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 The absence of music and crap reception.
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 Return to top of page · Post #: 16 · Written at 1:01:50 AM on 29 January 2020.
GTC's avatar
 GTC
 Location: Sydney, NSW
 Member since 28 January 2011
 Member #: 823
 Postcount: 6689

Hard to beat D10 Field Telephone Cable for strength and durability.


 
 Return to top of page · Post #: 17 · Written at 7:36:47 AM on 29 January 2020.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7307

I am not sure if we are talking about the same thing here but in rural areas and outlying areas of the capital cities, a lot of the old copper network was strung up as aerials rather than being underground and this included the 'last mile'. The cable used was figure 8 but with an added catenary wire built in, so the whole section looked a bit like a clover leaf.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 18 · Written at 10:02:01 AM on 29 January 2020.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5258

The open LV mains wire aerial from 1962 of a round 500m is multi strand (It has a name) Its multi strand, it has copper in it but is definitely a High Tensile alloy. Cold bending it does require some force and a sharp bend would not be a good idea. Joints are "Western Union" and soldered.

Tax deductable farm electric fence stuff is nearly all galvanised. Insulator material is either plastics or ceramic (porcelain) albeit I have some recycled glass ones.

The great thing is the insulator variety. Some can be stood off from the fence, some are feed through and there are the egg type in plastic & porcelain and some can be screwed to wooden posts. Compared to some of the long wire kits I have seen my method is structurally vastly superior and one is at minimum 40 years old. It has been exposed to 162 Kmph wind and survived.

At one point the telephone lines were strung from trees, on property there at one point there were two aerial wires on poles for 600m along the driveway.


 
 Return to top of page · Post #: 19 · Written at 3:50:00 PM on 29 January 2020.
Brad's avatar
 Administrator
 Location: Naremburn, NSW
 Member since 15 November 2005
 Member #: 1
 Postcount: 7307

Marc, the way you have tensioned your aerial is the same as how railway catenaries are tensioned these days. This helps protect them when trees fall on them. Obviously there'd be times when even this doesn't work but it has helped. Recently, widowmakers fell on rail lines at Mt Victoria in the Blue Mountains. There was some damage which is still being repaired but this method has saved the workers from a much greater repair job.


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A valve a day keeps the transistor away...

 
 Return to top of page · Post #: 20 · Written at 9:20:00 PM on 29 January 2020.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5258

The dead weight is by far not a new idea, they actually used it on Gunter's survey chains from circa 16th century onwards & I bet it goes back further than that. Seeing Egypt had permanent survey marks & surveyors (Rope stretchers). Its just adopting something which works.

As noted the new antenna has had a limb bounce off it & several Bird strikes with no casualties: It can distort several feet. The other thing it maintains a constant tension and therefore the sag also remains relatively constant as it heats & cools. Its only got around 12lb on it: Two sash weights. It really doesn't matter which end it goes on. Posts are not stayed & depend on concrete as a dumbbell.


 
 Return to top of page · Post #: 21 · Written at 7:33:16 PM on 1 February 2020.
Flukeoneseventyfive's Gravatar
 Location: Laidley, QLD
 Member since 16 September 2015
 Member #: 1799
 Postcount: 114

G'Day Folks.

I use electric fence wire rope, but the tape is even better. The rope has for conductors, light to put up, very strong.

I have been making End Fed half wave antennas, and I have to say on the amateur bands, I made this one for 80 metres (3.5 MHz) but it also works on the 40 metre Band (7 MHz) and all the bands up to 10 metres (28 MHz).

They are a high impedance antenna and require a matching transformer to match them to 50 oh coax, but that is very easy to make and cheap, parts from Jaycar.

For 2CH it would be around 128 metres, It doesn't have to be in a straight line, you could run it around the fence line, don't worry about the height, it is still going to work. or if you have a high tree in the middle of the yard the center of the antenna can be up in the tree, which would make in an inverted V antenna.

The problem with a lot of AM radio stations in this country, is they either have a requirement to reduce their power level or change their antenna pattern during the evening, normally an hour before sun set and up to an hour after sun rise.

We have 4KQ which plays classic hits, trouble is, at night, the antenna pattern changes and signals to the south west, drop dramatically, hard to hear out here in the Lockyer Valley, during summer, due to the static crashes being higher than the signal.

The current 80 meter end fed half wave, it's roughly 42 metres long, works a treat on 4KQ, I checked the antenna on the antenna analyser and found that there is a resonance around 600kHz, can't figure that, but it's useful.

I am going to build an antenna for 160 Metres (1.8 MHz) for amateur radio use and run another for AM broadcast band run along standoffs off the fence posts.

You will need two matching units for the AM Broadcast band, one to match the antenna to the coax and one to match the radios to the coax, the antenna, due to the matching is a quiet antenna compared to a dipole or a long wire.

The other way is to build or buy an AM modulator, I built a two valve based one, runs off a plug pack and works well.

I use a sony media play the digital version of the walkman , and store all the music on it, along with a few vintage ads and it will play 12 + hours of music.

I have another transmitter project, valve based to build, with around 6 + watts output, I could be tempted to test, it is for 160 metres (1.8 MHz), but could work very well as the local radio station for the mountain here...

Cheers, Folks.
Peter VK4KHP


 
 Return to top of page · Post #: 22 · Written at 9:34:16 PM on 1 February 2020.
Vintage Pete's avatar
 Location: Albury, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 2048

Ive been giving antennas lots of thought and I'm thinking in the long term it may be better to bite the bullet and wire a computer in instead.
That way I can listen to music from anywhere,because its possible I may make a antenna and still only get crap stations.
But I'm still giving it lots of thought.
Pete


 
 Return to top of page · Post #: 23 · Written at 10:40:04 PM on 1 February 2020.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5258

The 70m antenna here was once a "V" one NE the other SE.


 
 Return to top of page · Post #: 24 · Written at 10:41:36 PM on 1 February 2020.
Ian Robertson's Gravatar
 Location: Belrose, NSW
 Member since 31 December 2015
 Member #: 1844
 Postcount: 2373

Pete, if you have a roll of any kind of wire, just run it out along the top of your (wooden paling) side fence, Hook one end up to a radio and see what you get. If it sounds promising, you can do a better job of it.


 
 Return to top of page · Post #: 25 · Written at 2:43:29 AM on 4 February 2020.
NewVista's avatar
 Location: Silver City WI, US
 Member since 10 May 2013
 Member #: 1340
 Postcount: 977

If I was trying to Dx a particular AM station, I would start with a wire its ¼WL (as previously suggested) oriented EW, then use a high performance radio like one made by C-Crane. I have a c-crane model 2, it uses frequency synthesis as well as their patented "dual coil" ferrite rod as well as external Aerial+Earth terminals. Looking at the dual AM windings at each end of ferrite, I note it also has four turns of white insulated wire in the middle of the ferrite stick running to Ext Aerial&Earth (which also connects to shielded RF front-end with another fly-wire.) The specs are at ccrane.com; they state its sensitivity is as high as "35 dBµV/m" (must be good?)


 
 Return to top of page · Post #: 26 · Written at 9:11:37 PM on 4 February 2020.
Vintage Pete's avatar
 Location: Albury, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 2048

As a bit of a test, I ran a long wire too a 16 feet high colour bond frame, I was able to pick up 2CA in Canberra, but lots of noise and faint .
Also 3NE in wangatta and 2AY.
Lots of stations but huge amounts of noise and most are faint. This was done at night.
Maybe worth a shot at building a good antenna.
Pete


 
 Return to top of page · Post #: 27 · Written at 10:07:11 PM on 4 February 2020.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2017

A good test is to compare against reception with your car radio. 3NE for example has always been strongly received in Sydney at night, sometimes even in the afternoon. You should be able to get 2AY night and day, since it is local to you.

2CA is problematic for me, being very weak in the day, and swamped by other stations at night. In the old days it was much better.

It seems you might need a noise-cancelling antenna.


 
 Return to top of page · Post #: 28 · Written at 10:24:40 PM on 4 February 2020.
Vintage Pete's avatar
 Location: Albury, NSW
 Member since 1 May 2016
 Member #: 1919
 Postcount: 2048

Robbert, I think by memory your at Hill top?
Thats a far way from Canberra .
You mean a antenna with a filter?
Ive never used one .
See how we go, pete


 
 Return to top of page · Post #: 29 · Written at 12:15:43 AM on 5 February 2020.
Robbbert's avatar
 Location: Hill Top, NSW
 Member since 18 September 2015
 Member #: 1801
 Postcount: 2017

I move around between Hilltop and Sydney, however the things relevant to this forum are all done at Hilltop.

I'm sure you could google more info about noise-cancelling antennas, but the usual one is a loop antenna. I suspect you could also pass the signals through a balanced RF transformer (not sure of the correct name of it) to cancel common-mode interference. Now that you have the leisure time, you could investigate different antenna designs, seeing as you have a goal of being able to listen to 2CH all day.

In the 70s, reception of 2CA in the daytime in Sydney was not a problem, and at night it was much better. In the 90s, they were quite clear in stereo, on the stereo AM receiver I used then. But I suspect that sometime since, they've had to do some kind of antenna adjustment, resulting in the very poor reception we get now - basically non-existent. The ABC on 666 is still quite audible though.


 
 Return to top of page · Post #: 30 · Written at 9:42:13 AM on 5 February 2020.
Marcc's avatar
 Location: Wangaratta, VIC
 Member since 21 February 2009
 Member #: 438
 Postcount: 5258

The nominal length for most Australian Radios was 25 feet. The "Farm" type radio with a leading TRF stage before the mixer was really the rural radio.

Cities are bigger now and most of the crap has increased & Parliament could be accused of broadcasting it.

The Yaesu 7700 has an antenna tuner and that is quite effective. So building such a thing may not be a waste.

That Electric fence tape is normally SS wire so soldering is liable to be an exercise in futility depending on the grade. E.g. Pots for cooking 316 Utes exhaust likely 414.


 
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