Antenna

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Re: Antenna

Postby bigpimp347 » Sun Aug 20, 2017 10:57 am

avoid a discone, all they are are un resonant lengths of wire you could use a coat hanger and pick up as well..

if you want VHF and UHF many ham antennas will work as these are designed to be resonant in these areas..
airband is just outside these bands but not by much and for receiving they work great..

X-30 or X-50 ideal for local 30 mile stuff..
X-200/300 for greater reception,
X-510 if you think gain answers all your questions and you have a good filtered front end..

me personally use an X-50 and even an X-300 get to hear some great distance without too move overload from local pagers and such..
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Re: Antenna

Postby m0lsx » Sun Aug 20, 2017 11:07 am

bigpimp347 wrote:avoid a discone, all they are are un resonant lengths of wire you could use a coat hanger and pick up as well..

if you want VHF and UHF many ham antennas will work as these are designed to be resonant in these areas..
airband is just outside these bands but not by much and for receiving they work great..

X-30 or X-50 ideal for local 30 mile stuff..
X-200/300 for greater reception,
X-510 if you think gain answers all your questions and you have a good filtered front end..

me personally use an X-50 and even an X-300 get to hear some great distance without too move overload from local pagers and such..


Every length of wire/metal is resonant at various frequencies, so a discone is a resonant antenna. Just not at a specified frequency like with a amateur radio antenna.
You are right about a amateur radio antenna being ideal if you want to listen to amateur bands. HOWEVER, the higher the gain, the narrower the band of low VSWR. So a high gain amateur radio antenna, is not as good on PMR, marine & airband for example as low gain amateur radio antenna, or a antenna designed for those bands.
The advantage with a well designed discone is that it is wide band antenna & offers a listener a good compromise over a series of band specific antennas. Although, to be fair a lot of antennas sold as discones are little more than a mobile whip antenna & some counterpoises & thus NOT a discone.
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Re: Antenna

Postby Mark5R » Sun Aug 20, 2017 11:29 am

I agree for VHF and UHF a ham 'white stick' is a lot better and not just an improvement but a hell of a lot better it brings VHF and UHF stations in clear that the discone wont even hear with the squelch open. when I say VHF and UHF I mean VHF around 110 - 173MHz and UHF around 410 - 460MHz.

I do find the discone performs better below 110MHz than the white stick especially on the low ch freqs around CB and old phone freqs and 66-88MHz. Commercial radio 88-110 band about on par on both antennas. Mil band for me is better on the discone too but only slightly.
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Re: Antenna

Postby bigpimp347 » Sun Aug 20, 2017 5:31 pm

suppose it all depends on the discone as well,
some with the tuneible vertical section are poor compared to a white stick..

and my point on the white stick notice i did say the higher the gain the pointless they are..
a X-30 X50 are ideal scanner antennas, and lets also remember at VHF and mostly UHF everything is line of sight,
so you will usually only receive what you can see 20 up to 30 or so miles..
a discone is resonant on something i agree, not sure what..

but how many of you have actually put a white stick on an analyser ?? you'll be surprised where they resonate..
i did a test once with a discone and a white stick for resonance and the white sticks are fair better..

and scanner designed white sticks ??
nothing more than a couple of bits of ribbon cable in a plastic tube..
you'd be better of building simple dipoles from one feed for say 28mhz and the harmonic frequency is 6mtrs, then VHF and then UHF, but on VHF the gain is such they are not as sensitive,
so build a dipole for 10mtrs and 2mtrs and have a 1/4 on 10mtrs 1/2 on 6mtrs 1/4 on VHF and 3/4 on UHF and plenty in between..
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Re: Antenna

Postby m0lsx » Sun Aug 20, 2017 7:27 pm

My personal choice is a white stick over a discone. But it does depend upon what you listen to & where you are. I have a three band antenna up, but I am thinking about changing that as I only use the 6 meter part on TX & that would be better suited to a horizontal antenna.
For me the biggest advantage of a white stick over a discone is height.
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Re: Antenna

Postby G4RMT » Sun Aug 20, 2017 7:31 pm

All I can say is that here I have a white stick (an X30) and a discone. The discone is fractionally lower, and performs better than the white stick in the UHF air band. Connected to a scanner it is a little worse on marine band and the 2m band is much better on the X30. However - letting the scanner look through the air to air frequencies over the wash - maybe 80 miles away, the difference is pretty obvious - the white stick is deaf on many of the frequencies in use - switching between the two with a coax switch leaves me in NO DOUBT WHATSOEVER that the discone is a better antenna for mil airband. Even 1.5m or so lower, the difference is obvious. On UHF and VHF ham bands, the X30 is better - but it has gain compared to the discone on these bands.

If you are totally uninterested in UHF Military airband, then the white stick wins. If you are interested, then the choice is obvious.
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Re: Antenna

Postby alank950 » Wed Aug 23, 2017 3:21 pm

I am fitting one of these to a six foot pole fixed to a clothes line Scanmaster B1300 eBay item number:381377733360
.whats the know on these ..I havent bought it yet so i am open to suggestions..
...............................................................................................

spec below


Scanmaster B1300

Wideband base scanner antenna

Our top selling base scanner antenna, the B1300 is a favourite because it won't frighten the neighbours at only just over 1m in length, works very well over a wide 25-1300 Mhz bandwidth, and comes supplied with fittings ready to clamp to a short mast/pole, the fibreglass construction ensures a long life too!

Ideal for receiving Marine, Civil Aircraft, Amateur Radio, P.M.R. plus many more public services. Manufactured to the highest standard using good quality fibreglass, stainless steel and heavily chromed brass. Superb performance with maximum durability in all weathers. Complete with stainless steel mounting pole and clamps.

Scanmaster B-1300: Wideband base antenna
Frequency coverage: Typical 25 -1300Mhz
Construction: Fibreglass finish for long life
Length: 1.1m
Connector: High quality low loss 'N' type
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Re: Antenna

Postby G4RMT » Wed Aug 23, 2017 8:42 pm

I can't say for certain, but many of these types are simply ¼ wavelengths of wire, with common bottom connection - with one per band - so one for airband, one for low VHF, one for high VHF, one for middle UHF air band and one for UHF. They work like a simple ¼ wave on each band. I've got a similar one in the store here, but it's not up in the sky with the others. Draw a conclusion if you wish.
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Re: Antenna

Postby Shambles » Thu Aug 24, 2017 7:07 pm

HELP NEEDED PLEASE,I decided to purchase the Diamond D-3000N Antenna,I had some mast tubes from my previous scanner days,as I live in a bungalow height is not easy to get,the mast tubes are 34mm OD x 28mm ID I cannot get any height without the tube moving from side to side with it being top heavy,I use a 12ins x12ins bracket with Rawl Bolts into the brick work,the bracket is almost to the top of the gable end,any help would be much appreciated

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Re: Antenna

Postby m0lsx » Thu Aug 24, 2017 7:35 pm

What type of bracket are you using? A light weight TV bracket is no good, due to the pressures put onto them.
My own personal experience is that a pole needs a double bracket. Something like a T K bracket or a double chimney mount..

Image

Image

The top bracket is the one that takes the weight so you will see that the top bracket on the TK is the heaviest duty. The bottom balances, so is the lighter duty.
My highest bracket is an old fashioned 3 point one, that allows a low pole to be used. My lower pole is a T K & has my heavest antenna on.
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