Hi all,
Just a simple question. The ambos and firies in tasmania use VHF, around 76-79Mhz and I know that when you have an antenna cut to specific freq it has 4mhz either side, I was thinking of having one of the antennas (pictured) cut to 78Mhz however this is the big question:
Is it better to get the 1/4 wave one at 96cm OR the the 1.5m one? I plan to use the antenna inside for the time being.
Thanks
78MHz Antenna question...
- robb
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78MHz Antenna question...
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Uniden UBCD996 + 396T, UBC9000XLT, Icom IC-RX7, Yaesu FT-60.
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Re: 78MHz Antenna question...
The longer one would generally have more gain.
Jeff (1000).
http://users.tpg.com.au/jeffnbel/SSTV-Highfields
http://users.tpg.com.au/jeffnbel/SSTV-Highfields
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Re: 78MHz Antenna question...
I personally would look for a dual band 144/470mhz ham radio antenna, it would harmonically drop to those freqs.
I used one in NZ for monitoring local fire on 76Mhz while monitoring police on 468mhz and pagers on 158mhz through a splitter
I used one in NZ for monitoring local fire on 76Mhz while monitoring police on 468mhz and pagers on 158mhz through a splitter
Cheers
BG
UBC9000XLT, UBCT8, BCT15X, UBC92XLT, Kenwood R-5000, PSR-410 , KG-UVD1P
BG
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Re: 78MHz Antenna question...
I initially thought that too, but if you can read the fine print, they both say Unity gain.hotmetal1000 wrote:The longer one would generally have more gain.
The short one is basically 1/4 wave at 78 Mhz in its present state, give or take a couple of millimetres.
As for the long one, given the 'gain' comments, it is hard to say what it is, when you consider the helical windings, but seeing it only covers 70 to 83 MHz, and you're only using it for receiving, I wouldn't bother cutting it at all.
As for which one to choose. Remember the saying: The more metal in the air, the better the signal.
--
Comint
- robb
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Re: 78MHz Antenna question...
Thanks, from the sounds of it - the longer the better and just curious why I would not want this cut to 78mhz? :sc
Happy scanning,
Uniden UBCD996 + 396T, UBC9000XLT, Icom IC-RX7, Yaesu FT-60.
Uniden UBCD996 + 396T, UBC9000XLT, Icom IC-RX7, Yaesu FT-60.
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Re: 78MHz Antenna question...
I did see that unity gain, as for what that is supposed to mean I don't know.
Jeff (1000).
http://users.tpg.com.au/jeffnbel/SSTV-Highfields
http://users.tpg.com.au/jeffnbel/SSTV-Highfields
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Re: 78MHz Antenna question...
You generally only cut these type of antennas to frequency, if they are to be used for transmitting.robb wrote:Thanks, from the sounds of it - the longer the better and just curious why I would not want this cut to 78mhz?
Unity Gain means 0db gain (or loss). In other words no Gain or Loss.hotmetal1000 wrote:I did see that unity gain, as for what that is supposed to mean I don't know.
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Re: 78MHz Antenna question...
Just done some research on unity gain for my own understanding, basically a unity gain antenna will transmit in all directions evenly including up and down.Comint wrote:You generally only cut these type of antennas to frequency, if they are to be used for transmitting.robb wrote:Thanks, from the sounds of it - the longer the better and just curious why I would not want this cut to 78mhz?
Unity Gain means 0db gain (or loss). In other words no Gain or Loss.hotmetal1000 wrote:I did see that unity gain, as for what that is supposed to mean I don't know.
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Jeff (1000).
http://users.tpg.com.au/jeffnbel/SSTV-Highfields
http://users.tpg.com.au/jeffnbel/SSTV-Highfields
- robb
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Re: 78MHz Antenna question...
Thanks for the help guys!
Happy scanning,
Uniden UBCD996 + 396T, UBC9000XLT, Icom IC-RX7, Yaesu FT-60.
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Re: 78MHz Antenna question...
this is a bit old ,,, but i use the RFI - Stainless mobile antennas , here in vic for RAV or AV as they are now known and no problems i will get the details for you
John Remington
VK3 XRI
South Eastern Communications
Radios-Communications- Pagers
facebook- https://www.facebook.com/pages/South-Ea ... 183?ref=hl
http://www.secomms.com.au
sales@secomms.com.au
0434720006
VK3 XRI
South Eastern Communications
Radios-Communications- Pagers
facebook- https://www.facebook.com/pages/South-Ea ... 183?ref=hl
http://www.secomms.com.au
sales@secomms.com.au
0434720006