now it gladly takes 1.5kw with no 
arcing.  Thanks for the tip!!!  And thanks to everyone else for taking time 
to reply directly and/or to the list.  Many helpful tips & recommendations 
received that may be of value in the future.

Now on to the RFI reflector... now that I have big power on 160m, I am 
randomly setting off the Nighthawk AC-powered & linked CO Detectors.  For 
some reason, my family doesn't like it.

Oh, and for those that asked...QCAO = Quarter Century Appliance Operator.

- Scott KA9FOX

At 12:23 AM 11/25/2005 -0800, you wrote:
>----- Original Message -----
>From: "Scott Neader KA9FOX" <ka9fox at qth.com>
>
> >I have a 160m inverted vee fed with 75 ohm CATV.  Minimum SWR is 1.9:1
> > which isn't too far from expected given the 75 ohm cable.  I've decided to
> > just use a tuner for now, to get me QRV on top band (for the first time in
> > my life).  I will maybe improve this situation later by feeding the vee
> > with 50 ohm cable or explore transformers or other solutions.
> >
> > Unfortunately, with only about 1kw, my Dentron "Super Super Tuner" starts
> > to arc at times.  Any recommendations for a tuner that can handle 1.5kw on
> > 160m, given my relatively high SWR?  Please no home brew projects, as I am
> > a QCAO.
> >
> > Thanks in advance!
> >
> > - Scott KA9FOX
>
>Hi Scott,
>
>I have a Super-Super Tuner here which I use frequently on 160
>meters. It will handle > 1.3 KW (the output of my Drake L-7)
>depending on the load impedance. Take the cover off and note
>the dial positions corresponding to maximum and minimum
>capacitance on the variable capacitors (I use paper overlays
>on the front panel to mark tuning presets and the capacitors
>min/max positions). When you tune-up the Super-Super
>Tuner try using a different tapped inductor setting (I have always
>had less arcing using with the next to highest L value instead of the
>highest L value). You are looking for a tuning solution that maximizes
>the variable capacitor values (maximum capacitance corresponds
>to minimum RF voltage across the plates of two series variable
>capacitors). If that doesn't work, try adding some 50 ohm coax
>between the tuner and the hardline. This will move the phase of the
>load impedance which may result in more favorable tuner
>settings (you may have to experiment with the length). Assuming
>there is nothing wrong with the tuner, the arcing is occuring because
>one of the two variable capacitors is set at or near its minimum
>capacitance value.
>
>BTW, if you are using a tube amplifier with a PI-network, you
>should be able to absorb a 1.9:1 mismatch by adjusting the
>amplifier tuning a little and just skip the tuner completely. And
>finally, if you decide you must use a tuner and you can't get
>the Dentron to work, try the Ameritron ATR-30. I recently
>picked up one on the used market. I really like it.
>
>Have fun!
>
>Mike, W4EF..............................................................
>
>
>
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>
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---------------------------------------------------------------
Scott Neader KA9FOX    ka9fox at qth.com
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