HF ANTENNA IN APARTMENT?

[NeWcS]

Im looking for a good indoor antenna as I live on the 2nd floor of an apartment. I want to listen to radio communactions. Im not to interested in shortwave radio shows. Is this possible with-out having a long wire antenna outside?

Thank you,

-Jay

 

[K7TKR]

With a long wire-absoutly. I suspect, that you meant without a longwire-and that's a bit more of a problem. One of the things I suggest is looking at "active" antennas. These boost the gain to the receiver and trick the receiver into thinking it's connected to a properly tuned antenna.

There are several other options. The ARRL has books on "stealth" antenna designs and such-you might want to look into these also.

 

[SAR923]

I've got a Radio Shack Amplified Shortwave Antenna. It just sits on my desk with a 25 inch telescoping antenna. You can control the RF gain and peak or null signals as needed. I also have a trapped, longwire antenna and use both on my Grundig YachtBoy 400PE. With very few exceptiosn, the active antenna performs better then the long wire, particularly in high noise locations. I've been very impressed with RS antenna.

 

[ka2mek]

Is this possible with-out having a long wire antenna outside?

Thank you,

-Jay

YES it is possible.
KA2MEK

 

[NeWcS]

I've got a Radio Shack Amplified Shortwave Antenna.

I looked on Radioshack.com and can't seem to find it?

I read somewhere on the web about using the phone lines in your house as an antenna. Im going to give this a shot.

Thanks

-Jay

 

[loumaag]

I read somewhere on the web about using the phone lines in your house as an antenna. Im going to give this a shot.

I would be pretty cautious about this approach. The "ring signal" on a telephone can be anywhere from about 48V to 150V AC. (Depending on loop length.) If you don't think that won't mess up the input circuits to your radio, think again! :shock:

 

[NeWcS]

I tried it wit a cap inline. I didnt really work to well. found out if I unpluged it from the wall it worked better

Anyone have any good ideas about setting up some sort of indoor antenna. Would REALLY like to try and listen to some milair.

Thank you,

-Jay

 

[ka2mek]

ALRIGHT!
Just what is that jumping out at the toddler!


is it a MONKEY or a CAT!
My wife saiz CAT~ I say Monkey!
please settle this ASAP.
Thank You
73
Rob

What is it!

 

[SAR923]

It's an RS 20-280 and it looks like it's discontinued, darn it. You might be able to find some either as old stock in an RS store or on e-bay. I paid $30 for it on sale - regular price was $60. Not only is this good as an amplified antenna but it also acts as an antenna tuner if you run a long wire through it. Too bad RS didn't keep it going since it's a good, cheap active antenna.

 

[NeWcS]

ALRIGHT!
Just what is that jumping out at the toddler!

LoL, Its a cat

 

[ullbergm]

ALRIGHT!
Just what is that jumping out at the toddler!

Hehe, its a cat..
About 1:10 into this clip you have a larger version
http://mismedia.net/media/funny_cats_1.asf

 

[kingpin]

I had a similar problem a few years ago and over came it. I took 5" pvc pipe ( I worked for the phone company and had access to some" and made a 30 meter dipole centered around 10 mhz. I listen to allot of things in that neighborhood so it worked well. took rg8 goax and soldered 60 ft or wire to the center conductor and 60 to the braid. affixed the coax to the middle of the piple and wound in opposite directions, the wire around the pipe in a spring type fasion. I used 20 guage stranded by the way. I taped the ends to the pipe to keep them from unwrapping and hung it parralel to the ceiling. The whole thing was5 ft long. I kept the windings about 2-3" apart to minimize induction and it worked fine. My transceiver had an auto tumer and it tumed it well . (DON'T TX WITH IT IF YOU ARE USING THIS ANTENNA) If you just have a receiver, an antenna tuner can be found for not a whole lot of money and can help tune the antenna for better reception in the freuencies you want to listen to!

 

[ka2mek]

ALRIGHT!
Just what is that jumping out at the toddler!

Hehe, its a cat..
About 1:10 into this clip you have a larger version
http://mismedia.net/media/funny_cats_1.asf

Thank You!

73!
Robert-KA2MEK

 

[gopherit]

Antenna in Apt.

I use a mag mount mobile WSM1900 Antenna siting on top of my Fridge works very well, can get a good signal from 7 towers in the Toronto Area. on 10th. floor. get a fair signal at my Brothers Basement Apt. as well. :wink:

 

[SCPD]

Forget what there called, But have you tried one of those Tunable HF Whip antennas for Mobile use? Covers 180 meters to 15 meters well. just need a power supply for the rotar. like a 6v or a 9v should work.

MT

 

[loumaag]

Forget what there called, But have you tried one of those Tunable HF Whip antennas for Mobile use? Covers 180 meters to 15 meters well. just need a power supply for the rotar. like a 6v or a 9v should work.

Screwdriver antennas. Most are designed for 12v (since that is what most cars have). But that is a pretty expensive route and wouldn't fit in an apartment anyway (too tall). Very few screwdriver antennas cover 180 meters BTW. When tuned for 80 meters, the coil and whip combination go to about 13 feet.

Any vertical antenna is going to be prone to pickup more man made noise, so try and stay horizontal. You could just hang a dipole in the room and run it around the wall/ceiling joint. Judicious choice of color on the wire would help with the static (non-electrical) from any other occupants of the apartment.

 

[K7TKR]

Forget what there called, But have you tried one of those Tunable HF Whip antennas for Mobile use? Covers 180 meters to 15 meters well. just need a power supply for the rotar. like a 6v or a 9v should work.

A screwdriver may a little bit overboard for what he wants to do. Those things, like my own AH-6 for my Icom require a darn good system as well which, he may not have. Then there's the challenge of where to mount it.

However, getting a CB antenna such as a Wilson and a small manual tuner may also work-I've actually done this and had good enough reception to copy HF weather fax.

 

[ka3jjz]

Unfortunately, without some idea of the receiver being used, it's difficult to make a good recommendation (I ran a scanner/swl net in the Baltimore area for almost a decade so I've seen this question before :wink: )

If your receiver can accept a 50/75 ohm coax input, here's an interesting suggestion that Tom Alleman of NASWA fame made many years ago, and I've used it to good effect; make 4 25 foot lengths of wire, connect 2 to the braid, 2 to the center conductor. Feed with a length of RG59U 75 ohm coax or similar (I've tried 50 ohm coax and it didn't work as well) . String the 4 lengths outward in a fan shape - voila, you have a small fan dipole. It's untuned (a small coax tuner might help, again depending on your receiver), and the fact that it's fed with coax will help keep the noise level down somewhat.
You can even tune this somewhat by making the 4 lengths resonant; 2 lengths would be resonant to the lowest band of interest, the other 2 the highest. You would simply use the famous 468/f(mhz) formula, then divide the resulting length in half to find out what the correct lengths would be for each leg. I did this using 4 and 16 mhz as my low and high points, and it worked pretty well. I did use a small MFJ tuner at the time.
Sadly the components for making tuners are getting harder and harder to find; there are numerous schematics in ham books, mags and such, but the parts are another matter. Tuners aren't all that expensive, tho, particularly for listening applications; for us hams, who can run lots of power, that becomes a little more of an issue.

73s Mike

 

[ka3jjz]

I had a similar problem a few years ago and over came it. I took 5" pvc pipe ( I worked for the phone company and had access to some" and made a 30 meter dipole centered around 10 mhz. I listen to allot of things in that neighborhood so it worked well. took rg8 goax and soldered 60 ft or wire to the center conductor and 60 to the braid. affixed the coax to the middle of the piple and wound in opposite directions, the wire around the pipe in a spring type fasion. I used 20 guage stranded by the way. I taped the ends to the pipe to keep them from unwrapping and hung it parralel to the ceiling. The whole thing was5 ft long. I kept the windings about 2-3" apart to minimize induction and it worked fine. My transceiver had an auto tumer and it tumed it well . (DON'T TX WITH IT IF YOU ARE USING THIS ANTENNA) If you just have a receiver, an antenna tuner can be found for not a whole lot of money and can help tune the antenna for better reception in the freuencies you want to listen to!

I've seen a couple of ham antenna books with this design - you CAN transmit with this antenna with a very slight upgrade in the materials; one book used 16 gauge wire and I think another had a different feed method,
Don't be so quick to dismiss homebrew ideas like this - it can, and sometimes will, surprise you.

73s Mike

 

[NeWcS]

Unfortunately, without some idea of the receiver being used, it's difficult to make a good recommendation (I ran a scanner/swl net in the Baltimore area for almost a decade so I've seen this question before :wink: )

If your receiver can accept a 50/75 ohm coax input, here's an interesting suggestion that Tom Alleman of NASWA fame made many years ago, and I've used it to good effect; make 4 25 foot lengths of wire, connect 2 to the braid, 2 to the center conductor. Feed with a length of RG59U 75 ohm coax or similar (I've tried 50 ohm coax and it didn't work as well) . String the 4 lengths outward in a fan shape - voila, you have a small fan dipole. It's untuned (a small coax tuner might help, again depending on your receiver), and the fact that it's fed with coax will help keep the noise level down somewhat.
You can even tune this somewhat by making the 4 lengths resonant; 2 lengths would be resonant to the lowest band of interest, the other 2 the highest. You would simply use the famous 468/f(mhz) formula, then divide the resulting length in half to find out what the correct lengths would be for each leg. I did this using 4 and 16 mhz as my low and high points, and it worked pretty well. I did use a small MFJ tuner at the time.
Sadly the components for making tuners are getting harder and harder to find; there are numerous schematics in ham books, mags and such, but the parts are another matter. Tuners aren't all that expensive, tho, particularly for listening applications; for us hams, who can run lots of power, that becomes a little more of an issue.

73s Mike

WoW, I just put alittle something together and thanks for suggestion. With the antenna I was using before I could bairly hear the station I was using to test. With your suggestion I am now hearing the same guy I couldnt hear beofre @ about 4s. 14244 Some guy In HI.

Thanks again.

BTY, im runnign a DX300 and am in Colo