6m mobile antenna

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What would be a good 6m antenna for the car? It needs to be either mag mount or lip mount for the trunk.
 

merlin

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My mobile 6 meter antenna was Antenna Specialist ASPA452. On a trunk lip mount that folded into the trunk.
It would outperform the 7' steel whip.
I could swap it directly with an M-125 tuned for 10 meters or the 2 meter version.
The antenna:
The mount was something like this: (Could be fixed to the hood lip also)
 

mrweather

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A Larsen NMO50 works very well as a monoband antenna on 6m. But, you're get more bang for your buck with an NMO150 since it does both 2m and 6m.
 

VE7_Rover

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I was speaking with NewTronics (Hustler Antennas) and was told the MO-1 and MO-2 masts are designed to be resonant on 6M.
I haven't tried it yet, but with an RM-10 resonator, one should have a dual band 6M/10M antenna. Ideal for those of us with radios that have 6M on the HF connector! Let me know your results.
 

mrweather

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The NMO150 may not be designed for 6m but it happens to work there. Electrically it's a base-loaded 1/4 wave, same as the NMO50.

The NMO150 was only offered as a suggestion because it gives you the benefit of it working on two bands.
 

prcguy

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The advantage is you will have a 6m and a 2m antenna in one antenna. The whip length will partially determine how well a dedicated Larsen VHF low antenna cut for 6m will perform against a 2m 5/8 used on 6m. I just dug out a 6m specific Larson and a 2m 5/8 Larsen and the 2m whip is about 4" longer than the 6m and that could give it a small advantage.

Is there an advantage to using the Larsen NMO-50 over the NMO-150 for 6m?
 

Cognomen

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This is great timing, because I was thinking of picking up a 6m antenna shortly, but I already have an NMO-150 not being used. :)
I'll dig it out, mount it, and will sweep it with a SiteHawk.

I actually don't need a 6m/2m antenna in one antenna; I use an NMO-WBQ140 for 2m.
 

jaspence

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6M is a strange band. If you haven't had experience with it, it can be frustrating. Having the 2M choice is a good idea, as it can be useless unless you are using it with a repeater.
 

krokus

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If you get the Larsen 5/8 2m NMO antenna it will work about the same as the antenna posted above as a resonant 1/4 wave with a good match and its also a 5/8 wave gain antenna for 2m.
Sounds interesting. Does this antenna work reasonably well on 70cm?
 

mrweather

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And I think the fact that the NMO150 happens to work on 6m is because the coil (VHF matching section) isn't DC grounded. I've come across other VHF 5/8 wave antennas where this isn't the case.
 

prcguy

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The old A/S 5/8 wave with the grey PVC pipe looking coil was a tapped coil and DC grounded. The later black cone shaped A/S VHF 5/8 and Larsen and Maxrad and most others are not DC grounded. I've also used a newer A/S and Maxrad VHF 5/8 on 6m.

And I think the fact that the NMO150 happens to work on 6m is because the coil (VHF matching section) isn't DC grounded. I've come across other VHF 5/8 wave antennas where this isn't the case.
 

merlin

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2 meter and 70 CM are fine with VHF antennas because the are near a perfect 3:1 frequency.
6 meter doesn't multiply evenly so you get bad performance on 6 with any 2 meter antenna.
Likewise, an antenna tuned for 6 works poor on 2 and 70cm.
seeing is believing looking at a VNA.
I will put up screenshots when I get my puter talking to the VNA again.
 

mmckenna

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2 meter and 70 CM are fine with VHF antennas because the are near a perfect 3:1 frequency.
6 meter doesn't multiply evenly so you get bad performance on 6 with any 2 meter antenna.
Likewise, an antenna tuned for 6 works poor on 2 and 70cm.
seeing is believing looking at a VNA.
I will put up screenshots when I get my puter talking to the VNA again.

I believe you are thinking of 1/4 wave antennas for VHF being 3/4 wave on UHF. That works well.

What they are talking about above is the non-DC grounded coil VHF 5/8th's wave VHF antennas being 1/4 wavelength base loaded on 6 meters.
1/4 wavelength on 6 meters is about 56-57 inches.
5/8 wavelength on 2 meters is about 49 inches, plus the length of the impedance matching coil in the base.
 
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