My second Midland 6 dB Gain Antenna has broken above the coil on the antenna on my Jeep. The first one broke as I hit a tree branch with it and it weakened (I have it mounted high, on a heavy-duty wind faring). I don’t know what happened to this one, other than we get high winds, and I was driving on some rough roads.
Recommendations?
This antenna is paired with a MXT115. I have the same antenna paired with a KG-1000G on a roof mount on a pickup truck.
I added a spring base to the antenna on my Jeep and on my FJ later, which is taller. I haven’t bent or broken an antenna since I did this. YMMV.
I went to short Tram Browning NMO with a spring on my roof of pickup and it has work well so far. Struck something with it 2 days ago and it is okay.
Not 4X4 but I have a van and it’s about 1.9m tall and I use it for work so had uhf and vhf antennas on top. I had 5/8ths for VHF and I used a 5/8th over 1/4w for uhf. Occasionally I’d have to mark in multi story car parks and would regularly break these. I replaced these antennas with 1/4w vhf. So 1/4w for vhf is 3/4wave at uhf. These bang on the roof beams of the car parks and make nasty noises on height barriers but none have broken and the range is rarely an issue, they’re much more wide band, so ham bands, business and leisure bands are happy on the radios and I wish I’d dumped the clever antennas years ago. Uhf works really well on the vhf antenna, I suspect the lower radiation angle works for me. Best bit is the mounts allow forward and back adjustment but when you hit something hard, they just angle back.
Thanks Bob, and welcome to the forum.
Thanks go out to all who applied. I ended up picking up a new antenna locally that seems to be a little higher quality. 5 has 5 dB gain instead of 6, but seems to be getting the job done.
Hopefully this one will last a litlte longer. It does have a spring base.
On my rigs I tend to run 1/4 wave antennas on the roof unless it’s a soft top where that just isn’t practical (then I run a 1/2 wave antenna on the driver’s side fender) for VHF/UHF applications. I’ve found it’s just really hard to beat the functionality and simplicity of a 1/4 wave antenna in most real world mobile applications. They are cheap, typically $10 or less for a name brand Laird or Larsen, and depending on the terrain are more effective.
On my Cherokee I run a Larsen NMOQB with spring for VHF on the roof. It’s been there for 10 years now, drags going in and out of the garage, I hit it on things quite often, never have had a problem with it. On the same Cherokee I also run a Larsen NMO27B for CB on the fender. No spring, never have had a problem.
I’ve used 1/4 wave NGP (no ground plane required) antennas for GMRS.
Pretty sure NGP antennas would work better with a ground plane, but I have a Jeep with a fiberglass roof (often with a RTT mounted) and aluminum hood, so no option for a ground plane.
No. Antennas that are designed to not need a ground plane can’t just have one added, it wrecks the design. I sell lots of marine radios, and fibreglass boats are pretty common. They also need antennas that can be attached to horizontal rails, that kind of thing. Most ground plane independent designs use half wave dipoles, often sleeved dipoles where the ground going part of the design is a sleeve that goes back down the coax to allow the cable to escape at the bottom, not the centre. If you had a real ground plane, you’d need to drill a hole in it, and lower the antenna into the ground plane to the point where the centre core radiator is no longer sleeved. Halfway down, usually. Pointless, and totally impractical. Some designs have the grounded side of the antenna electrically shortened with a coil, and in these the top section might be the usual quarter wave, but the lower section maybe half or a third of the length. It has a good enough VSWR but I’m not sure it radiates or receives as well?
If you design an antenna, you use established rules. Slapping on extra radiators of different lengths to increase bandwidth, or changing the ground plane from a solid vehicle roof to a few horizontal elements changes how the antenna performs. Sometimes for the better, but mostly, these mods make them perform worse!
Hi @Yeoman
Have you seen the Overlander?
Than is a true beast of an antenna, I didn’t realise till I watched the video. That’s pretty impressive looking. ⅝ over ⅝ is a pretty tried and tested design too.
It depends on the antenna manufacturer. Most of the NGP NMO antennas from companies like PCTEL, Larsen and EM Wave can operate with or without ground plane. 0 dBd without groundplane, +2.5 dBd with ground plane typically (assuming it’s a straight 1/2 wave design).
Is that not just a manufacturer being creative with the spec? This is one example where the dBi calculation makes some sense - a comparison with a purely scientific standard. My understanding of doing this comparison has always been a point or two of a dB - as in a 1/2 wave dipole being just over 2dBi, and a groundplane 1/4 wave being just under 2dBi - mainly because of the capture area of the active elements being physically greater. With the base loaded 1/2 waves that claim better gain and no requirement for a ground plane I note so many ads seem to add “although they work better with a ground plane” - I always take this to denote the design that has acceptable electrical matching for a VSWR that doesn’t make the radio protest, but has less than ideal performance at actually working as a decent antenna.