Looking for help with antenna

[enchantingbeetroot]

Hello,
I recently bought an SDS 100 and almost immediately started looking for a replacement antenna. I ended up going with the Remtronix 842-S. It works ok, but I am looking to cut out some of the static. I have little experience with antennas and would like to ask for help in choosing the right one for my area. Any help is appreciated. Thank you for your time and suggestions. I am trying to monitor Lincoln County, Sagadahoc County, Cumberland County and Androscoggin County. all in Maine.

 

[enchantingbeetroot]

Since it's Inevitable that I get this comment from someone, I need to mention that I have the squelch set on 2 which is good for most channels but the static is still very present.

 

[prcguy]

It’s doubtful you will get any better range using another antenna mounted on the scanner. An antenna outdoors on the roof in the clear of obstructions fed with low loss coax will definitely increase your range.

 

[enchantingbeetroot]

Thanks for the fast reply! Do you have an antenna preference? I’m not too good at selecting decent ones yet lol

 

[prcguy]

Thanks for the fast reply! Do you have an antenna preference? I’m not too good at selecting decent ones yet lol

What frequencies do you listen to most?

 

[tbzep]

I use homemade offset dipole antennae on my scanners at home. Simple to make with 2 wires and a balun. I have one stuck in the window with one of the wife's suction cup hooks for the scanner I have by the couch. In the cave, I just stick them up on the wall with a sewing pin. It makes a big difference in fringe reception transmissions.

Homebrewed Off-Center Fed Dipole - The RadioReference Wiki

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[Enforcer52]

I use homemade offset dipole antennae on my scanners at home. Simple to make with 2 wires and a balun. I have one stuck in the window with one of the wife's suction cup hooks for the scanner I have by the couch. In the cave, I just stick them up on the wall with a sewing pin. It makes a big difference in fringe reception transmissions.

Homebrewed Off-Center Fed Dipole - The RadioReference Wiki

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Checked the above homebrewed antenna wiki, does anyone know what freqs its is tuned to?

 

[prcguy]

Checked the above homebrewed antenna wiki, does anyone know what freqs its is tuned to?

I did some calculations and it appears the Wiki antenna fundamental resonant frequency is 85Mhz (1/2 wavelength at 85MHz is 66in) then it will also resonate on most harmonic bands like 170, 255, 340, 425, 510, 595, 680, 765 and 850MHz before getting out of range of the balun. Basically it doesn't work very many places that are useful.

Another problem is when hung vertically it will radiate at the horizon like a 1/2 wave dipole only at its fundamental frequency of 85MHz then it will have more and more gain lobes and nulls pointing up and down going up in frequency but not anything useful at the horizon. Its basically the same as an 80m or 40m OCFD used on HF but those are always horizontal and work fine like that on HF making a great NVIS on 80 and 40m then they radiate off the sides and end on higher bands. If you were to hang the HF version vertical it would have the same problem and become a poor performer on all bands except the fundamental. For these reasons I think the inventor of the RadioReference Homebrewed Off-Center Fed Dipole didn't know what they were doing and made a stupid design.

I would not wase my time making one of these things and even if you scaled it to actually resonate somewhere useful it will still have lobes and nulls away from the horizon wasting any gain at the clouds or in the dirt. Did I mention its a stupid design? Why is it still in the RR Wiki?

 

[Enforcer52]

Thanks for the info, put that one in the trash bin!

 

[popnokick]

To get some wideband coverage it’s better than the telescoping whip that comes with the scanner and better than a paper clip. Might worsen simulcast issues by supplying too much signal. And it is an expensive investment of valuable time and resources (about $20 and 20 mins to make it). So go out and throw some real money at the antenna requirements! Get something that doesn’t roll up in and travel in a suitcase, or something that will attract attention from your spouse… and maybe poke your eye out. And doesn’t use that crappy RG6 coax 🙄

 

[tbzep]

Did I mention its a stupid design? Why is it still in the RR Wiki?

I can tell you why. Regardless of your calculations, it performs much better in real life than every OEM rubber ducky antenna and telescoping antenna on my scanners. I listen to VHF in the aircraft band, 154-156, and in UHF in the 453-460 range. I can't comment on 800 performance. I use my duty radios for the stuff that is only broadcast digitally. It also costs nothing if you already have a balun and some scrap wire.

 

[prcguy]

I can tell you why. Regardless of your calculations, it performs much better in real life than every OEM rubber ducky antenna and telescoping antenna on my scanners. I listen to VHF in the aircraft band, 154-156, and in UHF in the 453-460 range. I can't comment on 800 performance. I use my duty radios for the stuff that is only broadcast digitally. It also costs nothing if you already have a balun and some scrap wire.

It should be better than a rubber duckie or telescopic in most cases but probably not be better than the old radio shack 20-176 ground plane on the VHF/UHF/800 public service bands. I would rather see people make something that is properly designed and works better.

If you were going to make an offset center fed scanner antenna, not counting over most of its frequency range it will point up in the sky and down at the ground, you might consider one 12ft long fed at the 4ft point with a TV balun. That should resonate as a full half wave at 39MHz (CHP?) then 117MHz at the lower end of VHF air, then 156, 468, 780 and 858MHz public service bands plus a bunch of others.

I would think a trapped vertical over ground plane could be made repeatable as a project using off the shelf inductors and capacitors. Or three vertical elements configured coaxially for VHF, UHF and 800. Don't make me design a multiband scanner antenna for the RR Wiki that actually works......

 

[tbzep]

It should be better than a rubber duckie or telescopic in most cases but probably not be better than the old radio shack 20-176 ground plane on the VHF/UHF/800 public service bands. I would rather see people make something that is properly designed and works better.

If you were going to make an offset center fed scanner antenna, not counting over most of its frequency range it will point up in the sky and down at the ground, you might consider one 12ft long fed at the 4ft point with a TV balun. That should resonate as a full half wave at 39MHz (CHP?) then 117MHz at the lower end of VHF air, then 156, 468, 780 and 858MHz public service bands plus a bunch of others.

I would think a trapped vertical over ground plane could be made repeatable as a project using off the shelf inductors and capacitors. Or three vertical elements configured coaxially for VHF, UHF and 800. Don't make me design a multiband scanner antenna for the RR Wiki that actually works......

 

[tbzep]

Those numbers don't resonate where I listen, so it wouldn't be all that much better for me, plus, I don't need more performance than what these little things give me. As for making you design a multi band antenna, I wish you would! 😎 But we must have design rules for it to be used in place of this little OVFD: It has to be super cheap, parts available in your junk drawer and/or hanging on a nail in the shop, and when deployed it must fit inside your attic or in the window behind the curtains to keep the wifey off one's back. That's what makes this little antenna useful. No cheating with outdoor masts!

I pick up VHF EMS/Fire in a town that is 55 miles away with one of these nearly all the time, and get a couple towns' VHF Fire 24/7 which are about 30-35 miles. I'd get a lot more, but I'm using them on analog scanners. Without these little things, my local stuff even has static.