Indoor Shortwave Antenna
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Thread moved to Receive Antennas (Below 30MHz) forum.
ridgescan
Member
I copied these ideas
Attic Antennas
To begin with building and installing an attic antenna that helps your reception, you need to take stock of your attic's measurements, particularly the length of the attic at it's longest distance that you have easy access and your radio's location.
One of the more common house sizes is about 50 to 60 feet long and about 25 to 30 feet wide at the ground level. Your house or home may be entirely different. The accessible attic space usually is much less than this. You will have to really compromise with an attic antenna as far as the band coverage is concerned for a short wave antenna to perform adequately. Use the dimensions of your attic and compare them with the lengths of the long wire and dipole type antennas in this article above and choose the one that you can "fit" into the attic. You may not be able to use lengths for all the bands, but again, no matter what length your end result is, it will certainly outperform that little pip squeak of a poor excuse for an antenna that came with the radio! Just utilize the space that you have and don't worry about the length. Just use as much wire as you can and forget about that "perfect antenna". It still does not exist up to this point in this article! Hams are still working worldwide on it!
The best place to mount or attach the antenna is against the peak or highest part of the roof thereby keeping it away from ductwork, AC and heater systems, telephone and all the other metallic environment that exists in most attics. Once you have the location selected, then build the antenna while keeping in mind that the coax or wire will have to get to the radio. If you're working up on the roof, get a helper to assist, an adult, not children! Be careful on those ladders!
You can push most small coaxial cable under the space where the carpet and wall come together and wire should be no problem, then to the nearest closet, up the wall and into the attic. You can work from the attic down or radio up....your choice. Lots of variables here too so you will have to choose your own route and method of installation. If you have to drill into a wall to feed the wire, use caution and don't drill into electrical wires! It may be the last time you do!
IN ROOM ANTENNAS!
In those cases where you can't put an antenna outside or up in the attic, then you can install it in the same room with the radio! They won't be as effective as those up in the attic or outside but will still get more signal to your radio which is what you want.
Simply use your own method to attach a random length wire, up next to the ceiling against the walls...around all sides of the room if possible. One other choice is to push a random wire between the carpet and the baseboard around the walls of the room. You will be surprised at the difference compared to that telescoping antenna that came with your radio. Just attach the antenna to the telescoping rod...don't forget to remove the insulation on the wire at the attachment point!
from this entry in the Radio Reference antenna wiki
Build a Multiband Shortwave Antenna - Simple Shortwave Antennas for Shortwave Radios!
I will also add my own idea-a metal tape measure. They make pretty decent SW antennas.
this video shows how just 14' of tape measure improves signal on my old Patrolman-9.
http://www.youtube.com/watch?v=DbKVgGJeFvk
Attic Antennas
To begin with building and installing an attic antenna that helps your reception, you need to take stock of your attic's measurements, particularly the length of the attic at it's longest distance that you have easy access and your radio's location.
One of the more common house sizes is about 50 to 60 feet long and about 25 to 30 feet wide at the ground level. Your house or home may be entirely different. The accessible attic space usually is much less than this. You will have to really compromise with an attic antenna as far as the band coverage is concerned for a short wave antenna to perform adequately. Use the dimensions of your attic and compare them with the lengths of the long wire and dipole type antennas in this article above and choose the one that you can "fit" into the attic. You may not be able to use lengths for all the bands, but again, no matter what length your end result is, it will certainly outperform that little pip squeak of a poor excuse for an antenna that came with the radio! Just utilize the space that you have and don't worry about the length. Just use as much wire as you can and forget about that "perfect antenna". It still does not exist up to this point in this article! Hams are still working worldwide on it!
The best place to mount or attach the antenna is against the peak or highest part of the roof thereby keeping it away from ductwork, AC and heater systems, telephone and all the other metallic environment that exists in most attics. Once you have the location selected, then build the antenna while keeping in mind that the coax or wire will have to get to the radio. If you're working up on the roof, get a helper to assist, an adult, not children! Be careful on those ladders!
You can push most small coaxial cable under the space where the carpet and wall come together and wire should be no problem, then to the nearest closet, up the wall and into the attic. You can work from the attic down or radio up....your choice. Lots of variables here too so you will have to choose your own route and method of installation. If you have to drill into a wall to feed the wire, use caution and don't drill into electrical wires! It may be the last time you do!
IN ROOM ANTENNAS!
In those cases where you can't put an antenna outside or up in the attic, then you can install it in the same room with the radio! They won't be as effective as those up in the attic or outside but will still get more signal to your radio which is what you want.
Simply use your own method to attach a random length wire, up next to the ceiling against the walls...around all sides of the room if possible. One other choice is to push a random wire between the carpet and the baseboard around the walls of the room. You will be surprised at the difference compared to that telescoping antenna that came with your radio. Just attach the antenna to the telescoping rod...don't forget to remove the insulation on the wire at the attachment point!
from this entry in the Radio Reference antenna wiki
Build a Multiband Shortwave Antenna - Simple Shortwave Antennas for Shortwave Radios!
I will also add my own idea-a metal tape measure. They make pretty decent SW antennas.
this video shows how just 14' of tape measure improves signal on my old Patrolman-9.
http://www.youtube.com/watch?v=DbKVgGJeFvk
Last edited:
oldradioguy2010
Member
inside SWL antenna
JoJo I had the same (kinda) problem,
so had a small piece of hookup wire with alagator clips and cliped one side to the window metal and the other to my DX390 (rat shack)
works like a champ
give it a shot, you may be suprized
DW
aka
oldradioguy2010
JoJo I had the same (kinda) problem,
so had a small piece of hookup wire with alagator clips and cliped one side to the window metal and the other to my DX390 (rat shack)
works like a champ
give it a shot, you may be suprized
DW
aka
oldradioguy2010
I do o.k. with a 25 ft indoor random wire. It's just speaker wire, stripped in halves. I soldered a mini plug to the end of it, and it plugs into the antenna jack on my DX-390.
The antenna is actually folded on itself, so it may electrically be a bit longer than 25 ft., but that's how long the 'legs' are.
It doesn't work quite as well as the 100 ft. outdoor antenna I had that blew down, but I still hear most of the world. Still hear Asia and Africa, and the Middle East, and sometimes South Asia. I hear KBC from Europe when it comes in, and hear hams from places like Finland and Spain, so it still brings in enough of the world.
An added 'benefit' (if you can call it that) to having an indoor antenna is you don't have to worry quite so much about static electricity from dry winter wind building up on your antenna and zapping your radio's RF transistor. I'm not sure if the Grundig has protection diodes, but a lot of radios don't.
Even with protection diodes added to my radio I am still wary of that... so I've just stuck with my indoor antenna for the last couple years.
The antenna is actually folded on itself, so it may electrically be a bit longer than 25 ft., but that's how long the 'legs' are.
It doesn't work quite as well as the 100 ft. outdoor antenna I had that blew down, but I still hear most of the world. Still hear Asia and Africa, and the Middle East, and sometimes South Asia. I hear KBC from Europe when it comes in, and hear hams from places like Finland and Spain, so it still brings in enough of the world.
An added 'benefit' (if you can call it that) to having an indoor antenna is you don't have to worry quite so much about static electricity from dry winter wind building up on your antenna and zapping your radio's RF transistor. I'm not sure if the Grundig has protection diodes, but a lot of radios don't.
Even with protection diodes added to my radio I am still wary of that... so I've just stuck with my indoor antenna for the last couple years.
ka3jjz
Wiki Admin Emeritus
There's going to be a discussion on this very topic at the 2014 Winterfest in Pennsylvania. Unfortunately due to unemployment (mine), I won't be able to go this year...
In any case, a couple of thoughts...
a. Avoid clipping any wire to the whip of a portable. Static electricity is your worst enemy! One zap and the amplifier that's probably near the base of that whip is gone. Use the antenna jack instead, and put some static protection in line with the antenna. There are many ways to go about this - some folks use 2 diodes, others a small light bulb- but use something. Static electricity can do serious damage this way, too
b. Hands down when you are limited to indoor antennas (I've been for many years), loops of one kind or another are your friend. I *think* Wellbrook used to sell (does it still?) an amplifier you could use with a hunk of wire stretched out as a loop. Since I had an attic in one place I used to live, I constructed the Carpet Loop, detailed here
The Carpet Loop -- antenna special on hard-core-dx.com
It takes a bit of doing, but it's a very nice first project if you've never done something like this. I strung a 25 foot loop around the perimeter of my attic (OK you purists are going to say it acts more like a dipole - you're right, but it worked...) and brought the 2 ends down to the Carpet Loop switchbox. Worked like gangbusters on my RX320 - far and away better than a random wire around the perimeter of the room, or a helical I had constructed. (For those that are curious...)
The McGyver(tm) special - The RadioReference Wiki
I heard several Latins and Africans on the Carpet Loop that simply weren't there with any of the other antennas I built.
Mike
In any case, a couple of thoughts...
a. Avoid clipping any wire to the whip of a portable. Static electricity is your worst enemy! One zap and the amplifier that's probably near the base of that whip is gone. Use the antenna jack instead, and put some static protection in line with the antenna. There are many ways to go about this - some folks use 2 diodes, others a small light bulb- but use something. Static electricity can do serious damage this way, too
b. Hands down when you are limited to indoor antennas (I've been for many years), loops of one kind or another are your friend. I *think* Wellbrook used to sell (does it still?) an amplifier you could use with a hunk of wire stretched out as a loop. Since I had an attic in one place I used to live, I constructed the Carpet Loop, detailed here
The Carpet Loop -- antenna special on hard-core-dx.com
It takes a bit of doing, but it's a very nice first project if you've never done something like this. I strung a 25 foot loop around the perimeter of my attic (OK you purists are going to say it acts more like a dipole - you're right, but it worked...) and brought the 2 ends down to the Carpet Loop switchbox. Worked like gangbusters on my RX320 - far and away better than a random wire around the perimeter of the room, or a helical I had constructed. (For those that are curious...)
The McGyver(tm) special - The RadioReference Wiki
I heard several Latins and Africans on the Carpet Loop that simply weren't there with any of the other antennas I built.
Mike
ridgescan
Member
Have fun and don't be afraid to experiment- there are variables unique to each listening station far as noise & stuff so find out what works best.
Fast1eddie
Member
Ridge, how's the SX-88 doing these days???
If you don't mind paying more money for your antenna than the radio, then this would be ideal and probably your top-of-the-line solution.
LA5030-2 Indoor North Amer. ver. with PSU
ridgescan
Member
Doing great Eddie thanks for asking
sorry the OT jojo11221.oldradioguy2010
Member
Hey jojo, how are the different antennas working?
just wondering what one worked best.
old radio guy
just wondering what one worked best.
old radio guy
oldradioguy2010
Member
when my wife and i lived in the condo, and no external ants allowed, i used the short hook up lead to the window frame.
and it worked great. i still had an outside ant. and they never knew it. BUT our roof neighbor was the condo prez. He was a jerk anyway and i got away with it for about 3 years.
enjoy!
DW aka old radio guy
and it worked great. i still had an outside ant. and they never knew it. BUT our roof neighbor was the condo prez. He was a jerk anyway and i got away with it for about 3 years.
enjoy!
DW aka old radio guy
jojo11221,
I think the best indoor antenna you can use for SW is the "tried and true" resonant loop antenna. I have two loops for SW, one for use above roughly 15mhz, the other covers from the top of the BCB to about 15mhz.
I purchased two childrens "hula hoops", the lower freq loop is 26" in diameter. The higher freq loop is 20" in diameter. Both loops are tuned to resonance by a variable air capacitor.
I've been in this hobby for decades. I tried all sorts of indoor antennas over the years and the resonant loops by far deliver the best signals with the lowest noise. They can be rotated to null out noise and still give the radio a good signal.
Each loop cost me less than ten dollars to make... you can't beat that for performance vs. cost.
I'd bet you'd find a small resonant loop will outperform your 50 ft. indoor wire loop in the signal to noise ratio "department".
I'll give you details if you're interested.
I think the best indoor antenna you can use for SW is the "tried and true" resonant loop antenna. I have two loops for SW, one for use above roughly 15mhz, the other covers from the top of the BCB to about 15mhz.
I purchased two childrens "hula hoops", the lower freq loop is 26" in diameter. The higher freq loop is 20" in diameter. Both loops are tuned to resonance by a variable air capacitor.
I've been in this hobby for decades. I tried all sorts of indoor antennas over the years and the resonant loops by far deliver the best signals with the lowest noise. They can be rotated to null out noise and still give the radio a good signal.
Each loop cost me less than ten dollars to make... you can't beat that for performance vs. cost.
I'd bet you'd find a small resonant loop will outperform your 50 ft. indoor wire loop in the signal to noise ratio "department".
I'll give you details if you're interested.
Attachments
TXBlue2
Member
lofreq, I'm new to the forum but not to SWL. I have a Panasonic DR28 and a Sony 7600GR. I just purchased a Grundig (Eton) 750. I'm interested in this loop antenna you made. Would you mind sending me some good instructions on how to construct this one and also what parts i need to buy? You said that it didn't cost much to make and worked great.
Thanks in advance.
Richard
Thanks in advance.
Richard
Orbit_Uranus
Member
Lowfreq
Post up how to make this hula hoop antenna this looks great
Post up how to make this hula hoop antenna this looks great
ka3jjz
Wiki Admin Emeritus
Au contraire - this is precisely the place where you can 'tie up the thread' with the details of your hula hoop antenna. Post away - the more details, the better
Mike
Even better, add it to the wiki.
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