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PostPosted: June 26th, 2018, 2:10 pm 
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I have a cc crane skywave am/ fm radio. Does anyone have any wilderness techniques that will increase its range?


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PostPosted: June 27th, 2018, 6:22 am 
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Location: Milton
A lot depends on the area you are in.
Local topography can make a huge difference.
For the AM bands you can get a lot of radio skip during the night, nothing local but it is fun to find what stations you are getting.
For the weather bands it also depends on the area.
The last two years is the first time I have been able to get the weather report the entire way through Agawa Canyon.
Still only skip at night.
Jeff

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PostPosted: June 27th, 2018, 8:39 am 
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Location: Guelph, Ontario
As Jeff say location plays a big part. The high ground is better for reception. There is a bunch of things you could buy, a different radio, an extra antenna with some induction connection etc. There is bunch of stuff out on the internet about things people have built to improve cell phone reception in remote locations but when back country camping I figure the intent is to minimize the items we carry.

I had an electronics teacher in high school (yes, back in the 70s) that told us the story of being at a car camping site with his TV because he didn't want to miss an episode of his favourite show (this a story from the 60s which was prior to VCRs being a common household electronic item and on-demand hadn't been imagined yet) but that he forgot the rabbit ears antenna for the TV. So not to miss his show he did a calculation of the ideal length required for a dipole antenna based on the frequency he was trying to capture. With that half wave length distance calculated he cut a coat hanger to that ideal length, wired it to the 300 ohm connection on the TV and was able to watch his show.

The antenna on your cc crane Skywave radio is half of a dipole antenna. The directions in the online manual for it say to extend it fully vertically but I believe, and I could be wrong, that if you make a calculation for the frequency that you are trying to capture to determine the ideal length of the antenna and only extend it to that length (a half or quarter length of frequency wave length) that you will be able to improve reception. The other component to signal reception with a dipole antenna (rabbit ears) is the direction they are turned which changes the signal reception.

basics of a dipole antenna

http://www.radio-electronics.com/info/a ... dipole.php

the length calculation

http://www.radio-electronics.com/info/a ... ormula.php

theory on antenna orientation

http://www.radio-electronics.com/info/a ... tterns.php

I suspect a bit more research in this area could lead you to more concrete advice than mine.


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PostPosted: June 27th, 2018, 9:15 am 
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Do you have a local Ham radio club?
Go there and ask for help - maybe you'll get lucky and find a backwoods camper.


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PostPosted: June 27th, 2018, 11:20 am 
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Thanks for the replies.I l will try a few suggestions


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PostPosted: June 29th, 2018, 7:26 am 
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I use a small Grundig (Eton) that has an antenna gain switch that provides pretty good backcountry reception. In fringe areas I wrap a piece of snare wire around the antenna and spread it out until reception improves.


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PostPosted: June 29th, 2018, 10:04 am 
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Location: Ottawa
A couple of observations. The SW bands which are in the HF (high freq) spectrum and operate using the "skip" effect, work best with long antennae, i.e. at least somewhere between 15ft and 25ft. So attaching some wire to the antenna and stringing it up or between trees will help for stations in the SW band.

For stations in the FM band which operate on "line of sight" this will be more challenging. Ideally you need to be as high as possible. Climbing a tree not a good option :) The antenna length for the WX band is around 3ft (those freqs are in the 162.XXX range) so adding wire to make the antenna three or four feet might help.

Another tip is to ground the radio. Many receivers have a lead you can run a wire to the ground. I don't see one on your radio. So placing the radio away from a dry area. For example sitting on grass would get better reception that sitting on pavement or rock.

Hope that helps.
MikeD.


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PostPosted: June 29th, 2018, 11:55 am 
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Thanks for those last two practical tip!


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PostPosted: June 29th, 2018, 2:58 pm 
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Location: Toronto, Ontario Canada
Another option to consider is a small portable SiriusXM receiver, there are some very small units out there.

Apparently there are also apps for smartphones that will work for SiriusXM.

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PostPosted: June 30th, 2018, 6:48 am 
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I tried Sirius briefly when it was offered free on a trial basis... the CBC radio stations that I was used to were not the same as what was available on Sirius. So the CBC regional weather reports which were helpful weren't available either. At least they weren't several years ago.

There are vids and web pages out there describing how to make antennas to pull in distant stations. Good info here & have been thinking about the Crane Skywave.

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PostPosted: July 12th, 2018, 8:22 am 
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As Dave_k said, focusing on the antenna is key.

The best results will be from a resonant antenna where the wire length is cut according to the frequency you want to listen too. Both the radio, and the antenna, need to be tuned, so to speak, not just the radio's dials.

With the attached telescoping antenna, there will not be as good as reception as you could get with a larger wire. On your radio you can simply unscrew the telescoping antenna and get a connector to attach a longer wire.

The transmitted signals bouncing around also get polarized. So, at times, a vertical antenna may work better; others times, a dipole. Matching the receiving antenna's polarization to the incoming signals' polarization will make things better, assuming you have two different antenna with different polarization to make a test, so to speak, to see which one will work better at any given time. This is known as the Polarization Loss Factor or polarization mismatch loss. In the video I mentioned in the other thread, where I was talking to my friend in his camp in BC from my camp in Ontario, I had put up two antennas for this very reason, one vertically polarized another horizontally polarized. On this day, the vertically polarized one was better for both reception and transmission. Other times, I can often hear better with one antenna and be heard better on another; hence I made a little switch to instantly change antennas when I am trying to talk to someone. Indeed, older radios from the 60s or so often had two antenna ports, one for RX and one for TX. My camp's radio bag includes 2 verticals and one dipole to account for polarization losses.

If you know what frequencies you want to listen too, you could calculate the ideal length for each frequency. As the frequency lowers, the wire length needed will get longer. To have one antenna for many frequencies, one can add in links, like this:

Image

If you want to listen to 14.000, you need about 5m; so, put one of these at the 5m point; if you later want to listen to, say, 7.14, you need to add in the another length of pre-cut wire simply by clipping the alligator clips together, and so on for any of the frequency bands you want to listen to.

My main or default antenna that I made is a 20/40/80m linked dipole with a small section for 2m. It is designed for transmitting, where keeping the antenna resonant and matched to the radio is even more important than when just receiving.

For, say, 98.7, CBC, a 1/4 wave vertical antenna is 2ft. 4 - 15/32in. or 0.723 M.

For, say, Radio Havana, on 6145 kHz, the 49m band, that's 38ft. 0 - 31/32in. or 11.607 M for a a 1/4 wave vertical.
Dipoles will have twice as much wire, one for each side.

My dipole for 80m is about 63' per side, so, about 126 feet of wire in total. That will pick out even super weak signals on that band and, when I transmit, using .5 watt of power I can talk to people all over Ontario from my camp. You can see that antenna here: https://youtu.be/QqXlNOXW0Yw?t=7m15s

So, asking that little antenna on that radio to pick up everything from local CBC to shortwave stations is a lot to ask.

Terrain, topology and frequency play a role too; some frequencies are absorbed by trees, the sky, others refracted out into space; and this changes during the day/night and winter/summer cycle too. As other said above, grounding the radio can draw off static the antenna is picking up from the air around it; that can improve things a bit too, but I have found the effect marginal.

There are special designs for receiving antennas; the beverage antenna is a super famous example. https://en.wikipedia.org/wiki/Beverage_antenna.

You could, for some of the higher frequencies, build a tiny 'yagi antenna'; this will pull signals out. In grey county Ontario, with a 'normal antenna' I can barely pick up the local government weather station. But, if I put my home-made yagi in the radio I can pick up weather stations in Michigan. But, this antenna is directional so you need to point it in the right direction. But there are way to cumbersome for those frequencies requiring a large amount of wire.

Lots of gimmicks and fancy claims are made about coils and other such things, especially with broadband antennas where the wire length is kept constant but is instead coiled or wrapped around or through magnets before going into the radio; but these have more to do with impedance matching than improving reception or transmission. I don't use any of those types of tricks- signal tends to get turned into heat - as you can see here: http://g8jnj.webs.com/cometcha250b.htm

I had a good 30 minute chat with a scientist at the Neutrino Observatory in Antarctica (https://icecube.wisc.edu/) last winter when in my camp out in the woods. Super cool science going on there! That signal was sent/received using a resonant dipole, 32 feet per side - so, about 64 feet of wire hanging in from a tree, about 20 feet up in the middle and about 8 feet off the ground at each end with about 40 watts of power, running off a small battery.

It is interesting to note that your radio's company sells an external SW antenna on a reel: https://www.ccrane.com/item/ant_sw_cc_r ... el_antenna

But, that is only 23 feet long ;). So, not very long at all given my wires' size; but, it is telling about what is necessary to improve reception.

If, as you said in the other thread, you are interested in ham radio, the material covered in the books will address this sort of question. And not only will you be able to listen to Radio Havana, you could easily talk to some Cubans - or even one day me too - while sitting about your camp, cigar in hand.


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PostPosted: July 12th, 2018, 12:23 pm 
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Thank you Modustollens for sharing your expertise.I will go to the longer wire for the antenna for my next trip.If I purchase the radio you recommended can I immediately begin listening with no restrictions? I just need the licence to transmit? Is this correct?


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PostPosted: July 12th, 2018, 1:53 pm 
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Location: Guelph, Ontario
Thanks, I appreciate the clarification. I didn't know about the horizontal & vertical polarization.
:D


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PostPosted: July 12th, 2018, 11:01 pm 
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D.B Cooper wrote:
If I purchase the radio you recommended can I immediately begin listening with no restrictions? I just need the licence to transmit? Is this correct?


Yes, listening is free of charge, so to speak.

Unfortunately, the radios are not, nor are they cheap.

The one I have, the 817, has been updated to the 818; nothing had changed save for a few internal parts. The design is pretty much optimal and it is certainly one of the most popular for a bush radio. It is tough and rugged and very hard to break. Mine's been everywhere, winter, summer, canoe, kayak, airplanes, etc..

It only transmits at 5 watts, but there are amplifiers for it that will take it up to 50; I have such an amp; it is a bit smaller than the radio. Having more power is useful for transmitting; but, there are practical limits to how powerful a radio I want given that I want to be able to carry the radio and the power supply; batteries are heavy. And, to be honest, the antenna is key. Hence why I carry such big antennas.

Radio World in Toronto sells them:

https://www.radioworld.ca/yaesu-ft-818

Many people use this one too:

https://www.radioworld.ca/ya-ft891

It can transmit at 100 watts. But this one is heavier, larger and needs more power.

All of these can be bought used; but, they hold their value pretty well.

The newest, fanciest, and most modern tiny radio is the KX3:

http://www.elecraft.com/KX3/kx3.htm

Very nice - smaller, lighter, more transmit power, and with more modern options (for this is a software defined radio) such as notch filters - these are useful for isolating weak signals. But, the price tag is not for the underpaid. It is a pound or so lighter than the 817; I may, if I am flush with cash one day get one.

If you are looking for a simpler or cheaper radio or one just for receiving, one key spec to consider is the selectivity and sensitivity of the receiver:

https://en.wikipedia.org/wiki/Selectivity_(electronic)
https://en.wikipedia.org/wiki/Sensitivity_(electronics)

"Selectivity is a measure of the performance of a radio receiver to respond only to the radio signal it is tuned to..."

"Receiver sensitivity indicates how faint an input signal can be to be successfully received by the receiver, the lower power level, the better."

You want a radio that is picky with good ears, so to speak.

I tried to find the the specs for these on the cc crane radio you have; but even the manual I downloaded for it did not give those specs. It may be that it is simply not a very good receiver.

I have a grundig e100 and it is a terrible receiver compared to my 817. I can never pick up the North Koreans with it; but, the 817 has no trouble doing that.

One of the books I own about antennas has a chapter on the way an antenna interacts with the landscape; and, it is possible to choose places to put up the antenna such that the ground will help concentrate the signal or reflect and push the energy in one direction rather than omnidirectionally, thus sending more power in one direction, enabling a person to hear or talk to someone further away than would occur on simple ground. See: Freznel Zones, Slopes and Curved Surfaces. Indeed, when I am looking for a camp now I often choose a place with radio-friendly features rather than one that is otherwise a good place for a shelter.

MT


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PostPosted: July 13th, 2018, 5:16 am 
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The 818 will probably be a fall purchase from radio world.For rest of this season I will bring wire and work on some suggestions you gave re attennas for my crane.many thanks


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