Multi band antenna question

[nyscan00]

Hi Im looking to buy a Multi band scanenr antenna that will reieve 45.00mhz all the way trhough 900mhz. I was looking for a base version that I could mount on a mast. Ive looked at discones and similars ...what does everyone recommend? I would like to get a multi band antenna that looks like my CB antenna ( 1 straight mast about 12ft tall)

Do they make multi band antennas similar to large CB base antennas?

Thanks in advance-

 

[K2KOH]

I use the Radio Shack discone with the low band vertical element, and have no problem listening to just about everything in Dutchess County and the surrounding counties. I can also pick up two of the trunking towers for Connecticut State Police.
You're going to get a lot of recommendations for different types of antennas, but I swear by the discone for wideband receive.

 

[loumaag]

I agree with Kieran, for what you are looking for, a discone will do the trick; however, I recommend buying something other than the Radio Shack model. Electrically it is the same as any other discone (for the same frequency specs) but its construction is pretty poor. Especially in the cone area. The attachement method is prone to breakage in any inclement weather due to the stress on the threads. (Personal experience.) It is not worth the amount of money they want for it; spend another $20 and get a real one like a Diamond. :wink:

 

[crayon]

The attachement method is prone to breakage in any inclement weather due to the stress on the threads, or having the mast that you mounted it on be blown over because it was not guyed and only sticking in a trashcan filled with bricks. (Personal experience too.)

 

[K2KOH]

I have to disagree about the discone from RS getting destroyed in windy weather. I've had some pretty good sustained winds up here, and my discone has lasted for a few years. Maybe I'm just lucky

 

[loumaag]

I have to disagree about the discone from RS getting destroyed in windy weather. I've had some pretty good sustained winds up here, and my discone has lasted for a few years. Maybe I'm just lucky

You are indeed lucky. Mine lasted less than 6 weeks before I lost 3 of the cone radials. No inclement weather other than sustained winds. (The first one broke off after being in the air for 8 days.)

When I replaced it with a "real" one I saw the same failure on each of the 3 that fell off (and I recovered), the steel threads broke off near where they are pressed into the end of the hollow aluminum radial. Now the Diamond uses a completely differnt approach, first the radials are solid aluminum rods, noched near the end that installs into the base of the antenna. They are held in place with allen screws which actually "bite" into the aluminum and will not come loose.

As I said, it is worth the extra $20 to have a quality product. RS has a good scanner antenna (20-176 VHF-Hi/UHF) which I use as both a scanner antenna and a portable 2m/70cm antenna, but the discone is really poorly constructed.

 

[DXKW]

ANTENNA QUESTION

I HAVE THE DIAMOND ITS A WELL BUILT ANTENNA I WAS AT RADIO SHACK LAST WEEK AND THEY SAID THEY HAVE NOT SOLD THE DISCONE
FOR FOUR YEARS I DONT KNOW ITS TO BAD CHANNEL MASTER STOPPED
MAKING THE 5094 DISCONES ARE BROAD BAND BUT HAVE NO GAIN.






THANKS
DXKW

 

[loumaag]

Re: ANTENNA QUESTION

... I WAS AT RADIO SHACK LAST WEEK AND THEY SAID THEY HAVE NOT SOLD THE DISCONE FOR FOUR YEARS...

Hmmm, once again, you have questions, they don't have correct answers. Product #20-043 is indeed alive and for sale. :?

 

[DXKW]

ANTENNAS

YOU POSTED THAT WHEN I WENT TO THEIR WEBSITE TO DOUBLE CHECK
YOUR RIGHT THEY STILL SELL THE DISCONE THEY HAVE TWO STORES IN THIS AREA AND I GET DIFFERENT ANSWERS TO THE SAME QUESTION
BETWEEN THE TWO IM ABOUT READY TO GIVE UP ON THEM.






THANKS
DXKW

 

[Pro-95]

Re: ANTENNA QUESTION

Hmmm, once again, you have questions, they don't have correct answers. Product #20-043 is indeed alive and for sale. :?

This >>>one<<< works as well, if not better, plus doesn't have a plastic/metal joint to break. And you can buy three of them for the price of the other discone.

O/T:Still like my $12 dollar J-poles.

 

[loumaag]

Mike, you are right. The VHF-Hi/UHF antenna works great (as I said up the thread) but it doesn't work for well for above UHF like at 800, 900, or 1200 MHz (despite the advertising claims.) But for VHF/UHF, I love it. BTW, if people wouldn't try to tighten the vertical radiator on the discone with anything other than their hands it wouldn't have a problem with the plastic/metal joint. The real problem is the actual construction of the cheap hollow tube cone radials and disk capacitance hat. The 20-176, you will note, uses solid rods as opposed to hollow tubes. BTW I own several 20-176's and even have one sitting here next to the desk still in the shrink wrap waiting for me to figure out what else I can use it for. :wink:

 

[SAR923]

Maybe there were changes in the RS discone construction at some point. I've had mine up for a year with no problems. All the radials are solid screw joints and I used a little Loctite on each one when assembling. It has remained solid for me and we've had some 50-60 mph winds here. The one caution I'd make is that you should stick with the 20-176 VHF/UHF antenna if there's no 800 mHz activity in your area. The discone is much worse with high band VHF than the 20-176. For 800 mHz, it's superb.

 

[okla-lawman]

Check with austin antenna they make some that look like a cb antenna other wise try diamond or comet

 

[nyscan00]

ok thanks for all the replies and info
I will look into discone antennas

One more question:
I was looking at a procomm multi band antenna
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=40980&item=5714634862&rd=1
does this antenna look ok for multi band coverage? has anyone tried this and if so what were your thoughts / results


Thanks again

 

[Voyager]

ok thanks for all the replies and info
I will look into discone antennas

I recently put up a Discone antenna. I found its performance pipiful compared to the antennas I'm used to (ground plane tri-element, full length side mount, and various ham and commercial antennas). I thought this must just be the model I have put up (I have two models, three antennas total, but have only put up the one thus far, and it HAS the low band vertical element), but a friend of mine has two of the Radio Shack models. I QUITE LITERALLY found that I RECEIVED MORE on the rubber duck that came with my PRO-96 than I did with his two discones. Signals that were noisey were fully quieted on the rubber duck. His discones are fed with about 30 feet of RG-8X (not a lot of loss), and mine was fed with about 20' of Heliax (VERY low loss). I am extremely surprised that the discone performance is as poor as it is. I haven't tested it for transmitting yet, and it may well resonnate well across a wide range, but so does a dummmy load. That doesn't mean it's a good antenna.

I've found that a simple Cushcraft Ringo Ranger II (ARX-2B) 2M ham antenna works much better - even on low band. I honestly haven't tested its performance on 800, but on LB, HB, and UHF, the ringo can't hold a candle to it. If you're not using it for transmitting, the SWR won't matter. As I said above, my dummy load is flat everywhere, too. But, there is a difference between loading and radiating (or abosorbing/receiving) signals.

I don't have much experience with the type, but also read up on PRO-95's J-pole project. I highly suspect they, too, will put the discone to shame.

As for the one you mentioned, it looks like nothing more than a small VHF quarter wave antenna with RG-174 (not great specs, but only 12' - then again, that is still a 7 dB loss at 800 MHz!) and a BNC (one of the better connectors for 800 MHz). I've used a broadband Motorola VHF quarter wave with adequate results - even on low band - on a scanner, so that antenna may not work too bad (but again, note the 800 MHz loss - I used RG-58 ).

Joe M.

 

[ka2mek]

The attachement method is prone to breakage in any inclement weather due to the stress on the threads, or having the mast that you mounted it on be blown over because it was not guyed and only sticking in a trashcan filled with bricks. (Personal experience too.)

When working with or on any antenna installation for the home,Safetyis the KEY word.The entire installation needs to be planned out properly to eliminate any hazard to humans or property.The above method described is VERY unwise and may be prone to damaging the antenna and the area surrounding it.Also always be aware of over head power lines and other service lines coming near the antenna.Many people have been injured or killed by attempting a less than 100% solid sturdy installation of antennas from small homemade works of art to large tower supported structures.In regards to the DISCONE antenna it is a tried and true WIDE BAND performer that is also widely used in military installation.The Radio Shack or any other brand Discone if properly assembled and installed will give years of fine performance thru any type of weather situation and its frequency range is ideal for scanner monitoring.I have used one for years and also have homebrewed a few for expierimentation and have found them to deliver flawsless enjoyment across a wide range of frequencies.
Hope this helps you nyscan00.By the way I live on the ocean near Sandy Hook NJ and can copy the low band fire radio frequencies from Rockland and Westchester County NY here with the Discone and I am shure that AEMTKieran would agree that is a substantial distance indeed.But Above all safety will always be the PARAMOUNT issue in the Installation of any type of home Antenna System.
73
Robert-KA2MEK

 

[Pro-95]

Oh sure post a picture like that. Don't you realize that I'm easily influenced.

Yes, I'm suffering from Arecibo envy.

 

[jerneedog]

Re: ANTENNA QUESTION

This >>>one<<< works as well, if not better, plus doesn't have a plastic/metal joint to break. And you can buy three of them for the price of the other discone.

That's the one I am currently using, but it's not setup outside just yet.
Still trying to figure out where and what type of mounting I'm going to do.
Until then...it's just set up on my book shelf in my office.
I would like to buy at least one more of those and set them both up to use with one scanner.

 

[ka2mek]

Oh sure post a picture like that. Don't you realize that I'm easily influenced.

Yes, I'm suffering from Arecibo envy.

Ah...Arecibo!in Puerto Rico.
I like you pro,YOU always make me laff!
Speaking of which(Arecibo)The father of "The Big Ear" just became a silent key recently..........W8JK

http://www.arrl.org/news/stories/2004/07/21/1/

Thought you might like to read that PRO,So I posted the link to share with one and all.
73!
Rob-KA2MEK

 

[doctordave]

Somewhat related topic:

I have tweaked my SCANTENNA for optimal performance on 39 MHZ.....is there any real advantage to instead using a ground plane antenna (cut for 39 MHZ) -vs- a SCANTENNA cut for this freq? Looking for improving my range on some distant stations. Perhaps yet another antenna design would be ideal? In any case, the antenna will be attic mounted.

Appreciate any input.

Thanks.

Dave