[Lowfer] Wm beacon testing tonight @ JAY

riese-k3djc at juno.com riese-k3djc at juno.com
Tue Nov 18 21:36:44 EST 2014 

remember the limit ( supposably ) on antennas fer lofers is 50 Ft

Bob K3DJC



On Tue, 18 Nov 2014 17:23:09 -0500 <jrusgrove at comcast.net> writes:
> Charlie
> 
> Haven't looked into conductor size for verticals. I'm sure my 90' 
> vertical height Marconi would do 
> better with a cage instead of the #12 THHN I'm currently using.
> 
> Litz that size is certainly available new but one would pay dearly 
> for it. I picked up several 
> hundred feet a few years back from the LF guys in G land. The radio 
> club dismantled a number of 
> Decca coils with the Litz proceeds going to support the club. Very 
> nice stuff but still not cheap. 
> It's destined for a 137 kHz loading coil ... someday.
> 
> Every dB in 'lowferdom' counts way more than a dB at HF ... that's 
> for sure. Look forward to seeing 
> your beacon again this winter!
> 
> Jay
> 
> 
> ----- Original Message ----- 
> From: "Charlie , W5COV" <cvest at cox.net>
> To: <lowfer at mailman.qth.net>
> Sent: Tuesday, November 18, 2014 4:36 PM
> Subject: Re: [Lowfer] Wm beacon testing tonight @ JAY
> 
> 
> > Jay,
> >
> > Just curious if you have run similar tests on conductors for say a 
> nominally 50 foot vertical ?
> >
> > Also is 1/4" Litz available commercially ? I know it would be 
> expensive, but most of us didn't get 
> > into this hobby because it was cheap. <grin>
> >
> > Just curious if it was commercially available, or if perhaps 
> someone had built their own version 
> > of a Litz type wire conductor. Part 15, even one additional dB can 
> make all of the difference in 
> > the world of being seen or not.
> >
> > Although I know one can get on the air these days with a fairly 
> decent regular ham station by 
> > building or even buying some older gear for under $100.
> >
> > Thanks,
> >
> > Charlie, W5COV
> >
> > On 11/18/2014 12:56 PM, N8OOU wrote:
> >> Jay, Thanks for the operating info gathered from your previous 
> tests. I will take it into 
> >> consideration in my future builds. I don't consider your input a 
> wet blanket, as I have no 
> >> mileposts to judge forward or backward progress.
> >>
> >> Implementing a large transmitting loop here is well within 
> reason, but other less controversial 
> >> designs can easily be accommodated too.  I want the station to 
> operate as close as possible to 
> >> the level of it's previous operator, but it must do so within my 
> comfort level.  That's a major 
> >> component in the beacon testing I am doing now.
> >>
> >>
> >> 73   de   N8OOU - Mike Meek
> >>
> >> On 11/18/2014 09:56 AM, jrusgrove at comcast.net wrote:
> >>> Mike
> >>>
> >>> Dug out my antenna notes on lowfer VD from many years ago. The 
> antenna
> >>> was 200' perimeter. The loop conductor was milspec RG-11 
> (excellent
> >>> braid) using the outer braid as the loop conductor. Since the 
> antenna
> >>> could be raised and lowered with relative ease I also made 
> measurements
> >>> on 200' perimeter loops made from #12 and #8 copper wire to see 
> how they
> >>> performed. Analysis was based on measured antenna current which 
> gives an
> >>> accurate indication of antenna Rtotal. The Rtotals can then be 
> compared
> >>> to predict the dB difference between the antenna conductors. I 
> also made
> >>> some calculations based on other antenna conductors. RG-11 is 
> the
> >>> reference conductor at 0 dB.
> >>>
> >>> 1/4" Litz......................+1.3 dB
> >>> 7/8" Heliax.................+ 0.9 dB
> >>> 1/2" Copper tubing.....+0.4 dB
> >>> RG-11............................0 dB
> >>> #8 Copper.................-2.4 dB
> >>> #12 Copper...............-3.8 dB
> >>>
> >>> You're #16 loop conductor is going to be even further down the 
> list ...
> >>> that plus the fact your antenna area is less than that of a 
> 200'
> >>> perimeter are going to make this a challenge. Keep in mind that 
> on an
> >>> Argo display a 1 dB difference in received signal level can mean 
> the
> >>> difference between barely visible and solid white line 
> reception. Not
> >>> trying to throw a wet blanket on your efforts ... just giving 
> you an
> >>> idea what to expect and what's possible.
> >>>
> >>> Jay W1VD  WD2XNS  WE2XGR/2
> >>>
> >>>
> >>>
> >> ***************** snip ***********************
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