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10-08-2019, 00:17
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#16
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by Jim Cate
And Matt, after sending out your emergency message via squid pole antenna, you can do some emergency fishing/squid jigging with it while awaiting an answer!
And FYI, when we were dismasted I draped a random length of hookup wire from the backstay chainplate (where I fed my no-insulator light it all up rig) to what was left of the bow pulpit (the highest remaining bit on the boat) and checked into the Comedy net as usual, mentioning casually what had happened. Bad idea! They all wanted to come rescue us, and we didn't need or want rescuing. But anyway, it worked pretty well and cost nothing... my kinda deal!
Jim
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Jim, you know my theory on your radio transmission system. I've commented before, using Ann as an antenna just seems wrong to me.
BTW, nice time you made heading North. I turned my back on Marine traffic for a minute and you did some kind of Warp 5 thing up the coast.
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Refitting… again.
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10-08-2019, 01:17
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#17
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Registered User
Join Date: Aug 2013
Location: Back in Montt.
Boat: Westerly Sealord
Posts: 8,180
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Re: DIY HF whip
Quote:
Originally Posted by GILow
I am not sure my boat will ever look "cool". No matter how many antennas.
But yeah, the Aerogen 6 could chew through quite a bit before it surrendered. If my HF theory is ok, the lower frequencies are the ones I will want in a coastal emergency, and the higher frequencies if I am way off shore?
Maybe one of each squid pole. Seriously, I have been staring at AU$900 antennas for so long now that the thought of spending AU$80 for a pair plus a few $ for the wire is very appealing.
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Have you read the manual by any chance? 6 metre squid pole with one metre tail to tuner = 7 metres....
I can't imagine you ever wanting to go below 40 metres/ 7 megs...
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10-08-2019, 02:01
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#18
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by El Pinguino
Have you read the manual by any chance? 6 metre squid pole with one metre tail to tuner = 7 metres....
I can't imagine you ever wanting to go below 40 metres/ 7 megs...
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What is the "manual" you talk of? What strange mythical creature?
Yeah... um... right. Probably SHOULD have read the manual, now that you mention it.
6m squid pole coming up!
Thank you E.P.
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10-08-2019, 02:34
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#19
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by El Pinguino
I can't imagine you ever wanting to go below 40 metres/ 7 megs...
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Actually....
So I am looking at my little HF cheat sheet, and it is telling me:
<300 km 3 - 4 MHz day and 2 - 4 MHz night
300 to 750 km 4 - 6 MHz day and 3 - 7 MHz night.
750 - 1500 km 5 - 9 MHz day and 6 - 10 MHz night.
1500 - 2500 km 8 - 12 MHz day and 7 - 11 MHz night
2500 - 5000 km 10 -18 MHz day and 8 - 15 MHz night
I'm thinking off shore cruising, East Coast of Australia, and waddaya know, Charleville is 700 km inland, so yes, that means basically 5 - 9 MHz minimum.
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10-08-2019, 02:58
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#20
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Registered User
Join Date: Aug 2013
Location: Back in Montt.
Boat: Westerly Sealord
Posts: 8,180
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Re: DIY HF whip
Quote:
Originally Posted by GILow
What is the "manual" you talk of? What strange mythical creature?
Yeah... um... right. Probably SHOULD have read the manual, now that you mention it.
6m squid pole coming up!
Thank you E.P.
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De nada.
Manual is a very nowledgeable smart Chilean mate of mine....
I think Charleville put out a daily propagation chart in their fax schedule...
Query.... memory fade here.. what radio do you have...?
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10-08-2019, 03:02
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#21
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by El Pinguino
De nada.
Manual is a very nowledgeable smart Chilean mate of mine....
I think Charleville put out a daily propagation chart in their fax schedule...
Query.... memory fade here.. what radio do you have...?
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Icom 802 with the AT-130 ATU.
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10-08-2019, 03:04
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#22
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Registered User
Join Date: Aug 2013
Location: Back in Montt.
Boat: Westerly Sealord
Posts: 8,180
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Re: DIY HF whip
0100Z and 0131Z.... VMC & VMW Radio Fax Schedule
Is allowed to speak to Wiluna or Taupo as well ...... did you read Jeannes comments on her blog re HF and the yacht Water Music the other day?
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10-08-2019, 03:05
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#23
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Registered User
Join Date: Aug 2013
Location: Back in Montt.
Boat: Westerly Sealord
Posts: 8,180
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Re: DIY HF whip
Quote:
Originally Posted by GILow
Icom 802 with the AT-130 ATU.
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802!.... Golly......
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10-08-2019, 03:57
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#24
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by El Pinguino
802!.... Golly......
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Yes. Lots of shiny buttons.
No bl—dy idea how to drive it TBH.
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10-08-2019, 03:58
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#25
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by El Pinguino
did you read Jeannes comments on her blog re HF and the yacht Water Music the other day?
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Not yet. I will have a look.
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10-08-2019, 05:26
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#26
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Moderator
Join Date: Jan 2010
Location: Minnesota
Boat: Tartan 3800
Posts: 4,808
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Re: DIY HF whip
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10-08-2019, 05:49
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#27
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Registered User
Join Date: Sep 2008
Location: On the boat, somewhere in Australia.
Boat: Swanson 42 & Kelly Peterson 44
Posts: 9,127
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Re: DIY HF whip
Quote:
Originally Posted by Jammer
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My goodness, if that is what you use for an antenna I really suggest you don't go too far from shore.
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10-08-2019, 11:04
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#28
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Registered User
Join Date: Nov 2018
Location: Panama
Boat: Norseman 447
Posts: 1,626
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Re: DIY HF whip
The last time I saw a broken HF whip antenna, it was nothing more than a fiberglass sleeve with a piece of #14 wire run through it. Anything that is conductive will work. At 23’ long, the tuner should be able to tune any frequency. If it’s shorter, you might have trouble tuning the lowest frequencies. So this is mostly a mechanical and cost problem. Electrically you could use almost anything.
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10-08-2019, 11:13
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#29
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Registered User
Join Date: Oct 2018
Location: Niceville, Florida
Boat: Pacific Seacraft 31
Posts: 45
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Re: DIY HF whip
Jim’s experience shows that an emergency backup antenna doesn’t require storing anything extra on the boat that you wouldn’t have on board anyway.
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10-08-2019, 12:51
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#30
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Registered User
Join Date: Jan 2019
Location: Oceanside Ca
Boat: Lancer 27PS
Posts: 617
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Re: DIY HF whip
OK @GILow, the math is simplistic enough for results. Might not be the best results, but results none the less.
We want to work in 1/4 wavelengths. Even multiples of 1/4 wavelengths is our enemy. So stay away from 2/4, 4/4, 6/4, 8/4, and so on. We know that 468 (150 in meters) is the number for 1/2 wavelengths. Therefore, 234 (75 in meters) is 1/4 wavelength.
With those numbers in mind, we see that at 23' (7.2m) the frequency at 1/4 wave is 10.17 MHz. That is a usable length because it will also work at 1/8 wave, or 5 MHz. So the tuner will tune the 40m band well.
So whatever frequency you want to use, it should be the lowest. If 7MHz is what you want, then 33' will tune nicely. However, you may have issues if you try 20m because 33' is very close to 1/2 wavelength on 20m.
The solution is to pick a frequency outside the band you want to operate on. So pick 6MHz or 8MHz or 9MHz and so on. This will allow your tuner to tune outside the ham bands. If you are dealing with Maritime frequencies you will want to think in the same plane. Some antenna lengths will work almost all bands but there will be some that the tuner will not like.
All this is based solely on my opinion. There may be others that will disagree with me. But it is all good.
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