Topband: Air Wound Coil

[Brian Pease]

I used #10 plastic insulated solid "house wire" salvaged from 
2-conductor + ground cable for the small 5 inch dia coil on my 630m 
inverted-L.  The insulation automatically provides a spacing of about 1 
wire diameter and measured Q was 300 at 475kHz.

On 8/30/2018 8:31 AM, David Cutter via Topband wrote:
> If you don't have plastic pipe, select a plastic beaker from the kitchen
> cupboard.
> David G3UNA-G6CP
>
> -----Original Message-----
> From: Topband [mailto:topband-bounces at contesting.com] On Behalf Of Don Kirk
> Sent: 30 August 2018 12:53
> To: Tim Shoppa
> Cc: Trevor; topband
> Subject: Re: Topband: Air Wound Coil
>
> To follow up on what Tim said, I often just use PVC pipe for my coil forms
> and wind my coils using enamel coated wire (16 or 14 gauge enamel coated
> wire), and to keep things simple I often just use close wound turns (no
> space between turns).  With no space between turns the coil loss will not be
> minimized, but compared with most stations ground systems the additional
> coil loss is typically just a small additional loss.
>
> Don (wd8dsb)
>
> On Thu, Aug 30, 2018 at 7:27 AM Tim Shoppa <tshoppa at gmail.com> wrote:
>
>> That is a very nice transmitter tank coil for a kilowatt amplifier.
>> But if you have already calculated or measured the inductance you
>> need, you can just wrap reasonable gauge insulated wire around any
>> cardboard or plastic form you find. I used magnet wire around a
>> cardboard tube. You can see a picture of the coil I wound for my 160M
>> antenna match here, along with some other more complicated link
>> coupled tuners:  http://n3qe.org/tuners.html
>>
>> Tim N3QE
>>
>>> On Aug 30, 2018, at 2:44 AM, MR TREVOR DUNNE <ei2glb at eircom.net> wrote:
>>>
>>> Hi All
>>>
>>> I'm looking for an Air wondering coil like in this link,
>>>
>>> http://www.mfjenterprises.com/Product.php?productid=404-0669
>>>
>>> I've had one on order from MFJ via a UK company for 4 months now and
>>> no
>> sign of it, I want to build a at matching network for my 160m inverted
>> T using it or something similar,
>>> Can anyone tell me where I can get one of these or similar that is
>>> in
>> stock today,
>>> I don't have access to the tools/parts to wind one my self,
>>>
>>> Thanks
>>> Trevor
>>> EI2GLB
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