<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<style type="text/css" style="display:none;"><!-- P {margin-top:0;margin-bottom:0;} --></style>
</head>
<body dir="ltr">
<div id="divtagdefaultwrapper" style="font-size:12pt;color:#000000;font-family:Calibri,Helvetica,sans-serif;" dir="ltr">
<p style="margin-top:0;margin-bottom:0">I did similar with a Codan autotune on my Landcruiser, mounted above the spare wheel carrier connected to my Codan 9323.</p>
<p style="margin-top:0;margin-bottom:0"><br>
</p>
<p style="margin-top:0;margin-bottom:0">Hit the line at the same spot... was waiting for smoke to fill the cabin. I was pleased it didn't, but disappointed as it would have been pretty impressive!<br>
</p>
</div>
<hr style="display:inline-block;width:98%" tabindex="-1">
<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> OZAPRS <ozaprs-bounces@aprs.net.au> on behalf of Glen English VK1XX <glenlist@pacificmedia.com.au><br>
<b>Sent:</b> Friday, 8 December 2017 5:26:29 PM<br>
<b>To:</b> ozaprs@aprs.net.au<br>
<b>Subject:</b> Re: [OZAPRS] On possibilities with short HF whips</font>
<div> </div>
</div>
<div class="BodyFragment"><font size="2"><span style="font-size:10pt;">
<div class="PlainText">what are the recommendations and user practical limits for Melbourne ?
<br>
(trams)<br>
<br>
Canberra here you'll  get into trouble ~ 4m<br>
<br>
I had the loop on my vehicle when I was driving in Melbourne a fair bit....<br>
<br>
I once hit a tram line with my car roof antenna heatshrink insulated <br>
helical at Racecourse Road, Kensington... it made a huge pop in the <br>
receiver but otherwise no damage...<br>
<br>
<br>
<br>
<br>
On 8/12/2017 3:07 PM, Matthew Cook wrote:<br>
> This is also worth considering when looking at larger HF whips.<br>
><br>
> <a href="http://www.rms.nsw.gov.au/business-industry/heavy-vehicles/road-access/restricted-access-vehicles/4-6m-high.html">
http://www.rms.nsw.gov.au/business-industry/heavy-vehicles/road-access/restricted-access-vehicles/4-6m-high.html</a><br>
><br>
> Each state has their own variations to the above, nationally <br>
> un-restricted is 4.3m.<br>
><br>
> 73<br>
><br>
> Matthew<br>
> VK5ZM<br>
><br>
> On 8 December 2017 at 14:03, Graeme <graeme@abrona.com.au <br>
> <<a href="mailto:graeme@abrona.com.au">mailto:graeme@abrona.com.au</a>>> wrote:<br>
><br>
>     Thanks Glen.<br>
><br>
>     Obviously my decision against buying a 2.2m centre loaded 40m whip<br>
>     because it would bend in the wind to its disadvantage in favour of<br>
>     a base loaded 1.4m whip wasn't a good one for multiple reasons.<br>
><br>
>     Graeme 2HFG<br>
><br>
>     -----Original Message----- From: Glen English VK1XX<br>
>     Sent: Friday, December 8, 2017 10:19 AM<br>
>     To: ozaprs@aprs.net.au <<a href="mailto:ozaprs@aprs.net.au">mailto:ozaprs@aprs.net.au</a>><br>
>     Subject: Re: [OZAPRS] On possibilities with short HF whips<br>
><br>
><br>
>     Ran some NR predictions for 10 MHz for Brisbane Sydney, and 7 and 3.5<br>
><br>
>     and also some more details calcs on the Diamond 1.4m logn base<br>
>     loaded whip<br>
><br>
>     turns out to be ~ 3% efficiency.<br>
><br>
>     for the -15dBi TX terminal (1.4m base loaded whip with suboptimal<br>
>     loading Q)<br>
><br>
>     yep,  in daytime, single hop 750-1200km , 100W into the antenna,<br>
>     expect<br>
>     around 15dB SNR for the 300 baud modem given a good receiver<br>
>     antenna and<br>
>     setup...with a modem like DireWolf that can cope with frequency<br>
>     variations. Be sure you know your radio frequency offset before<br>
>     you start.<br>
><br>
>     with same length whip on 7 MHz, expect about 300-700km in<br>
>     daylight, but<br>
>     not much use outside that time and distance.<br>
><br>
>     All of this means is for 300 baud FSK packet mode and 100W, the<br>
>     mode is<br>
>     unsuitable for low efficiency mobile antennas like base loaded short<br>
>     whips. (3% or less efficiency at 10 MHz, 2% at 7 MHz etc)<br>
><br>
>     All this points to: (in my opinion) needing  a >=2.2m long whip<br>
>     instead<br>
>     of a 1.4m long whip.<br>
>     and  an antenna with a non base loaded structure (for 300 baud packet)<br>
><br>
>     Get your antenna efficiency up to 10% at 7 MHz and then now you<br>
>     have an<br>
>     idea setup 24 hours, single freq .... 10 MHz almost good enough except<br>
>     for the wee hours 2am-sunrise when you will be asleep anyway.<br>
><br>
>     So the lesson here, 300 baud packet needs decent antenna efficiencies<br>
>     mobile.<br>
>     hence the need for a mode that does about 6dB better<br>
><br>
>     sure we can do alot better than 6dB, but 6dB better mode is what is<br>
>     required to work on the 1.4m base loaded whips.<br>
><br>
>     Otherwise for 300 baud FSk packet, it needs to be teamed up with<br>
>     antenna<br>
>     efficiency >= 8%, implying  something with a feedpoint of around 2<br>
>     ohms<br>
>     Rr and not too lossy loading and matching... a whip of 2 meters<br>
>     tall  at<br>
>     10 MHz with continuous or 1/3 loaded structure. Base loaded structures<br>
>     are the worst !<br>
><br>
>     The longer 1.8m long CB helical whips are a bit hard to find these<br>
>     days.<br>
><br>
><br>
><br>
><br>
><br>
><br>
><br>
><br>
>     g<br>
><br>
><br>
>     On 7/12/2017 6:36 PM, Glen English VK1XX wrote:<br>
><br>
>         ok<br>
><br>
><br>
>         On 7/12/2017 6:24 PM, vk4tec@tech-software.net<br>
>         <<a href="mailto:vk4tec@tech-software.net">mailto:vk4tec@tech-software.net</a>> wrote:<br>
><br>
>             You are not telling me anything new<br>
><br>
>             -----Original Message-----<br>
>             From: OZAPRS [<a href=""></a>mailto:ozaprs-bounces@aprs.net.au<br>
>             <<a href="mailto:ozaprs-bounces@aprs.net.au">mailto:ozaprs-bounces@aprs.net.au</a>>] On Behalf Of Glen<br>
>             English VK1XX<br>
>             Sent: Thursday, 7 December 2017 5:10 PM<br>
>             To: ozaprs@aprs.net.au <<a href="mailto:ozaprs@aprs.net.au">mailto:ozaprs@aprs.net.au</a>><br>
>             Subject: Re: [OZAPRS] Hf gates CD<br>
><br>
>             base station 700-1500km away will hear you, but you wont<br>
>             hear a station 50km away.<br>
><br>
><br>
>             On 7/12/2017 5:57 PM, vk4tec@tech-software.net<br>
>             <<a href="mailto:vk4tec@tech-software.net">mailto:vk4tec@tech-software.net</a>> wrote:<br>
><br>
>                 Go for a walk<br>
><br>
>                 -----Original Message-----<br>
>                 From: OZAPRS [<a href=""></a>mailto:ozaprs-bounces@aprs.net.au<br>
>                 <<a href="mailto:ozaprs-bounces@aprs.net.au">mailto:ozaprs-bounces@aprs.net.au</a>>] On Behalf Of Glen<br>
>                 English VK1XX<br>
>                 Sent: Thursday, 7 December 2017 4:55 PM<br>
>                 To: ozaprs@aprs.net.au <<a href="mailto:ozaprs@aprs.net.au">mailto:ozaprs@aprs.net.au</a>><br>
>                 Subject: Re: [OZAPRS] Hf gates CD<br>
><br>
>                 tracker might well have CD but:<br>
><br>
>                 1) Consider that in the mobile, you wont hear any<br>
>                 stations less than the skip distance (unless they are<br>
>                 10km away) . The daytime skip distance might be<br>
>                 700km.... so anyone inside that distance you wont<br>
>                 hear  cause the ionosphere wont support it..it wont<br>
>                 support any angles higher than perhaps 45 degrees.<br>
><br>
>                 The base station though will hear lots of<br>
>                 transmissions from lots of stations >700km  to 1500km<br>
>                 away, so there would be significant collision chance<br>
>                 if the position update is too often. Maybe 10 minutes<br>
>                 might be suitable. I dunno why people run..<br>
><br>
>                 2) With a 5%  to 10%  efficiency mobile you wont hear<br>
>                 too much unless the propagation is optimal...<br>
><br>
><br>
>                 glen<br>
><br>
><br>
><br>
><br>
><br>
>                 On 7/12/2017 5:41 PM, vk4tec@tech-software.net<br>
>                 <<a href="mailto:vk4tec@tech-software.net">mailto:vk4tec@tech-software.net</a>> wrote:<br>
><br>
>                     Blind ?<br>
><br>
>                     Tracker has CD<br>
><br>
>                     -----Original Message-----<br>
>                     From: OZAPRS [<a href=""></a>mailto:ozaprs-bounces@aprs.net.au<br>
>                     <<a href="mailto:ozaprs-bounces@aprs.net.au">mailto:ozaprs-bounces@aprs.net.au</a>>] On Behalf Of<br>
>                     Glen English VK1XX<br>
>                     Sent: Thursday, 7 December 2017 2:46 PM<br>
>                     To: ozaprs@aprs.net.au <<a href="mailto:ozaprs@aprs.net.au">mailto:ozaprs@aprs.net.au</a>><br>
>                     Subject: Re: [OZAPRS] Hf gates<br>
><br>
>                     but how does this matter?<br>
><br>
>                     You will  be transmitting on a frequency blind<br>
><br>
>                     there will be receivers you cannot control<br>
><br>
>                     There will be any number of propagation modes you<br>
>                     cannot control...<br>
><br>
><br>
><br>
>                     On 7/12/2017 3:34 PM, Andrew Rich wrote:<br>
><br>
>                         Hi<br>
><br>
>                         Can I get a list of hf gates on 10.147<br>
><br>
>                         In my planning for the Xmas run<br>
><br>
>                         Cheers<br>
><br>
>                     _______________________________________________<br>
>                     OZAPRS mailing list<br>
>                     OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>                     <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">
http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>                     <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
>                     _______________________________________________<br>
>                     OZAPRS mailing list<br>
>                     OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>                     <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">
http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>                     <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
>                 _______________________________________________<br>
>                 OZAPRS mailing list<br>
>                 OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>                 <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>                 <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
>                 _______________________________________________<br>
>                 OZAPRS mailing list<br>
>                 OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>                 <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>                 <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
><br>
>             _______________________________________________<br>
>             OZAPRS mailing list<br>
>             OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>             <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>             <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
>             _______________________________________________<br>
>             OZAPRS mailing list<br>
>             OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>             <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>             <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
><br>
><br>
>         _______________________________________________<br>
>         OZAPRS mailing list<br>
>         OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>         <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>         <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
><br>
><br>
>     _______________________________________________<br>
>     OZAPRS mailing list<br>
>     OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>     <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>     <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
>     _______________________________________________<br>
>     OZAPRS mailing list<br>
>     OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
>     <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
>     <<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a>><br>
><br>
><br>
><br>
><br>
> _______________________________________________<br>
> OZAPRS mailing list<br>
> OZAPRS@aprs.net.au<br>
> <a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
<br>
<br>
_______________________________________________<br>
OZAPRS mailing list<br>
OZAPRS@aprs.net.au<br>
<a href="http://lists.aprs.net.au/mailman/listinfo/ozaprs">http://lists.aprs.net.au/mailman/listinfo/ozaprs</a><br>
</div>
</span></font></div>
</body>
</html>