BUILDING A NOOA ANTENNA?

[turbosat]

I think I know what connector you want, radio shack calls it an rca, I think. Just a straight connector that shoves into the receiver/scanner. Old school-like the old bearcat scanners had back in the 70's. They do have the adapter at RS, will mate to a regular rg6 connector.

 

[MikeinBaja]

I think I know what connector you want, radio shack calls it an rca, I think. Just a straight connector that shoves into the receiver/scanner. Old school-like the old bearcat scanners had back in the 70's. They do have the adapter at RS, will mate to a regular rg6 connector.

Went to Rat Shack today and bought 3 different sizes that were close; 2 are too small & 1 is too big - but not by much.

Going to grind down the one that is a little too bit big this weekend and MAKE it fit and then solder it on.

Meanwhile, the "alien LEM" antenna sits waiting for a mate.

What a frustrating deal this has been!

 

[turbosat]

Yep sounds frustrating. Maybe take the receiver into the RS store for a perfect fit?? But they may not have it, sometimes you run into oddball connectors like that. Hope you get it rigged up soon, curious to see how that antenna works out.

 

[MikeinBaja]

ANTENNA-STEIN LIVES!

Finally got the connector combination to work after a few hours of futsing around on the bench, and as ugly as it is, reception is clear as a bell.

Unit locked on right away onto the NOAA channels as well as the atomic clock out of CO.

I did figure out the mount and how to insulate - piece of 2X4 laid flat & screwed catty-corner (between the legs) to the underside of the base plate, then a "U" clamp to the pole. Mounted it on a ground pole (not where it will live) and reception did not change.

Now that I know it works and proved the concept, I'll start on building a permanent one (that will look better too!).

Thanks for all the help, diagrams & pictures!

 

[turbosat]

HAHA< thats great Mike, I'm glad it worked out. I'm not too much of a builder but putting that first ground plane together and having it work so well was a great feeling. I like the look of that one you came up with though, its unique!
Even if it does resemble the Mars Rover, lol.

 

[MikeinBaja]

HAHA< thats great Mike, I'm glad it worked out. I'm not too much of a builder but putting that first ground plane together and having it work so well was a great feeling. I like the look of that one you came up with though, its unique!
Even if it does resemble the Mars Rover, lol.

Thanks for all your help with a project that was well out of my tech comfort zone.

What - you thought it was ugly? I was gonna submit it to NASA and charge them a skillion $ and split it with you!

Seriously, I've always been a fabricator and I learned a great deal putting this first one together.

Thanks again for the help - watch this space for "LEM II". It will be more robust and "prettier".

BTW - got those solid locks less than 3' off the ground.

 

[JerseyMatt]

ANTENNA-STEIN LIVES!

Finally got the connector combination to work after a few hours of futsing around on the bench, and as ugly as it is, reception is clear as a bell.

Unit locked on right away onto the NOAA channels as well as the atomic clock out of CO.

I did figure out the mount and how to insulate - piece of 2X4 laid flat & screwed catty-corner (between the legs) to the underside of the base plate, then a "U" clamp to the pole. Mounted it on a ground pole (not where it will live) and reception did not change.

Now that I know it works and proved the concept, I'll start on building a permanent one (that will look better too!).

Thanks for all the help, diagrams & pictures!

Hey, I just noticed this topic.. I'm definitely not one to put someone down for tinkering, I'm a ham and love building antennas. I like the design and best of all it didn't cost anything.. But just wanted to let you know before you start spending on materials for a 'permanent' one, Radioshack has one that works very well for $20. It's designed for FM (and that's what I originally bought it for), but I have my weather radios hooked to it as well and they come in crystal clear. 'Tuning' the element length to the frequency isn't anywhere near as crucial for general reception along the same part of a band (mid-VHF in this case) as it is for transmitting.

So just keep that in mind when you're pricing out material..

 

[MikeinBaja]

I actually did come across that one while doing initial research. Problem is, it is out of stock on the web & none of the SOCAL stores have them in stock either.

That's one of the main reasons I decided to build one, but I do appreciate reference!

 

[turbosat]

JerseyMatt I had one of those several years ago, but back then I never thought of it as useful for anything other than FM radio. Since I got back into scanning about a year ago, I've built several different types of antennas, you are right-it is fun tinkering. Almost as much fun as playing with these fta satellite dishes! That is a good tip on that antenna , for omnidirectiional use.

 

[Cham]

I found the best antenna for NOAA/WeatherRadio is a J-pole, easy to make with 300 ohm twin-lead. Doesn't require ground radials so it is easy to hide in a plastic radome for that "professional" look. Can also hang on the wall or from a curtain rod close to your receiver to minimize feedline losses... Just google J-Pole antenna and there are several calculators that you can use for finding dimensions...
I made one and it hangs behind the curtain in the bedroom. I use my WeatherRadio for an alarm clock, Think the model is a WR-300 from Midland and uses an audio connector as the RF in jack. I just use 2ft piece of coaxial audio cable as the feedline. Works great except when we get an inversion on VHF as there is another station about 100mi away that interferes!
-C.

 

[MikeinBaja]

I found the best antenna for NOAA/WeatherRadio is a J-pole, easy to make with 300 ohm twin-lead. Doesn't require ground radials so it is easy to hide in a plastic radome for that "professional" look. Can also hang on the wall or from a curtain rod close to your receiver to minimize feedline losses... Just google J-Pole antenna and there are several calculators that you can use for finding dimensions...
I made one and it hangs behind the curtain in the bedroom. I use my WeatherRadio for an alarm clock, Think the model is a WR-300 from Midland and uses an audio connector as the RF in jack. I just use 2ft piece of coaxial audio cable as the feedline. Works great except when we get an inversion on VHF as there is another station about 100mi away that interferes!
-C.

Thanks for the tip - the ones I've googled are made from copper pipe (which I have) and they sure look sturdier than what I was looking to do.

Great recommendation!

 

[Cham]

Yes the copper pipe ones are most common, bit obtrusive for the bedroom or living room
If you use the 300 ohm line type the thin conductors narrow down the passband a bit and helps filter out out-of-band rf that might overload the weather radio receiver. Remember to change the dimensions slightly for the shorter wavelength compared to the ham 2m band.. I suppose one of these antennas with a good feedline would work well as a marine band antenna too...
-C.

 

[MikeinBaja]

Yes the copper pipe ones are most common, bit obtrusive for the bedroom or living room
If you use the 300 ohm line type the thin conductors narrow down the passband a bit and helps filter out out-of-band rf that might overload the weather radio receiver. Remember to change the dimensions slightly for the shorter wavelength compared to the ham 2m band.. I suppose one of these antennas with a good feedline would work well as a marine band antenna too...
-C.

Well, I used the on-line dimension calculator set to 162.475MHz (middle of the NOAA range) built it exactly to specs - and it didn't work worth a darn. Even tried moving it around and on top of a big ladder. The 1/4 wave ground plane (Antenna-Stein) worked great in the same spot.

Went over all the calculations again, measurements and all solder points - no joy. Plugged in the 1/4 wave using the same line and it worked just fine.

Now I'm really confused!

 

[turbosat]

Mike, did you have the j-pole grounded? I built a couple of those with 1/2" (price=OUCH) and they work very well. Mostly I made them for comparison with those ground plane antennas, all the reviews I read about them said the ground plane would beat them hands down. But I found out, mine work as well as, or better than the ground planes. I cut one for 128.000 aircraft band, and it blasts signal to my scanner! Even picks up the 155 vhf police band-range very well also. "The other one I cut stricly for 155mhz police band, it also works very well , even up to the weather radio freqs. But they have to be grounded. I pipe-clamped mine to legs of my tv tower, so the metal-to-metal contact must be enough for mine to work right.

 

[MikeinBaja]

Mike, did you have the j-pole grounded? I built a couple of those with 1/2" (price=OUCH) and they work very well. Mostly I made them for comparison with those ground plane antennas, all the reviews I read about them said the ground plane would beat them hands down. But I found out, mine work as well as, or better than the ground planes. I cut one for 128.000 aircraft band, and it blasts signal to my scanner! Even picks up the 155 vhf police band-range very well also. "The other one I cut stricly for 155mhz police band, it also works very well , even up to the weather radio freqs. But they have to be grounded. I pipe-clamped mine to legs of my tv tower, so the metal-to-metal contact must be enough for mine to work right.

Never thought about the grounding - I was just holding it up in the air with my hands.

Won't be able to test that until tomorrow.

I'll give it a try and let you know!

 

[turbosat]

I think you'll find that the grounding is key. All those on-line project webpages I saw said to fasten the copper jpole to a metal mast, and if the mast wasn't grounded, to run a wire to ground from the antenna. Mine don't have a ground wire, but the tv tower is in the ground in concrete so it must be enough.

 

[MikeinBaja]

I didn't get back to this yet & we are leaving for 8 days tomorrow - will get back on it when we return.