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Reviews Categories | Antennas: HF Mobile & Accessories | Diamond CR-8900 Help

Reviews Summary for Diamond CR-8900
Reviews: 17 Average rating: 3.5/5 MSRP: $100
Description: Quad band mobile antenna - 10m, 6m, 2m and 70cms. 1.26m long, 60 watts max for SO239 mount.
Product is in production.
More info: http://
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M0COM Rating: 5/5 Nov 18, 2009 13:39 Send this review to a friend
not a bad antenna  Time owned: more than 12 months
Lets start with no mag mounts
this antenna needs a very good earth . I got mine from Japan on e-bay nice and cheap compared to some of the ripoff prices in the UK.
I put it together mounted it on a k400 mount on the boot and ran a separate earth to the mount
and guess what!
2m swr 1-1.2
70cms swr 1-1.4
6m swr 1-1.7
10m swr 1-1.1
I have worked all over Europe on 10m. I have worked state side on 10m. On 6m I have worked 8 European countries.
On 2 and 70 a good 20ish repeaters.
This is driving home from work not parked up on top of a hill.
This antenna will never be as good as a mono bander but close attention to where it is mounted
and a good earth. Please read the instructions that come with this antenna
and yours should work as per their specs. Total time spent tuning antenna was aprox 5 min
K7TUX Rating: 3/5 Jul 16, 2009 10:32 Send this review to a friend
great on 2m and 70cm  Time owned: 0 to 3 months
I have gotten nothing but rave reviews from other people concerning the range/sound of my antenna. On 70cm and 2m, I regularly hear that I sound the best that anyone has heard at my range. I regularly hit repeaters within 40 - 60 miles on 2m and 70 cm. I have done simplex on 2m up to 30 miles with little to no static. I am still working on testing the full range.

However, where this antenna fails, is on 6m and 10m. I have tuned it to the best that it can be tuned, and still have yet to hear a 10m contact. I can hear 6m ok, but have yet to make any contacts. Maybe when the band opens a bit more, that will change, but I just cannot seem to be able to hear/reach any of those two bands. NOTE: Grounding is super important to the 6m and 10m bands. Make sure the grounding is to the frame or to a good solid ground. I was not able to get any reception on 6m until i grounded the antenna.

I also have had an issue with the fold-over spring being weak. When I hit 60 - 70 mph, the antenna starts to fold over on its own due to wind drag. I have contacted Diamond antennas for support. I will update this when they get back with me. Hopefully, they can replace the spring, etc.

Would I recommend this antenna? I am not sure. I have only had it for 2 - 3 months. I will hold my final evaluation till after my antenna gets returned from Diamond.
KD8IZM Rating: 3/5 Aug 10, 2008 14:21 Send this review to a friend
Specs for you to decide  Time owned: 3 to 6 months
This can be a good antenna for you. You just need to decide how much performance drop you are willing to take, and what bands are important to you.

Mounting the antenna on my Subaru outback, very close to the center rear of the roof, about 15cm from the complete rear of car (including the back hatch) with a permanent drilled in NMO mount with a uhf adapter:

My best overall swr per bands (on average, middle of band numbers) are approximately; 1.4:1 on 2m and 70cm. An amazing almost completely 1:1 on 10m, I can't tell you exactly what it is, but it is closer to 1:1 than it is to 1.1:1 on my meter, and last, 2.2 on 6m.

The best I could do on each individual band was 1.2:1 on 2m and 70 cm, the 1:1 it is now on 10m, and 1.9 on 6m. These peak numbers however are at a larger expense to the other bands (except the 10m) Ex. You can get 1.9:1 on 6m, but then you have about a 1.9 or 2:1 on 2m and 70cm.

If you are not to much into 6m, this is a good antenna. Unfortunately for me, I would MUCH rather that 1:1 to be on 6m than a 10m ban I don't use. I have heard someone using 10m fm only once during a good sp-E. Yesterday was an great aurora opening on 6m, and even though I can year it just blowing up, I can't talk back. I would guess that part of that 25% of my signal lost at some ends of the 6m band would have something to do with that. If 6m is quite important to you also, you will likely want to use a separate 5/8 wave 2m antenna and a switch with this antenna for best performance. That way (at least for me) when I hear that 6m is opening up, I can flip over to the other antenna and get a 1.1:1 on 6m. Of course most people (including me) did not buy a quad-band antenna to have a second antenna on their vehicle, and, well, it is just a letdown. If you are not big on 6m though, the swr on 6m is acceptable and will not hurt your radio.

I did in the past have this on the mfj tri 5" mag mount with a uhf connector for those considering it. It worked great on 2m and 70cm, and for complete crap on 6m and 10m as one would expect. The swr's were not damaging, but were close. It was not something I would recommend if you will really use your radio on 6m and 10m.

This antenna is alright. I would have gave it a 4 if the 6m was not so weak. I would expect all areas of an antenna that are mounted in placement that the manufacturer suggested, and on a better mount than they suggest, would at last be less than 2:1 on all bands it covers.

This antenna is also quite comparable to the only other quad band antenna that I know of, and it is a bit cheaper.
VR2XMQ Rating: 2/5 Jul 24, 2007 22:48 Send this review to a friend
Not Good  Time owned: 0 to 3 months
Have tested the antenna on 29MHz FM, 51MHz FM, 144 and 430 MHz. Mine was from Diamond from Japan, so instructions were all in Japanese.

After giving it to a Japanese friend to translate, I tuned the 1OM FM as specified, installed the antenna and used an antenna analyzer to test it. Despite trying to tune the end stub for 10M FM the antenna would not resonate anywhere near the 10 FM portion that it is specified to. The only way to even get it near resonance is to use a antenna matcher.

The same poor performance was found with 6 meters and it did not resonate in the 51MHz portion as so specified. The best was a match at 50.200MHz 1ith 1.8:1, to lower the swr again a matcher is needed.

144 and 430Mhz were ok, but performance was not something to jump up anddown about.

If you want to use it for 29MHz and 51MHz FM, there is no chance without an antenna matcher.

Very poor and not up to expectations.

Steve, VR2XMQ
2E0KPX Rating: 2/5 Jul 13, 2007 23:20 Send this review to a friend
Diamond CR-8900  Time owned: 0 to 3 months
Like G4IJE I have my CR-8900 magmounted to the roof of my car and find the SWR out of range on 6m.
Works well on 2m (1.1/1.2) although I have no idea whats going on on 70cm as I dont have a SWR meter for that high frequency but then again this antenna is supposed to pre-tuned I read. So only 10m needs tuning ????? Hummmmmm I'm not so sure.

G4IJE Rating: 3/5 Jul 27, 2003 12:35 Send this review to a friend
SWR not good on 6 metres  Time owned: 0 to 3 months
Well I've had a tweak but the adjustment provided only affects 10 metres. I can get a good match around 29.600 MHz (about 1.2:1) but on 6 metres the SWR is still around 2:1 at 51.510 MHz. It doesn't get any better on other frequencies in the band (50-52 MHz). The antenna presents a good SWR on 70 cms (best around 433-434 MHz), so three out of the four bands are as they should be. Shame about 6 metres; not sure what do about it.
G4IJE Rating: 4/5 Jul 25, 2003 17:09 Send this review to a friend
Early impressions are good  Time owned: 0 to 3 months
This quad-band mobile from Diamond is apparently designed for use with the Yaesu FT-8900R - hence the model number. I have just compared it with the Diamond DP-TRY2E and it is noticeably better on 2 metres (1-2 dB at a guess) and maybe just a fraction better on 6 metres. This was a suprise as I had assumed that to cover 4 bands the performance on each would be severely compromised. The SWR around 145.500 MHz (the European FM part of the band) is good but it's not so good on 6 metres. At 51.510 MHz (UK FM calling channel) it is about 2:1. However, if I can decode the Japanese instructions that come with the antenna I may be able to improve that a bit, as some adjustment is provided. A 10 metre FM test (at 29.600 MHz) was inconclusive as I don't have an SWR meter for such a low frequency! I haven't had a chance to check out 70 cms performance yet. All my tests were carried out with the antenna plugged into a heavy-duty 7" diameter magmount on the roof of my car.

My initial impressions are that this antenna may well be an ideal companion for the FT-8900R, as long as the SWR on 6 metres can be trimmed down to a reasonable level.
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