Cable Xperts (www.cablexperts.com) has a decent selection of teflon coax - and
will sell you what you need.
I have also noted roll ends of various and sundry teflon coax on E-bay, select
business and industrial on the browse page, then wire and cable. The price per
foot is less heart stopping - but you may have to buy more than you need.
And on the subject at hand I have toasted a few cores in my day, and they
always either recovered nicely or shattered. If you are going to use a ferrite
current balun with more than a barefoot rig put it where serious overheating
won't set something on fire. Especially your house!!!
And finally, it seems the original question on this thread had to do with why a
voltage balun didn't keep RF off the coax shield. Mainly because a voltage
balun is more of an impedance matching transformer than a current blocking
device.
There is still no such thing as a perfectly balanced matching transformer so
some RF winds up on the outside of the coax shield where we don't want it. A
voltage balun at a beam's driven element immediately backed with a current
balun makes a noticible difference in the beam's F/B - especially when W6 is
from 140 to 220 degrees from the DX! That's most of the time in Mississippi.
73 Pete Allen AC5E
> Where can a person buy something like a Teflon insulated RG-8X for high
> power hf?
>
> Tnx,
>
> Van N5HTY
>
>
>
> -------Original Message-------
>
>
>
> From: tentec@contesting.com
>
> Date: 03/31/04 08:33:42
>
> To: tentec@contesting.com
>
> Subject: Re: [TenTec] Re: Toasting those cores....
>
>
>
> "Manuel R. Alonso" wrote:
>
>
>
> > I ORDERED THEIR TYPE "K" MATERIAL BECAUSE
>
> > SHE SAID THAT IS WHAT THEY USE ON THE W2FMI BALUNS THAT THEY SELL. IS TYPE
>
> > "K" MATERIAL THE RIGHT ONE, OR SHOULD I USE TYPE 43 OR 77?
>
>
>
> "K" is an excellent choice, stick to it.
>
>
>
>
>
> > I AM GOING TO WIND TWO (BIFFILAR) #12 ENAMEL INSULATED WIRES ABOUT 12
> TIMES AROUND THE
>
> > CORE.
>
>
>
> That makes a transmission line with a characteristic
>
> impedance substantially higher than 50 Ohms. You may
>
> wish to use a regular 50 Ohms coax, with Teflon
>
> insulation for high power. Up to 1 kW RG58 will do,
>
> or even Rg174 up to few hundred Watts.
>
>
>
> Be sure to apply full power ONLY when the load is
>
> known to be ~50 Ohms resistive, i.e SWR is below 3.
>
>
>
>
>
> 73,
>
>
>
> Sinisa YT1NT, VA3TTN
>
> _______________________________________________
>
> TenTec mailing list
>
> TenTec@contesting.com
>
> http://lists.contesting.com/mailman/listinfo/tentec
>
>
>
> .
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