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## Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals

 To: "'Discussion of Ten-Tec Equipment'" Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals "Rick - DJ0IP / NJ0IP" Discussion of Ten-Tec Equipment Thu, 26 Jan 2012 18:06:05 +0100 mailto:tentec@contesting.com>
 ```Steve you are absolutely correct. As I said much earlier in this thread, Joel, W1ZR measured losses of the various openwire antennas and HE EVEN DIPPED THEM IN MUD and measured it again with the entire length covered in mud. The losses did not go up, but the matchbox required a different setting. That's all. This whole thread has been kind of like people arguing the world is flat, after Columbus sailed around it. Yes, I know he didn't actually sail all the way around, but you guys get the point. If we return to the original question posed in this thread, the simple answer is "YES". End of thread. ;-) There is nothing wrong with feeding an elevated groundplane with openwire. It's not a lot different than the vertical dipoles which I have been feeding with openwire of 20 years. 73 Rick -----Original Message----- From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com] On Behalf Of Steve Hunt Sent: Thursday, January 26, 2012 5:52 PM To: Discussion of Ten-Tec Equipment Subject: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals Here's some calculations to support that last comment: Solid dielectric coax Vf=0.66 and foam dielectric coax Vf=0.85, therefore relative dielectric constants must be 2.29 and 1.38 respectively. So, if we keep the coax outer diameter the same, the foam inner conductor must increase by SQRT(2.29/1.38)=1.288; that makes the RF resistance 0.776 times what it was. If we assume a loss of 1.8dB in a particular length of solid dielectric cable, that reduction in RF conductor resistance reduces the losses to 1.5dB - *exactly the quoted figure*. In other words the increased centre conductor diameter and the consequent reduced copper losses *exactly* account for the quoted difference in cable loss; *losses in the dielectric are not a significant factor*. 73, Steve G3TXQ On 26/01/2012 15:57, Steve Hunt wrote: > If you look at the technical data for a Belden solid dielectric RG58 > (say 8259) and compare it with a foam dielectric RG58 (say 7807) you'll > see that the centre conductors are significantly different diameter: > 0.035" vs 0.044" - they have to be to achieve the same 50 Ohm > characteristic impedance with different dielectric materials. > > The difference in loss is almost totally down to the smaller conductor > diameter, not to differences in dielectric loss. > > 73, > Steve G3TXQ > > > On 26/01/2012 13:43, Carl Moreschi wrote: >> Here is some data taken from the ARRL handbook on losses for various >> transmission lines at 14 mhz per 100 feet. >> >> >> RG-58 hard dielectric 1.8 DB >> RG-58 foam dielectric 1.5 DB These two have the same I squared R loss >> >> RG-8 hard dielectric 0.85 DB >> RG-8 foam dielectric 0.6 DB These two have the same I squared R loss >> >> Open wire line air dielectic TV type less then 0.1 DB >> >> As you can see from above, the dielectric has significant meaning to the >> loss. >> >> Carl Moreschi N4PY >> 121 Little Bell Dr. >> Hays, NC 28635 >> www.n4py.com >> >> > _______________________________________________ > TenTec mailing list > TenTec@contesting.com > http://lists.contesting.com/mailman/listinfo/tentec > > _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec _______________________________________________ TenTec mailing list TenTec@contesting.com http://lists.contesting.com/mailman/listinfo/tentec ```
 Current Thread Re: [TenTec] Re. [Ten Tec] Grounds and power grid noise, (continued) Re: [TenTec] Re. [Ten Tec] Grounds and power grid noise, Phil Sussman Re: [TenTec] Re. [Ten Tec] Grounds, Richard Schmidt Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Stuart Rohre Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Jim Brown Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Carl Moreschi Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Jim Brown Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Carl Moreschi Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Carl Moreschi Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Steve Hunt [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Steve Hunt Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Rick - DJ0IP / NJ0IP <= Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Richards Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Jim Brown Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Steve Hunt Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Steve Hunt Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Phil Sussman Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Rick - DJ0IP / NJ0IP Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Jim Brown Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Steve Hunt Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Carl Moreschi Re: [TenTec] Re. [Ten Tec] Grounds and balanced fed verticals, Rick - DJ0IP / NJ0IP