[pskmail] DK9SQ Comments

  • From: "Bill - N8ET" <n8et@xxxxxxxxxx>
  • To: sv1uy <sv1uy@xxxxxxxxxxx>, pskmail@xxxxxxxxxxxxx
  • Date: Mon, 09 Apr 2007 12:37:52 -0400

Hi - 

I have to respond to this one even though my responsey does not have 
much to do with PSKmail.....

I sell the DK9SQ masts and products in the US. Several years ago someone 
in the US claimed the mast was conductive and RF lossy.  I ran some tests 
and was unable to duplicate the claims.  None of the masts I have sold or 
tested have ever been conductive.  They are made of fiberglass, and are an 
insulator.  I have tested with an ohm meter and found no conductivity.  
Pieces have been put in a microwave oven with no heating effects observed.  
I have run tests on a 33' vertical wire with an antenna analyzer - first 
suspended without the DK9SQ mast, and then moving the mast closer, and 
finally wrapping the wire around the mast while looking for changes on the 
analyzer at the base of the antenna.  I had to wrap the wire around the mast 
about 6  times before I noticed any change at all in the impedance at the 
base. The change was very minor, and I attribute it to the increasing 
inductance in the wire as it was wound around the mast.

> On Mon, 09 Apr 2007 13:32:21 +0200, Per Crusefalk wrote
> > Hi Walt,
> > 
> > That sounds like an interesting setup. The only problem I see with 
> > it is transporting all those pipes. I will go to the hardware store 
> > and see if there is any telescoping support that I can use. I know 
> > they have long telescoping handles for garden saws (for cutting 
> > branches high up in trees) and I may find something usable there. 
> > I'll have a look at PVC pipes as well while I'm there (I made the 
> > T2FD spreaders from 1" pipes).
> > 
> > 73 de Per, sm0rwo
> 
> Hi Per,
> 
> You could also buy a 6 - 9 meter fiberglass fishing pole and support the top
> of your dipole as high as 5 or 8 meters depending on the pole you buy. These
> pole cost around 20 EUROS in my country. There is also a nice 10 meter fishing
> pole made from DK9SQ (I have 2 of them on for a 1 ELEMENT 40 - 10 meter QUAD
> and the other for a dipole), but this is reinforced with graphite and it is
> somehow conductive hence you cannot use it for a vertical wire wrapped around
> it a few times a huge vertical coil. 
> 
> Now you can easily make an 80 - 10 meters dipole using 22 meters loudspeaker
> wire (the cooper could be as small as 1mm - 1.5mm thick) by separating 13.4
> meters to form the dipole leaving the unseparated 8.8 meters as a 75 OHM
> twinlead as a feeder (instead of open wire). You could tie the dipole at about
> 7 meters from the bottom of the fishing pole with 2 cable ties, in order to
> make a 26.8 meters long INVERTED V. Of course you would need an ATU. A small L
> type would have no problem in tuning this antenna in all bands from 80 - 10
> meters and I imagine it would also tune on 160 although I have never tried it
> on 160.
> 
> My favourite is a half version of that using 15.5 meters of loudspeaker wire
> separating 6.7 meters and using 8.8 as a feeder tied as far near the top of a
> 5 meter fishing pole so it does not bend very much at the top and using it as
> a 40 - 10 meters INVERTED Vee Dipole when I go mountain trekking with my
> FT-817 and a Z-match ATU. The fishing pole is less than 50cm when collapsed
> and it all fits in my backpack. It is a very light antenna setup and it takes
> only 5 minutes to erect. 
> 
> Of course if you feel that the losses of the 8.8 feeder using loudspeaker wire
> are unacceptable (I am that bothered) you could always replace it with 300 or
> 450 OHM open wire but it is heavier. I have tried 300 OHMs (slotted open wire)
> and it is not that heavy. Perhaps this is a better solution.
> 
> Finally you can support a 10 meter wire making a vertical antenna with one
> elevated radial using open wire at the bottom of the antenna and using a
> simple ATU again to tune it to most HF bands bands, probably 80 - 10 meters
> but if the ATU can take it you could also use it on 160 provided you use a
> longer radial bend around, but the secret is to have it elevated. Thsi setup
> is good for DX.
> 
> Good luck with your antenna projects.
> 
> Don't forget that if there isn't any DX you can always go fishing! hi hi hi!!!
> 
> ---
> 73 de Demetre Valaris - SV1UY
> e-mail: sv1uy@xxxxxxxxxxx
> AX25 PBBS: SV1UY@xxxxxxxxxxxxxxxx
> http://sv1uy.ampr.org/~sv1uy
> http://www.athnet.ampr.org/~sv1uy
> 
> 
> 
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> 

-- 
73 - Bill - N8ET
Kanga US
www.kangaus.com
419-423-4604 (Kanga)
419-423-5643 (home)


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