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Reviews For: Diamond NR770HNMOB

Category: Antennas: VHF/UHF+ Omnidirectional: verticals, mobile, etc

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Review Summary For : Diamond NR770HNMOB
Reviews: 36MSRP: 59.99
Description:
2M/70CM Open Coil Dual Band Mobile Antenna
Product is in production
More Info: http://www.rfparts.com/diamond/index.html
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00363.4
N2EAC Rating: 2007-10-14
Garbage - Don't waste your money Time Owned: more than 12 months.
The other reviews say it all . . . water gets in over time . . . the loading coil corrodes . . . it shorts out . . . you fry your finals. Sure the antenna looks good and up to and until it shorts, it's great.

Diamond should put the following warning on the antenna package.

"WARNING - DO NOT EXPOSE TO WATER. IF EXPOSED TO WATER, THIS ANTENNA WILL CORRODE, SHORT OUT AND WRECK YOUR TRANSMIT FINALS."

This is the second one that shorted out for me in 4 years for my "Sunday" car that is garage kept and rarely taken out on days that it might rain.

This is not a cheap antenna. For $55.00, I expect more from Diamond. Two strikes here, you're out. No more Diamond products for this ham.

73, Ed, N2EAC
N2CLB Rating: 2007-05-27
WoW Time Owned: more than 12 months.
this is as good as thay get for a 1/2 wave 2M vert
N2GYI Rating: 2007-05-23
Junk Time Owned: 0 to 3 months.
Intermittent high SWR issue right out of the box. My simple 1/4 wave magmounts easily outperformed this antenna. Don't waste your money.
KT6K Rating: 2006-10-18
serious ground plane problem solved Time Owned: more than 12 months.
I had a serious ground plane problem on the Harley or the Corvette. A rubber ducky was better than anything else I had tried. When I was in Las Vegas visiting some friends, they jumped in on the conversation and suggested that the Diamond NR770H series worked 'real-good' without a good ground plane.

Now I get compliments on a 'full-quieting' signal both from the Corvette and the Harley, both sorely lacking in the ground-plane department.

I have only found one other person suggest the 'same' thing in the eHam review.
N2LJ Rating: 2006-03-01
Short life Time Owned: more than 12 months.
Thought it was just my antenna, but then stopped here and saw all the dismal reviews. Same thing. Worked fine, than stopped.

You know it's bad when an HT at 5 watts with a mag mount on the roof gets into a repeater better (from the same location) than a 50 watt mobile with a permanent antenna!
I used the Diamond 400-series mounts to put the antennas on the rear doors of my car:

http://homepage.mac.com/ljwest/PhotoAlbum17.html

I've got one each side now.

I had a Diamond M285 on the second mount, cut for 157 Mhz (Marine Band, I'm a USCG Auxiliary Radio Facility), and THAT worked better into repeaters than the buggered 770. Having the two mounts allowed me to eliminate the feedlines as an issue.

Will try the fix recommended below and see if that at least gives me a decent backup antenna. In the meantime, it's back to the 8-year-old Larsen NLA mag mount!

But I won't be recommending this antenna to anyone!

N2LJ
K0COM Rating: 2006-02-19
High SWR - Loading coil probelm Time Owned: more than 12 months.
I've had two, an NMO and PL259 mount. Both had failures in the loading coil that resulted in high SWR. While I bought a new Comet, I decided to see what was going on with the coil. Unscrew the antenna from the base coil, and remove all the solder in the center top of the coil assembly. The cover of the coil assembly can then be unscrewed from the mount using a couple of big plyers. You will find moisture has gotten into this assembly with much corrosion. Clean up the coil, replace the 6 pf cap, resolder everything, use rtv silicone to seal it up when you reassemble and you will have a good antenna again. I used a 5 pf 1000 volt cap and all worked out well.
W8MJE Rating: 2006-01-10
Unreliable Time Owned: 0 to 3 months.
Bought this to replace a monoband Comet. It worked okay at first- and then the SWR on 2M (but not 440) shot way up. I reattached it, tightened the set screws, and it was fine. Then SWR shot up again- and this time reattaching and checking screws had no effect. I'm planning to send it back and see what happens, but I'm also planning on buying a better antenna.
ZL2UFI Rating: 2005-08-04
Robust - seems OK Time Owned: 0 to 3 months.
I have owned this antenna for about two months, and use it around the city as it's physically lenght is just under a metre - see my review of the Comet SB15 Triband Mobile Antenna.

Being smaller in length that the Comet the vehicle easily passes under car ports, garages, and underground or car parking buildings without having to be removed or folded down.

I have the chrome version.

I live near the sea, so it appears to be resisting the salt air well, and shows at present no shows of rust or other signs of weathering.

It's performance is down on the Comet, but for the size it works well, plus it draws less attention than the Comet, which is almost twice the size.

When away from the city I place the Comet on the vehicle as the additional S points, 2-3 more, are much better.

Apart from that I am happy with it.
KL1PL Rating: 2005-08-03
Works Well Time Owned: 3 to 6 months.
Bought it used off EBay for cheap. Run it on the boat in Prince William Sound. Works flawlessly at 35-50 watts. Use it to work the IRLP Node in Whittier and it beats the 1/4 wave I was using hands down on VHF. Have not tried it UHF, will get to that soon enough just for grins!
N1UMJ Rating: 2005-06-10
Great antenna Time Owned: more than 12 months.
I've had this antenna mounted on the back of a Satern for 2 years now on a trunk lid mount and it works perfect, now have a new rav 4 and plan to put it on the roof rack of that next. I don't expect any problems since I haven't had any yet. It gets out very well, hits and hears repeaters all over the place, really impresses me what it can do some times, I think it heard better than my base antenna some times and gets out to pretty much anything it can hear.