HF Antenna Whip

Submitted: Thursday, Feb 05, 2004 at 18:44
ThreadID: 10299 Views:2161 Replies:9 FollowUps:19
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Looking for aHF Antenna manufacturer in Adelaide. Need a multi tap whip aerial for my old Codan HF. Have searched ther net in vain and Codan website only talks about advanced multi-tune antennas.

Any ideas?

Cheers,

Willem1958 Patrol Pretty flash eh?
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Reply By: Member - Bernie. (Vic) - Thursday, Feb 05, 2004 at 19:28

Thursday, Feb 05, 2004 at 19:28
Hi Willem
Not sure about Adelaide but if you leave the exact details of what you want
I could give "Telstat" a call & see what they know.

CheersPrado TD Auto
AnswerID: 45587

Follow Up By: Willem - Thursday, Feb 05, 2004 at 21:24

Thursday, Feb 05, 2004 at 21:24
Bernie,

My set has the following channels 2020, 4010, 5145, 5410 6845, 6890, 6950 and 6965.

I busted my last Terlin out bush a while back and then bought one at a garage sale but it only has 2020 and Alice Springs channles.

Thanks for you offer of help.

Cheers,

Willem1958 Patrol Pretty flash eh?
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FollowupID: 307682

Reply By: Mad Dog Morgan (Geelong) - Thursday, Feb 05, 2004 at 19:45

Thursday, Feb 05, 2004 at 19:45
Willem, if you require a whip with the vks737 freq's I can put you on to something that is far below usual retail prices which are as you probably already know outta this world. Email me, I cannot give details here as the manufacturer does not want too much business. BEAM ME UP SCOTTY


Hooroo
Ray
AnswerID: 45589

Follow Up By: Member - Mike (SA) - Thursday, Feb 05, 2004 at 20:25

Thursday, Feb 05, 2004 at 20:25
If that fails - I have a contact in Adelaide who may e able to help. No guarantee. Mad Dog Morgan' deal sounds great.
MikeToo little time in the bush!
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FollowupID: 307672

Follow Up By: Willem - Thursday, Feb 05, 2004 at 21:27

Thursday, Feb 05, 2004 at 21:27
G'day Ray,

Thanks will do.

Cheers,

Willem 1958 Patrol Pretty flash eh?
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FollowupID: 307683

Follow Up By: Mad Dog Morgan (Geelong) - Thursday, Feb 05, 2004 at 21:43

Thursday, Feb 05, 2004 at 21:43
Ok Willem, I'll collect my mail when I get home from work. We are not allowed to access yahoo mail from here. They are very well made whips and resonate very well. I have one which covers all amateur bands plus all vks737 freqs. They also include the 27meg cb band on the vks737 model. Oh by the way, they're from Melb but you'll save yourself a bundle compared with a Terlin believe me. BEAM ME UP SCOTTY


Hooroo
Ray
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FollowupID: 307687

Reply By: Member - Bob - Thursday, Feb 05, 2004 at 20:34

Thursday, Feb 05, 2004 at 20:34
Willem,
Terlin Outbacker in Perth make 'em and post 'em.
http://www.outbacker.com.au/Bob
AnswerID: 45597

Follow Up By: joc45 - Thursday, Feb 05, 2004 at 21:05

Thursday, Feb 05, 2004 at 21:05
And to save the cost of custom-made, they have a couple of ready-made models which include most-used VKS-737 and RFDS channels, reducing the cost.
Gerry
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FollowupID: 307677

Follow Up By: Willem - Thursday, Feb 05, 2004 at 21:47

Thursday, Feb 05, 2004 at 21:47
Thanks Bob....I looked in their ebsite but nothing is opening tonight. Will try again tomorrow.

Cheers,

Willem1958 Patrol Pretty flash eh?
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FollowupID: 307688

Reply By: Member - Frank - Thursday, Feb 05, 2004 at 21:03

Thursday, Feb 05, 2004 at 21:03
try electric bug or wait for the camping show only couple weeks (25)

frankCBS
Cant Bl**dy Sitstill
AnswerID: 45605

Follow Up By: Willem - Thursday, Feb 05, 2004 at 21:57

Thursday, Feb 05, 2004 at 21:57
Frank...I went in to Electric Bug website but it is useless to navigate. Don't know if I am going to make the camping show this time. Apart from the aerial there is not much I need.

Cheers,

Willem1958 Patrol Pretty flash eh?
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FollowupID: 307691

Reply By: Mixo - Thursday, Feb 05, 2004 at 21:32

Thursday, Feb 05, 2004 at 21:32
Willem....... seeing you don't have any VKS737 frequencies built in, was wondering if you do any comms while mobile or just use the radio as a backup in case of drama. Pro multitap antennas are not cheap - pity to have one made without the VKS737 taps. If you only need an emergency backup, can advise on the use of straight wires running off the top of the spring mount - just run one of length suitable for the frequ in use out to an elevated tree branch or similar and you are sure to exceed any tap antenna performance. The tap is for practical convenience - the wire is for performance.....some autotunes can't even keep up with the taps I'm told !The car, the boat, the camper, the radios - is that all there is to life ?
AnswerID: 45606

Follow Up By: Willem - Thursday, Feb 05, 2004 at 21:54

Thursday, Feb 05, 2004 at 21:54
Mixo........Yeah I only use it for emergencies which luckily are few and far between. I have an old 25watt 6924 Codan OPR and I also have the wire aerial. Had the set overhauled recently and a few extra channels put in. How does one measure the wire length of the frequency? Say 4010....

Cheers,

Willem1958 Patrol Pretty flash eh?
0
FollowupID: 307690

Follow Up By: Greg Harewood - Thursday, Feb 05, 2004 at 22:57

Thursday, Feb 05, 2004 at 22:57
Willem - formulae for 1/4 wave sloping wire antenna is 71250/frequency (kHz)..so wire require for 4010 would be 71250/4010=17.77metres...complete list for your set...

Freq Length Wire in metres (1/4 wave)
2020 35.27
4010 17.77
5145 13.85
5410 13.17
6845 10.41
6890 10.34
6950 10.25
6965 10.23

Last 4 freq's would probabaly work OK with 10.30m (say) of wire.

Cheers
Greg
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FollowupID: 307704

Follow Up By: Willem - Thursday, Feb 05, 2004 at 23:11

Thursday, Feb 05, 2004 at 23:11
Many thanks Greg...now what does 1/4 wave sloping wire look like.....I have a normal red coated thin wire which came with the set...must be the right one.

Cheers,

Willem
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FollowupID: 307705

Follow Up By: Mad Dog Morgan (Geelong) - Thursday, Feb 05, 2004 at 23:33

Thursday, Feb 05, 2004 at 23:33
You can use any wire Willem. the sloping part refers to the angle of the antenna. Slope it from the antenna base up to a tree somewhere. Use and old fashioned egg type insulator or a bit of lexen or similiar with a coupla holes in it or a stick to tie the other end of the wire too, tie some string to the insulator. Tie a weight to the string and throw or use some mechanical means to get it over a tree branch. Hoist up the antenna.
Clear as mud eh! no probs, we can go through it at Little Desert. BEAM ME UP SCOTTY


Hooroo
Ray
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FollowupID: 307707

Follow Up By: Greg Harewood - Friday, Feb 06, 2004 at 00:23

Friday, Feb 06, 2004 at 00:23
...yep ...just reminded me..make sure if using insulators to cut wire a tad longer..not sure how important a cm either way is as I have noticed my "spare antenna" works fine on frequencies ~150khz out.. More useless info...most effective wire antenna is angled aprox 45° to the ground and broadside to base station (get the GPS/compass out). (one end in a tree (for example), other end (remove small bit of insulation) jammed in spring base with whip antenna removed. If you happen to be where there are no trees (eg QLD in a few years:) lay it on the ground with end pointing towards station you are calling (if you happen to know) for best results.

Anyone have the GPS coords of RFDS/A4WDRN stations?

Cheers
Greg

Re 1/4 wave: think it means wire lenght is 1/4 of actual amplitude (height) of radio wave.
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FollowupID: 307709

Follow Up By: Mad Dog Morgan (Geelong) - Friday, Feb 06, 2004 at 00:59

Friday, Feb 06, 2004 at 00:59
Without a SWR meter to measure antenna resonance this measurement really only gets us in the ball park. There are many factors that influence resonance such as proximity to objects and height above ground and for fine tuning a meter is required, one cm wont make much difference at these lows freqs but will be critical at UHF. The 1/4 wave is a fraction of the wave LENGTH BEAM ME UP SCOTTY


Hooroo
Ray
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FollowupID: 307711

Follow Up By: Greg Harewood - Friday, Feb 06, 2004 at 02:34

Friday, Feb 06, 2004 at 02:34
..new it was 1/4 of something:)
Over and Out
Cheers
Greg
W138
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FollowupID: 307712

Follow Up By: Mad Dog Morgan (Geelong) - Sunday, Feb 08, 2004 at 06:30

Sunday, Feb 08, 2004 at 06:30
Greg, Try the ACA search engine. You can search on different criteria and lat/lon are returned.

Hmm, they appear to be down at the moment

http://www.aca.gov.au/pls/radcom/register_search.main_page BEAM ME UP SCOTTY


Hooroo
Ray
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FollowupID: 307815

Follow Up By: Mad Dog Morgan (Geelong) - Sunday, Feb 08, 2004 at 18:05

Sunday, Feb 08, 2004 at 18:05
Greg, the engine is up now. I searched on "sites" and "rfds"
All the rfds sites were returned, click on the licence to reveal the lat/lon BEAM ME UP SCOTTY


Hooroo
Ray
0
FollowupID: 307866

Reply By: Phil G - Thursday, Feb 05, 2004 at 21:41

Thursday, Feb 05, 2004 at 21:41
Willem,

Go for Johnson Electronics Midway Rd Elizabeth East Ph 82871061.

thats Steve Johnson, boss of VKS737.

AnswerID: 45609

Follow Up By: Willem - Thursday, Feb 05, 2004 at 22:01

Thursday, Feb 05, 2004 at 22:01
Thanks Phil...will give them a call tomorrow. I don't think that my set has a VKS frequency built in unless I can access them through my other channels.

Cheers,

Willem1958 Patrol Pretty flash eh?
0
FollowupID: 307693

Reply By: Mixo - Friday, Feb 06, 2004 at 09:42

Friday, Feb 06, 2004 at 09:42
Great to see such an outpouring of quality feedback eh Willem ? The Bug people here in the smoke sell a telescopic antenna that goes straight up for 10m ! It drags a bit wire inside toward the heavens of course. As feedback here suggests, you can manually do the same with your bit of wire. Horizontal alignment can be very effective....vertical is good....it might just be that 45 degrees AWAY from the direction that your intended corresponding radio is, is best ! (send your signal off the wire at 90 degrees up to the radio god in the sky and down in the direction of your correspondent. All you need is the tree in the right spot...but horizontal can be good as mentioned. I use [ 300120 / frequency value inMhz= mm ] as my calc for thefullwavelength of the frequency being worked on. 9353mm seems to look after the main VKS737 channel being 8.022 Megs. Most boffins suggest / 4 to make a quarter wave antenna, because it is more manageable and about 95% efficient compared to the whole length. With the above formula, I made a stumpy stainless antenna for my UHF at 157mm. Good for around town and close order work in hilly terrain. Whatever....we must all tinker.The car, the boat, the camper, the radios - is that all there is to life ?
AnswerID: 45658

Follow Up By: Mad Dog Morgan (Geelong) - Friday, Feb 06, 2004 at 11:10

Friday, Feb 06, 2004 at 11:10
I like the formula above better Mixo.
Using your formula you don't find your antennas are a bit long ?
300000 is the speed of light in a free space but radio waves travel a bit slower through a wire but your formula goes the other way, makes the antenna longer. Anyway never mind, as you say..tinker BEAM ME UP SCOTTY


Hooroo
Ray
0
FollowupID: 307728

Follow Up By: Willem - Friday, Feb 06, 2004 at 12:17

Friday, Feb 06, 2004 at 12:17
Thanks everyone for your valuable feedback.

I have my whip aerial mounted on the roofbars at the rear of the truck and as mentioned before I have taps for 2020 and Alice Springs. Will cut some wires to size for the other channels and hook them up on the aerial or horizontal if necessary. I have actually used the wire laid down on a dune pointing in the direction I wanted to communicate with and spoke to Meekatharra, about 500km away. This was on the Canning when I thought that I might run out of fuel (we made it to Well 23 with 9 litres left in the tank!).

I am still mulling over buying a newer radio set with all the VKS channels but there is no room left inside the truck and I will have to look outside the square as to where to put it. PLus thatys a couple of grand I could spend on fuel going somewhere.

Cheers,

Willem

Willem
Out on the Gibber
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FollowupID: 307736

Reply By: Mixo - Friday, Feb 06, 2004 at 11:22

Friday, Feb 06, 2004 at 11:22
Indeed Mad......got my formula from somewhere but I'm just a self taught hacker. Bit of HS science - bit of bush knowledge..... will note the other calc and do some
workings. Regs.The car, the boat, the camper, the radios - is that all there is to life ?
AnswerID: 45675

Reply By: Mixo - Friday, Feb 06, 2004 at 13:13

Friday, Feb 06, 2004 at 13:13
With your needs profile expressed, you might be best to get an 8022 khz crystal (main VKS737 channel) fitted to the current radio and carry on (with a wire). You can easily make a cheap bottom loaded, singe frequency stainless whip too - using PVC fittings and some stainless wire - monitor 8022 while mobile. Whatever....its all fun.The car, the boat, the camper, the radios - is that all there is to life ?
AnswerID: 45687

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