RadioDaze
Member
Please tell me if I've misunderstood or overlooked anything...
I need to make a really stealthy, easy-up, easy-down antenna. Very strict condo. I’ll put it up when I need it, particularly at night, and I want something that doesn’t rely on a ground plane or counter-poise. I figure a 1/2 wave to 5/8 wave antenna will solve that, so I’m considering the Diamond NR73 models Diamond® Antenna ~ NR73BNMO Dualband Mobile Antenna or NR770 models Diamond® Antenna ~ NR770HBNMO Dualband Mobile Antenna which are half wave at VHF and 5/8 at UHF. I would just stick it on a mount at the end of a pole, either PVC or (more likely) aluminum. Just 6 or 7 feet, maybe less, to clear the rain gutter. I’d use about 25 ft. of LMR 240 Ultra.
Does it sound like I’m on the right track for a non-grounded antenna?
My primary frequency target is centered right around 495MHz, 20 MHz width, for LAPD, P25, about 30 miles to the northwest. Half of their freqs are around 484 MHz, the other half around 506 MHz. I can get some of it indoors with a rubber duck, with a lot of bad decoding on many channels, and with a mag mount on the balcony rail, I do a little better. The roof covers my balcony to a point about 10 inches past the rail, so I’ll make a bracket to hold the pole out a foot or so past the rail. I just want to get the base of the antenna above the gutter. I’m on the top floor of a 3-story building. The roof slopes upward, in the direction I want to receive, to a point about 7 or 8 feet higher that the gutter, and there’s no hope of getting above that. Stealth is key, and I want this thing noticed as infrequently as possible. There is MUCH better reception of my target freq on the other side of the building.
Other comments: It would be nice to be able to TX at 2 meters and 440, hence the dual-band antenna.
My 800 MHz reception is already good - I could use a paper clip to pick up my local TRS. This thing should be lightweight. Attic antenna: no way - the roof has metal flashing overall. Sealed like a can of Spam. I did consider a small yagi, but I think I'll be too close to the roof.
EDIT - seeing a few bad reviews on the Diamond, maybe this Maldol would be better: http://www.eham.net/reviews/detail/4378
I'm wide open to suggestions.
I need to make a really stealthy, easy-up, easy-down antenna. Very strict condo. I’ll put it up when I need it, particularly at night, and I want something that doesn’t rely on a ground plane or counter-poise. I figure a 1/2 wave to 5/8 wave antenna will solve that, so I’m considering the Diamond NR73 models Diamond® Antenna ~ NR73BNMO Dualband Mobile Antenna or NR770 models Diamond® Antenna ~ NR770HBNMO Dualband Mobile Antenna which are half wave at VHF and 5/8 at UHF. I would just stick it on a mount at the end of a pole, either PVC or (more likely) aluminum. Just 6 or 7 feet, maybe less, to clear the rain gutter. I’d use about 25 ft. of LMR 240 Ultra.
Does it sound like I’m on the right track for a non-grounded antenna?
My primary frequency target is centered right around 495MHz, 20 MHz width, for LAPD, P25, about 30 miles to the northwest. Half of their freqs are around 484 MHz, the other half around 506 MHz. I can get some of it indoors with a rubber duck, with a lot of bad decoding on many channels, and with a mag mount on the balcony rail, I do a little better. The roof covers my balcony to a point about 10 inches past the rail, so I’ll make a bracket to hold the pole out a foot or so past the rail. I just want to get the base of the antenna above the gutter. I’m on the top floor of a 3-story building. The roof slopes upward, in the direction I want to receive, to a point about 7 or 8 feet higher that the gutter, and there’s no hope of getting above that. Stealth is key, and I want this thing noticed as infrequently as possible. There is MUCH better reception of my target freq on the other side of the building.
Other comments: It would be nice to be able to TX at 2 meters and 440, hence the dual-band antenna.
My 800 MHz reception is already good - I could use a paper clip to pick up my local TRS. This thing should be lightweight. Attic antenna: no way - the roof has metal flashing overall. Sealed like a can of Spam. I did consider a small yagi, but I think I'll be too close to the roof.
EDIT - seeing a few bad reviews on the Diamond, maybe this Maldol would be better: http://www.eham.net/reviews/detail/4378
I'm wide open to suggestions.
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