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<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>
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<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>
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<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>
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<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>
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> OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
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><br>
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> OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
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> OZAPRS@aprs.net.au <<a href="mailto:OZAPRS@aprs.net.au">mailto:OZAPRS@aprs.net.au</a>><br>
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><br>
><br>
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><br>
><br>
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><br>
><br>
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