Topband: TopBand DownUnder

[Grant Saviers]

I've not heard the term "accordian" applied, but the Tornado Tuner 
expands and compresses a coil inside some pvc pipe to change L about 
2:1.  I have one (split) to tune the full 80m band at the center of an 
86ft rotatable dipole.  Your choice of Al or Cu coil tubing with a small 
Portescap gearhead motor driving a delrin (I think) leadscrew screw and 
reed switch for turns counting.

JKantennas makes an yagi with a Tornado.  Rumor has it a 3L 80m was 
built with them for full band coverage.

Originally, mostly used for tuning/loading verticals.  No sliding 
contacts makes it quiet and reliable.  I used an MFJ screwdriver control 
with 10 pushbutton 50KHz spaced presets for 80m but now have a RT21dc 
automatically tracking frequency to preset coil positions.  GHeverywhere 
does the mapping.

Grant KZ1W

On 9/14/2021 12:54, Mark - N5OT wrote:
> Wait.  There's such a thing as an "accodion inductor"?  I thought I knew 
> everything.
> 
> I'll be glad when mowing season is over, too.
> 
> 73 - Mark N5OT
> 
> 
> On 9/14/2021 2:44 PM, W3HKK at roadrunner.com wrote:
>> Been reading the encouraging posts. So, I got up and heard good
>> activity, working:
>> VK3HJ - ZL1AZ - VK2WR at Ohio SR and up to 20 minutes after, when the
>> band faded out.
>>
>> Gud to hear Luke, Dennis and Adrian coming through so well, through
>> moderate QRN. Unusually warm temps here for mid Sep. ( 85-88F) I took
>> an hour last week to tweak the 52' tall 1/4 wave INV-L. All 26 radials
>> are still coiled up and hanging from the walnut tree, until lawn
>> mowing season ends in mid Oct. Then I will uncurl them and retune
>> accordion inductor.
>>
>> Heard AA1K this morning as well.
>>
>>
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