[Lowfer] New vertical Y antenna

Bill Ashlock ashlockw at hotmail.com
Mon Dec 19 20:52:39 EST 2011 

Rick,

The antenna current calculates to about 316 ma using P = 1 = I^2 R  where R =10.  I left my current meter in Andover so I won't be able to confirm this for about 5 days. When I change over to the larger coil (Rac = 2.5) we'll see a 7.5 ohm total Rac for the antenna. The lighter test coil with the Rac of 5 is hanging on the vertical wire (the actual antenna) near the bottom and is supported by the upper "Y". A planned experiment is to place it in the middle of the vertical wire and see how much the antenna's radiation improves.

Bill

> From: smokinggun at verizon.net
> To: lowfer at mailman.qth.net
> Date: Tue, 20 Dec 2011 01:32:51 +0000
> Subject: Re: [Lowfer] New vertical Y antenna
> 
> Bill,
>    5 OHMS !!
>  Sounds like all that wire you put in the air worked out  and better than 
> you expected; im guessing. How much current are you seeing into the antenna?
>  I will shut down PBO for the next few days and have a look!I will get you 
> some catures when I can.
> 
>  Good luck !
> 
>          Rick
> 
> 
> ----- Original Message ----- 
> From: "Bill Ashlock" <ashlockw at hotmail.com>
> To: <lowfer at mailman.qth.net>
> Sent: Tuesday, December 20, 2011 00:35
> Subject: Re: [Lowfer] New vertical Y antenna
> 
> 
> >
> > Rick and group,
> >
> > I finally loaded up the antenna just before dark tonight after finding yet 
> > another bad connection in the RG-6 cable (now over 250ft long in order to 
> > reach the final at the base of the antenna). I'm seeing just about a watt 
> > of DC input power to the xmitter when I resonate the antenna by varying 
> > the exciter's frequency inside the shack. With a reduction of 11 to 4 in 
> > the transmitter's output transformer (Vcc = 22v), and with a little math, 
> > that works out to an Rac total of approx 10 ohms. I'm using a 'test' 
> > loading coil having an Rac of 5 ohms so the antenna itself has a loss of 
> > only 5 ohms!
> >
> > Should be able to make the final tune-up of the loading coil at 185.300 in 
> > the AM tomorrow... so look for my usual "Wm"s .
> >
> > Bill
> >
> > From: ashlockw at hotmail.com
> > To: lowfer at mailman.qth.net
> > Subject: RE: [Lowfer] New vertical Y antenna
> > Date: Thu, 15 Dec 2011 14:17:07 -0500
> >
> >
> >
> >
> >
> >
> >
> > Hi Rick,
> >
> > Yah, the progress has been good because the weather has been above normal 
> > lately... and almost no snow. Today, however, is the exception with 
> > freezing rain. I'm working inside modifying the one Xmitter I have up 
> > here, so it will drive a vertical. I'm starting with a 10 to 4 step-down 
> > ratio on the output transformer. That's figuring approx 10 ohm Rac total 
> > for the whole antenna (coil + gnd loss). The temporary loading coil I'm 
> > using has #18ga (equiv) Litz on it but the final, heavier, one has #12ga 
> > (equiv) Litz and wound interwoven for very low loss.
> >
> > Looking forward to receiving a return picture of the signal!
> >
> > Bill
> >
> >> From: smokinggun at verizon.net
> >> To: lowfer at mailman.qth.net
> >> Date: Thu, 15 Dec 2011 02:45:34 +0000
> >> Subject: Re: [Lowfer] New vertical Y antenna
> >>
> >> Bill,
> >>  Wow you work fast! Thats a lot of wire to put up in that short time. I
> >> cant wait to see the results. I think I still have a capture or 2 from 
> >> last
> >> season  and my receive setup hasnt changed.
> >>  Of course once you perfect the new antenna , I will bombard you with
> >> questions. Not that Im giving up the loop anytime soon.Its working too 
> >> well
> >> for me right now.
> >> BTW; thanks for the "Y" formula..
> >>
> >>               Rick
> >>
> >>
> >>
> >>
> >>
> >> ----- Original Message ----- 
> >> From: "Bill Ashlock" <ashlockw at hotmail.com>
> >> To: <lowfer at mailman.qth.net>
> >> Sent: Wednesday, December 14, 2011 1:36 AM
> >> Subject: [Lowfer] New vertical Y antenna
> >>
> >>
> >> >
> >> > Rick and others,
> >> >
> >> > I'm all set to begin on-air testing of this new antenna once I install 
> >> > the
> >> > loading coil and transmitter at the base and run wires to it. The 
> >> > capacity
> >> > measurements between upper and lower "Ys" (plus fill-in wires) are
> >> > complete and I'm seeing approx 400pf between them. This makes for a low
> >> > Rac in the loading coil because of the relatively low inductance of 
> >> > 185mh
> >> > at 185.3KHz.
> >> >
> >> > Turned out there was quite a large-sized finge field from the top "Y" 
> >> > and
> >> > I had to expand the lower "Y" in order to capture a good percentage of 
> >> > it.
> >> > That rule of thumb saying the radius of the ground radials must be at
> >> > least equal to the height of the antenna proved to be true, BUT I think
> >> > this applies to a vertical WITHOUT top hat. When a top hat is used it
> >> > appears the radius must be equal to the antenna height PLUS the radius 
> >> > of
> >> > the top hat. At any rate it will be interesting to see how the total 
> >> > Rac
> >> > for this antenna comes out when I apply power, but I suspect it will be
> >> > very low if I have captured as much of the fringe field as capacity
> >> > measurements indicate. BTW there's a formula I found for the capacity
> >> > between two circular conductive planes separated by a large distance 
> >> > (like
> >> > 50ft) that seems to work. For Lowfer antennas it comes out approx 3 
> >> > times
> >> > the capacity derived from the formula that is typically given in text
> >> > books for closely spaced planes not accounting for th
> >> > e fringe field off to the side. It's a bit lengthy but if anyone is
> >> > interested, I'll post it.
> >> >
> >> > Bill
> >> >
> >> >
> >> >
> >> > ______________________________________________________________
> >> > Lowfer mailing list
> >> > Home: http://mailman.qth.net/mailman/listinfo/lowfer
> >> > Help: http://mailman.qth.net/mmfaq.htm
> >> > Post: mailto:Lowfer at mailman.qth.net
> >> >
> >> > This list hosted by: http://www.qsl.net
> >> > Please help support this email list: http://www.qsl.net/donate.html
> >> >
> >> >
> >> > -----
> >> > No virus found in this message.
> >> > Checked by AVG - www.avg.com
> >> > Version: 2012.0.1873 / Virus Database: 2108/4678 - Release Date: 
> >> > 12/13/11
> >> >
> >>
> >> ______________________________________________________________
> >> Lowfer mailing list
> >> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> >> Help: http://mailman.qth.net/mmfaq.htm
> >> Post: mailto:Lowfer at mailman.qth.net
> >>
> >> This list hosted by: http://www.qsl.net
> >> Please help support this email list: http://www.qsl.net/donate.html
> >
> > ______________________________________________________________
> > Lowfer mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/lowfer
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:Lowfer at mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> >
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2012.0.1890 / Virus Database: 2108/4690 - Release Date: 12/19/11
> > 
> 
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

More information about the Lowfer mailing list