Indoor antenna (city living scanning) suggestions?

[gdaykoloa]

I live in a high-rise building in Melbourne (Australia) where external antennas are prohibited by "the rules" - which has meant that my SDS-100 was primarily just being fed by various handheld antennas. That works, but, I actually am looking for something that I can place in the window that maybe increases my UHF/VHF scanning reception.

I found a few inexpensive options on Amazon (Fosa 30MHz -1200MHz Wideband Scanner and another, similar "wire attached to window with suction cup" option) but realise that I can probably do better. These are working (surprisingly) well in the mean time.

Luckily, I've got floor to ceiling windows, and an incredible view out of them, but, I realise that on this side of the glass (+steel, +the rest) that I'll always lose a bit of signal.

I'm not doing any transmitting, just receiving, and mostly UFH/VHF ranges (not a lot of 800MHz active here), but I want something that does have some flexibility and isn't too restricted in its tuning, if possible.

I reckon that there are probably some mobile antennas (like the Larsen NMO150-450-800 Tri-Band) that may work well, but was wondering if there were other suggestions people had who had tried things out in a similar situation.

Thanks!

 

[Firekite]

There are a number of wideband antenna options for receivers. Have you considered a discone, for example? You could hang it from the ceiling somewhere inside, either “right side up” or “upside down”, and maybe even make it look like an interesting conversation piece in the process

There are small “mobile” ones like the the Diamond D220R and larger “base” ones like the Diamond D130J. If you don’t need the low end of reception below VHF, you can forgo the vertical whip and keep it more compact. Otherwise it’s hard to find a good wideband antenna that works well for all receive.

1/4 wave mobile NMO antennas require a ground plane to work at their best, but if you have a reasonably large metal surface to which you can affix an NMO mag mount (or even drill and install a proper NMO mount), there are numerous antenna options, of course. The Larsen NMO150/450/758 is a great compact antenna for scanners, and a number of people have done something like mag mount or drill a top of a file cabinet and get reasonable function out of something’s like that. It depends on how much you expect out of it, and on what frequencies. The lower the frequency, the bigger the ground plane required for optimization.

If your demands aren’t extreme, just a good VHF/UHF HT antenna like the Diamond RH77CA with a BNC adapter installed on your SDS100 does well for listening, at least from airband to 900MHz. If you’re limited to inside your apartment, there’s only so much “external” antennas mounted inside will do for you, and an HT antenna will keep an HT mobile.

 

[gdaykoloa]

Thanks for these great suggestions, Firekite - there were a few other factors I forgot to mention that play into my decision...

First, WifeFactor. A large discone anywhere is just not going to happen. And I'm okay with that; they aren't the best looking things out there.

Second, I don't want anything directly attached to the SDS100, as I have that resting on my desk, mostly acting like an SDS200 in that regard; and take it mobile from time to time (like to sit outside on the balcony, trips, playing with CC mode near interesting things happening in town)...but when at home, I just keep it as minimal base station, and want an antenna I can put up against the window, in the corner, whatever, that isn't too obvious, but I can run a cable to/from somewhat discretely.

The NMO option is interesting. My windows are all aluminium though, nothing magnetic, so, not sure how that would impact the ground plane. Since they are floor to ceiling, there's definitely a large metal surface towards the floor, but, it may not provide the electromagnetic voodoo required.

The D220R looks quite interesting. I could probably find a way to mount that in a non-visible location under the desk at the window...

Thanks for the suggestions!

 

[trentbob]

If I could suggest especially with those large windows. It's something I used to do when I was younger and lived in apartments.

Assuming that you don't listen to much VHF low-band, I would get an inexpensive VHF High, UHF, 7 - 800 megahertz ground plane or similar rooftop antenna with elements that aren't more than 15 in long.

Using good low loss coax mount it on a long broom handle or even better a standing lamp or standing hat rack. Try to get it as high as possible so you don't poke your eyes out with the radials and for the best reception.

This would be a moveable antenna so you could find that sweet spot where I'm sure it'll be close to the window.

You have the advantage of an outdoor antenna that's mounted on a long broom handle, stand-up lamp or stand up hat rack.

I know it sounds strange but you have the advantage of picking out the rooftop antenna that you want, as long as it's not too big and being able to position it around the room near the window for best results. I would think 10 to 20 feet of good quality low loss coax should do the job.

Give it some thought.... Bob.

 

[mmckenna]

Give it some thought.... Bob.

I think that is your best bet. If you don't have a balcony, you can still use it inside. Having where you can pull it out of a closet and put it near the window when you want to listen is a good approach. A broom handle, length of sprinkler pipe, etc. will work. A bucket, flower pot, etc. can be the base. You can fill it with cement, rocks, anything heavy. Mount the antenna on top and you're good to go.

I used to have a flood light like that I used in my garage, a gallon bucket with a 6 foot long piece of 1/2" conduit with the light mounted on top.

One issue you may find is that the glass will have a tint to it. Sometimes that is a metallic film used to reflect light and make the building cooling more efficient. That metal film can block radio waves. Nothing you can do about it, other than be aware.

A base antenna will work.
The Larsen NMO-150-450-800 will work, too. Make sure you add the ground plane kit to get the most out of it, though:
https://www.theantennafarm.com/catalog/laird-technologies-mbcn-7531 (even though the specs say 0-512MHz frequency range, it'll work just fine above that.)

 

[mmckenna]

I'll add that microphone stands and old camera tripods are perfect for this sort of stuff. Old home movie/slide projector screens will work too if you remove the screen part.

 

[jaspence]

I use a metal safe on a wire shelf in my closet with a mag mount for my 2 meter/70 cm radio. Coverage is good and it is out of sight. I have also seen people use a tin cookie sheet, baking pan, or flat piece of metal with success. You even use this on finished wood or plastic with stick on felt pads to prevent scratching the underlying surface.

 

[Firekite]

You have the advantage of an outdoor antenna that's mounted on a long broom handle, stand-up lamp or stand up hat rack.

You know, seriously, depending on your aesthetic and creativity, you can decorate up a small discone. Spray paint it if necessary, decorate it with non-metallic stuff, put wood rings up the cone radials, hang figurines of vaguely exotic origin off the cone radials, you name it. Make it something that complements most themes.

One issue you may find is that the glass will have a tint to it. Sometimes that is a metallic film used to reflect light and make the building cooling more efficient. That metal film can block radio waves. Nothing you can do about it, other than be aware.

That’s a great point I didn’t think of. Does rubber ducky reception drop off significantly when walking inside from the balcony? If not you should be fine.

Make sure you add the ground plane kit to get the most out of it, though:
https://www.theantennafarm.com/catalog/laird-technologies-mbcn-7531

Good call!

 

[trentbob]

You know, seriously, depending on your aesthetic and creativity, you can decorate up a small discone. Spray paint it if necessary, decorate it with non-metallic stuff, put wood rings up the cone radials, hang figurines of vaguely exotic origin off the cone radials, you name it. Make it something that complements most themes.



That’s a great point I didn’t think of. Does rubber ducky reception drop off significantly when walking inside from the balcony? If not you should be fine.


Good call!

Yes I agree you can make a discone look good. It was the o p who rejected the discone secondary to the wife factor LOL.

Now I understand why my post was the only one you didn't like hahaha.

You guys should know that years ago when I used to do this in the 70s when I was in college I would slap that broom handle up on the standing lamp with tape.

I wasn't thinking about how it looked
I can certainly understand the decor factor involved and of course the wife factor.

I just recommended the small ground plane because of the size and that's what I used to use but a small discone can work also.

The bottom line is it really works.

 

[vagrant]

"...an incredible view..." Your residence elevation above average terrain is a boost toward your endeavor. Here is what I do for low profile reception on VHF/UHF when residing in buildings in major cities.

I use the Diamond RH77CA as previously noted. This antenna works very well on those two bands. I attach it to a window using a suction cup BNC mount. I bring a little extra thin coax to fit my needs. You may need to do that as well. Most of the radio traffic I monitor is going through a repeater, so it does not take much to receive it as the signals are strong at the higher elevation. Still, an antenna on the window definitely helps versus mounted on the radio/scanner.

A better solution that may or may not work, due to the WifeFactor, is a larger antenna meant for outdoor use. A Diamond X30A is about 1.4 meters tall. It uses an artificial ground plane as part of its design. One could of course paint the antenna to match the indoor decor to reduce the WTF?! Is That! question. You may need to get creative with the placement, but even if it is not close to the window it would be an improvement over a rubber duck antenna.

Before you buy anything, are you not hearing something in particular? Basically, if you can hear what you want clearly with what you have why purchase anything? You even note, "That works..." regarding your current antenna setup, so why are you chasing this rabbit? The other side of the building you live in will probably block any simplex traffic. Again, with elevation it does not take much to receive repeater traffic.

I almost forgot, if your windows are treated and block RF try putting the antenna near an exterior wall and not the window. I have this issue at a workplace and my reception is much improved at the wall instead of the window.

 

[popnokick]

Here's something inexpensive and simple to try, but has worked for many who have posted their results here on RR: Use one of the inexpensive flat panel "blade" or "leaf" type HDTV antennas. TV antennas are close in frequency to most of what we want to hear on scanners, and broad enough in bandwidth to pick those signals up. You'll need an adapter to go from the male F-connector at the end of the antenna's cable to your scanner. Place it high in the highest window... or possibly on a wall... that faces the direction where most of what you want to hear comes from. You may need to turn it 90 degrees on its axis to change the polarization from horizontal to vertical. And move it about the window / wall (the antenna cable makes it simple to do that). These are directional antennas so the receiving area will be primarily in one direction... move the antenna about... just as you would a cellphone... to find the "hot spot" where it works best on the window or wall. The whole setup could cost as little as US$20 to try... what's to lose?

 

[Bob1955]

I live in a high-rise building in Melbourne (Australia) where external antennas are prohibited by "the rules" - which has meant that my SDS-100 was primarily just being fed by various handheld antennas. That works, but, I actually am looking for something that I can place in the window that maybe increases my UHF/VHF scanning reception.

I found a few inexpensive options on Amazon (Fosa 30MHz -1200MHz Wideband Scanner and another, similar "wire attached to window with suction cup" option) but realise that I can probably do better. These are working (surprisingly) well in the mean time.

Luckily, I've got floor to ceiling windows, and an incredible view out of them, but, I realise that on this side of the glass (+steel, +the rest) that I'll always lose a bit of signal.

I'm not doing any transmitting, just receiving, and mostly UFH/VHF ranges (not a lot of 800MHz active here), but I want something that does have some flexibility and isn't too restricted in its tuning, if possible.

I reckon that there are probably some mobile antennas (like the Larsen NMO150-450-800 Tri-Band) that may work well, but was wondering if there were other suggestions people had who had tried things out in a similar situation.

Thanks!

I would go with the Diamond SRH-77CA for the SMA connector on your SDS-100. That diamond antenna is the BEST going and quality too. You can purchase that on Amazon.co. Make sure you order it with the number I gave you, NOT the RH-77CA as that is with a BNC connector, then you would need to use the adaptor with you handheld scanner.
Hope this helps you out gdaykoloa.

 

[krokus]

Here's something inexpensive and simple to try, but has worked for many who have posted their results here on RR: Use one of the inexpensive flat panel "blade" or "leaf" type HDTV antennas. TV antennas are close in frequency to most of what we want to hear on scanners, and broad enough in bandwidth to pick those signals up. You'll need an adapter to go from the male F-connector at the end of the antenna's cable to your scanner.

In Oz, it would terminate in a PAL connector, most likely.

 

[wa8pyr]

There are a number of wideband antenna options for receivers. Have you considered a discone, for example? You could hang it from the ceiling somewhere inside, either “right side up” or “upside down”, and maybe even make it look like an interesting conversation piece in the process

There are small “mobile” ones like the the Diamond D220R and larger “base” ones like the Diamond D130J. If you don’t need the low end of reception below VHF, you can forgo the vertical whip and keep it more compact. Otherwise it’s hard to find a good wideband antenna that works well for all receive.

I'll second the vote for the small discone. A friend had one (if I recall correctly made either in Australia or the UK) and was not impressed with the performance until he discovered that the coax shield had somehow come undone from the connecting point. He fixed it and discovered all of a sudden that it enabled him to hear all kinds of stuff when it was sitting at a ground floor window. As you're on the upper floors it would probably work quite well.

I whipped one together once out of pieces of wire just for grins, and it seemed to work pretty well. . . until I dismantled it to use the parts elsewhere.

That being said, when I'm traveling I usually use a suction cup mount with a telescoping BNC whip attached to it. Stuck to the window of my hotel room it works quite well.