Shortwave wire length.

[jjhendo]

I'm making a simple wire antenna, 14 awg (which I'm now thinking might be a little heavy to throw up in a tree) and a gator clip. Looking around online, there doesn't seem to be a general concensus on length? I've seen anything from 30-100'. This would just be for a portable radio.

 

[Blackswan73]

If you want an all band HF antenna, 100ft more or less is the recommended length. However you would be amazed how much you can receive with a 66ft length. 66ft is resonant for 40 meters, but also works well on the 20 meter band. Add a tuner and you have a decent antenna for most of the HF range. That being said, I once wound about a 100ft of magnet wire on a foot square cardboard box and was amazed at how well it worked. But to be fair, that was back when the HF bands were filled with 500kw stations from all over the world. I currently have a 66ft EFHW and a KLW-480 loop antenna.

B.S.

 

[mmckenna]

I'm making a simple wire antenna, 14 awg (which I'm now thinking might be a little heavy to throw up in a tree) and a gator clip. Looking around online, there doesn't seem to be a general concensus on length? I've seen anything from 30-100'. This would just be for a portable radio.

What you are talking about is a "random wire" antenna.

Since the shortwave bands cover a huge amount of spectrum, there is no one 'right' wire length that will work everywhere. You either need to use a tuner, or something like an end-fed wire if you want something that is 'tuned' in a loose interpretation of the term.

For a random wire, just pick a long piece and give it a try. Really long wires can be problematic since they can be closer to resonance on the AM broadcast band, and if you have nearby AM transmitters, it'll overload the radio.
Shorter antennas may not work as well on the lower bands.

My first shortwave antenna was probably 120 or so feet of 22 gauge wire stapled along the fence. It overloaded the radio due to AM broadcast, but I heard plenty of shortwave stations.

 

[bharvey2]

For a temporary setup, you can get by with a smaller gauge wire. For longevity, #14 is a good size and is the minimum listed in NEC 810.52 (if that interests you). As has been noted above, there is no real one size fits all for a wire antenna. The best course of action is to determine your bands of interest and what bands your radio is capable of operating. It's often tempting to want to "do it all" but reality tends to temper that after a while. Receiving antennas are far more forgiving when it comes to length and what will work. A random wire length will work. Usually longer is better but YMMV. Experiment and see what works for you. Also, you might consider a loop antenna. I use one for my HF rig for receiving as it is far less noisy.

 

[tuihill]

Antenna Supermarket - Eavesdropper SWL Sloper. I have one of these. Works very well.
https://www.universal-radio.com/catalog/sw_ant/0013.html Discontinued.
You may find one on eBay.
Jack remembers the Eavesdropper Antenna

 

[jjhendo]

If you want an all band HF antenna, 100ft more or less is the recommended length. However you would be amazed how much you can receive with a 66ft length. 66ft is resonant for 40 meters, but also works well on the 20 meter band. Add a tuner and you have a decent antenna for most of the HF range. That being said, I once wound about a 100ft of magnet wire on a foot square cardboard box and was amazed at how well it worked. But to be fair, that was back when the HF bands were filled with 500kw stations from all over the world. I currently have a 66ft EFHW and a KLW-480 loop antenna.

B.S.

This would

If you want an all band HF antenna, 100ft more or less is the recommended length. However you would be amazed how much you can receive with a 66ft length. 66ft is resonant for 40 meters, but also works well on the 20 meter band. Add a tuner and you have a decent antenna for most of the HF range. That being said, I once wound about a 100ft of magnet wire on a foot square cardboard box and was amazed at how well it worked. But to be fair, that was back when the HF bands were filled with 500kw stations from all over the world. I currently have a 66ft EFHW and a KLW-480 loop antenna.

B.S.

Would you use a tuner with a wire just for listening to broadcast shortwave?

 

[jjhendo]

What you are talking about is a "random wire" antenna.

Since the shortwave bands cover a huge amount of spectrum, there is no one 'right' wire length that will work everywhere. You either need to use a tuner, or something like an end-fed wire if you want something that is 'tuned' in a loose interpretation of the term.

For a random wire, just pick a long piece and give it a try. Really long wires can be problematic since they can be closer to resonance on the AM broadcast band, and if you have nearby AM transmitters, it'll overload the radio.
Shorter antennas may not work as well on the lower bands.

My first shortwave antenna was probably 120 or so feet of 22 gauge wire stapled along the fence. It overloaded the radio due to AM broadcast, but I heard plenty of shortwave stations.

I think so? I'm still not totally clear on what a random wire is. I heard about the overloading and was curious why. That makes sense. I might try something around 70'

 

[jjhendo]

For a temporary setup, you can get by with a smaller gauge wire. For longevity, #14 is a good size and is the minimum listed in NEC 810.52 (if that interests you). As has been noted above, there is no real one size fits all for a wire antenna. The best course of action is to determine your bands of interest and what bands your radio is capable of operating. It's often tempting to want to "do it all" but reality tends to temper that after a while. Receiving antennas are far more forgiving when it comes to length and what will work. A random wire length will work. Usually longer is better but YMMV. Experiment and see what works for you. Also, you might consider a loop antenna. I use one for my HF rig for receiving as it is far less noisy.

This is just for broadcast shortwave listening. I was thinking maybe different lengths for day and night to be a little closer to resonant? I have an MLA 30+ but just wanted to try to make something for portable.

 

[mmckenna]

Would you use a tuner with a wire just for listening to broadcast shortwave?

A tuner, if your radio has a coaxial external antenna input, would be something to try. The tuner needs to be one that will work with a random length/long wire.

I think so? I'm still not totally clear on what a random wire is. I heard about the overloading and was curious why. That makes sense. I might try something around 70'

Random wire is just that. It's a random, non resonate, length of wire. It works well for many short wave listeners.

The overloading is what got me when I first started. The old radio was kind of limited in what it could handle, and the strong signal from nearby AM broadcast stations just overloaded the entire front end of the radio, resulting in that AM station pretty much coming through everywhere.

The end fed antennas mentioned above are another good option. You can make them if you want to roll your own transformer. They can be a good 'all around' antenna for this sort of application, and may work better than a random wire, but your radio will need to have a coax external antenna input.

 

[pb_lonny]

A lot of it is trail and error. Start with 66 foot and see if that works well enough, if you go "too long", you can end up with overload.

 

[AB4BF]

I'm making a simple wire antenna, 14 awg (which I'm now thinking might be a little heavy to throw up in a tree) and a gator clip. Looking around online, there doesn't seem to be a general concensus on length? I've seen anything from 30-100'. This would just be for a portable radio.

I had two of these, 1 on a Grundig 800 and 1 on an AM/FM stereo unit that's in my farm shop. I sold the Grundig and antenna several years ago to a fellow ham that wanted it way more than I did, lol. They work as advertised and then some.
This is the one at Solid SIgnal:

Pixel Technologies AM/FM External Outdoor High Definition Radio Antenna (AFHD-4)

Pixel Technologies AFHD-4 Outdoor AM/FM/HD Radio AntennaBest ForHomes, offices, and rural locations that need improved AM, FM, and HD Radio reception from a single outdoor or attic-mounted antenna.Why Choose the AFHD-4?The AFHD-4 is a low-profile omnidirectional radio antenna designed to receive...

www.solidsignal.com

This one is at DX Engineering:

DX Engineering DXE-AFHD-4 DX Engineering AFHD-4 AM/FM/HD Antennas | DX Engineering

Free Shipping - DX Engineering AFHD-4 AM/FM/HD Antennas with qualifying orders of $99. Shop AM, FM and Satellite Antennas at DX Engineering.

www.dxengineering.com

What I can't believe is how much they've increased in price since covid. They were at first $89 plus tax and shipping, but, they are very good antennas.

 

[MUTNAV]

A lot depends on what kind of portable receiver you're talking about. Just guessing here but something like a Tecsun Pl-880 might not do well with a long wire, it's already pretty sensitive.

So what kind of portable are we talking about?

Thanks
Joel

 

[bearcatrp]

I picked up a par end fed antenna. Great for those trips you want to just through a line over a tree limb to listen. I swapped there line with a spool of wire I bought at Home Depot and ran a longer wire. It’s what I’m using at home.

 

[jjhendo]

A tuner, if your radio has a coaxial external antenna input, would be something to try. The tuner needs to be one that will work with a random length/long wire.




Random wire is just that. It's a random, non resonate, length of wire. It works well for many short wave listeners.

The overloading is what got me when I first started. The old radio was kind of limited in what it could handle, and the strong signal from nearby AM broadcast stations just overloaded the entire front end of the radio, resulting in that AM station pretty much coming through everywhere.

The end fed antennas mentioned above are another good option. You can make them if you want to roll your own transformer. They can be a good 'all around' antenna for this sort of application, and may work better than a random wire, but your radio will need to have a coax external antenna input.

Is it normal for them to overload anyway? I was turning the dial and heard AM on my old Holiday and even the Tecsun!

 

[jjhendo]

I had two of these, 1 on a Grundig 800 and 1 on an AM/FM stereo unit that's in my farm shop. I sold the Grundig and antenna several years ago to a fellow ham that wanted it way more than I did, lol. They work as advertised and then some.
This is the one at Solid SIgnal:

Pixel Technologies AM/FM External Outdoor High Definition Radio Antenna (AFHD-4)

Pixel Technologies AFHD-4 Outdoor AM/FM/HD Radio AntennaBest ForHomes, offices, and rural locations that need improved AM, FM, and HD Radio reception from a single outdoor or attic-mounted antenna.Why Choose the AFHD-4?The AFHD-4 is a low-profile omnidirectional radio antenna designed to receive...

www.solidsignal.com

This one is at DX Engineering:

DX Engineering DXE-AFHD-4 DX Engineering AFHD-4 AM/FM/HD Antennas | DX Engineering

Free Shipping - DX Engineering AFHD-4 AM/FM/HD Antennas with qualifying orders of $99. Shop AM, FM and Satellite Antennas at DX Engineering.

www.dxengineering.com

What I can't believe is how much they've increased in price since covid. They were at first $89 plus tax and shipping, but, they are very good antennas.

I'll look at em. Have to figure out what to do with this wire first. Hi hi

 

[jjhendo]

A lot depends on what kind of portable receiver you're talking about. Just guessing here but something like a Tecsun Pl-880 might not do well with a long wire, it's already pretty sensitive.

So what kind of portable are we talking about?

Thanks
Joel

Well, I have a Tecsun PL 660, but this is more for my old Holiday (or Air Castle, ot other names that radio goes by) that does't have the external jack.

 

[mmckenna]

Is it normal for them to overload anyway? I was turning the dial and heard AM on my old Holiday and even the Tecsun!

Yes, on some radios. It's a trade off between price, sensitivity and selectivity. Get a fancy, high dollar radio, and it won't suffer from that problem quite as much. But you can always shorten the antenna on yours.

Well, I have a Tecsun PL 660, but this is more for my old Holiday (or Air Castle, ot other names that radio goes by) that does't have the external jack.

Without the external antenna jack, there's not much you can do. Alligator clip to the extend-o antenna is one of the options you have. Capacitive coupled loop is the other.

Just be careful with really long wire antennas clipped to the telescopic antenna. Sometimes they'll generate a lot of static electricity and zap the soft bits inside your radio.

 

[G7RUX]

I think so? I'm still not totally clear on what a random wire is. I heard about the overloading and was curious why. That makes sense. I might try something around 70'

One of the advantages of using a tuner for receive is that it also acts as a simple bandpass filter/preselector, so can help reduce overload problems in many cases.

 

[MUTNAV]

Some ideas.

Ferrite Antennas for the Ultra-Light Radio

This is Canada's original radio website - since 1996!

dxer.ca

https://peditio.net/utility/pdf/Antenna_Couplers.pdf

Static drain for outside long wire antenna

Up until now I've used the old tube radios I collect and restore for DXing. I use a 50' outside wire for my antenna. Static (other than lightning) isn't a problem for tube radios. But I decided I wanted to try one of the new portable radios and ordered a Tecsun PL-880, which should arrive in a...

forums.radioreference.com

I thought the Tecsun PL660 had a FM/SW antenna jack on it (just below the hand strap).

For SW/FM it can use the whip or the connector, for MW I guess it uses the interneral ferrite (where a coupler might be useful).

 

[KB2GOM]

If your radio does not have an external antenna socket. I would suggest a very simple, cheap experiment. Get yourself about 20-feete of insulated conductive wire, attach it to an alligator clip, and clip it to the whip antenna on your radio, and see what kind of improvement you get.

Also, this: Some really inexpensive ways to perhaps improve your shortwave listening

and this: A HUGE difference . . .

This also might be of help: Jock designs a Horizontal Room Loop to cope with reception issues

Whatever you do, do not ever, under any circumstances, string up your antenna where it could fall on a power line or a power line could fall on it.