Diamond 'mini-discone' D-220?

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oceans777

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Kinda silly replying to my own question but I saw one of these today in HRO and it looks kind of...cheesy. The horizontal disc elements are TINY.
And my girlfriend helpfully announced it was by far, the "cutest" antenna in the place.

Despite her glowing technical endorsement, I can't see paying the same price for it ($99 at HRO) as the D-130J or N and have some doubts about it surviving long on a vehicle.

Finally I'd like to thank me for replying and say I've really enjoyed this highly informative thread...
 
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traumacop

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D-220

I have been using one off and on since I picked it up at the Dayton Hamfest. It performs well. I have not been impressed with any antennas performance at 800 Mhz since most mobile antennas do no better than the 800 MHz antenna from RS right on top of the radio inside the vehicle.
The D-220 does slightly better. It is constructed very well, personally tested it to 90 MPH without any problems.
I placed it on a diamond magnet/suction cup mount and put it on the table and it performed as well as the Seeker 800 and the RS 800.
To fit into tight spots if your not using VHF or UHF, you can easily remove the top vertical loaded element.
If you’re looking for a good discone for 800 MHz, this definitely is a good antenna.
 

kb2vxa

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Hi guys,

Now WHY would anyone use a discone on a mobile when it's performance is equal to the standard groundplane (whip and car top) we've been using since the first shortwave set was put in a car? Oh well, to quote "Yogi", it's deja Barnum all over again.

OE7, your girfriend has good taste in antennas and I'll bet she's even cuter.

Well D, of course it's a "good" discone on 800MHz, it's ONLY a tad more than 100MHz away from resonance. Plug an 800MHz cell phone antenna into the scanner and notice the difference a great antenna will do. Cummon, a KB callsign has been around long enough to know what gain is. As for that discone mobile, see ya on Hamsexy! (;->)

IMO it looks like a fair "base station" antenna being compact and fairly unobtrusive as opposed to those that put the fear of the radio god in the neighbors. I have modified a few commercial high gain mobile antennas this way and they gave excellent performance without attracting the attention of the villagers, thereby avoiding the legendary torchlight parade.
 

traumacop

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Diamond D220 Discone Antenna

Warren

You obviously have nothing to offer on the antenna. To learn a little, click on the link and read some technical specifications. It shows gain in the UHF segment. So if the user is a ham, GMRS or other licensed user of the UHF segment, they would have a decent transmit antenna with "gain" on UHF as well as a broad receive antenna.

Notice I said "it performs well" and then elaborated on the 800 MHz performance. I also mentioned its construction because he questions its looks and ability to hold up "if" used on a vehicle.

If he wanted a cheap single band 800 MHz antenna, the cell phone comment may be an option. I haven't found them to be great performers and would recommend a higher grade antenna.

I could go on for days with a bunch of hot air and BS about my mediocre theories, what I have done in my years as a ham and how I'm ate up with my own importance. I was trying to help him with an answer to his question about a specific product.

BTW, I doubt your expertise exceeds that of the engineers at RF Parts.
 

HabboX

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QST magazine had a review of this antenna (or was it CQ magazine) and it seemed that this had the characteristics of a ground-plane antenna, not a discone.
 

Al42

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traumacop said:
You obviously have nothing to offer on the antenna. To learn a little, click on the link and read some technical specifications.
Link? There's no radiation pattern or gain info for the 220 that I could find.
It shows gain in the UHF segment.
Gain over? An isotropic? Their advertising budget?

The antenna is clearly a 2/440 (maybe 220?) vertical radiator with a very small ground plane. Probably radiates about as well as any 2/440 mobile antenna for half the price. Diamond makes some good antennas, but they also make some hype.
 

traumacop

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Al42 said:
Link? There's no radiation pattern or gain info for the 220 that I could find.Gain over? An isotropic? Their advertising budget?

The antenna is clearly a 2/440 (maybe 220?) vertical radiator with a very small ground plane. Probably radiates about as well as any 2/440 mobile antenna for half the price. Diamond makes some good antennas, but they also make some hype.

The link is at the top of the thread but here it is again

http://www.rfparts.com/diamond/d220.html

5.5 dBi (isotropic radiator). That calculates out to 3.35 dBd (dipole reference) since
dbi - 2.15 = dBd.

Try tuning your mobile 2/440 antenna on 900 MHz or just slightly out of the 2/440 segment and check your stand and wave ratio.
wave.gif
 

oceans777

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Thanks for the info - now I'll have to go get one..

Also good to know which base you use - I was also leaning towards the suction\mag base for home use and this helps a lot.

Thanks!
 

kb2vxa

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Darren,

Sir, your ignorance is showing. First of all my focus was on 800MHz, not the Amateur bands it's resonant on AND I'm not about giving a course in wavelength vs. gain as you should already know. Then Al backed me up and you insulted his intellegence as well, looks to me you need some elmering but are just as likely to reject it since two whom have disagreed with you have proven you to be just what you called me in so many words, a self important know-it-all. Now here's the clincher.

"Try tuning your mobile 2/440 antenna on 900 MHz or just slightly out of the 2/440 segment and check your stand and wave ratio."

It's pretty obvious you never even tried to tune a Diamond dual bander! If you had you'd know that it cannot be optimised on 2M without upsetting 70cM and vice-versa, if this poor sucker even attempts to tune it for 800MHz he'll louse it up so bad it'll never work again. "Stand and wave ratio"? Really, and I thought CBers were funny.

Flame off.

OE7,

Likely it's a good antenna electrically so if that's what you want go ahead and get one. What I don't understand is why you'd want a suction or mag mount for home use when it's made to be mounted atop a mast. It fits perfectly well with what I wrote about modifying a mobile gain antenna for home use (by adding a mounting flange with radials) and this thing looks to be a discone with a 2M/70cM mobile dual bander on top. I'll bet it's the baby brother to thier extended frequency discone with the 6M whip on top only it has one of the famous Diamond dual banders instead. I'll bet you could match that antenna up in the catalog. Bottom line guy is don't monkey with it, likely it'll receive well enough over the stated range and from my experience with the Diamond mobile in question it'll be an excellent performer on the ham bands with exceptional receive capabilities on the adjacent bands. I think Diamond came up with a good one but I wouldn't put that silly looking contraption on my car. (;->)
 
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oceans777

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Warren -

I went ahead and picked one up today but have not had a chance to set it up yet.

Unfortunately I'm in a corporate apt in CA about half of the time and already have
several of the MFJ tripods with masts crammed onto the top-floor balcony so the suction cup/mag mount makes a good alternative 'base' for the D220 - plus I need a new mag mount for the truck. I was tempted to skip it and save $40 in the store but no room on any masts left.

It is definitely more solid than it looked and seems pretty stout - will report my results with it after trying it for a bit.

Thanks!
 

kb2vxa

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Hi again,

You can save the suction cups and magnets for the vehicle or you can play Spider Man but you don't need them on the balcony. Did you think we put antennas only on top of the tower and let the rest of that vertical real estate go to waste? Uh uh, not having a tower or BMF antennas I came up with a nifty alternative, back to back wall brackets fastened together with stainless steel hardware. Using short bits of mast on the side mounted antennas I stuck them to existing masts, tripod legs, wherever I could squeeze in more antennas. You could probably consolodate your crops on that antenna farm while you're at it, then there's also "getting your ducks in a row" along the railing but you probably have that electronic fence up already, just add to it.

Before you're done you'll have that old biddy across the way with the binoculars wondering what's going on over there, just wear a black suit and cheap shades for that finishing touch. Remember Mrs. Kravitz? I'm sure we'd all like to hear how it all worked out, especially if she's wearing a tin foil hat and the police have locked her number out of the 911 system. (;->)
 

oneirish

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Anyone have any recent experience. considering purchase to use as a roof top antenna as I have limited space.

BS396,

I know this may come too late to be any use but I never really used my D220 because we bought a house not long after I got it and I put up a full-sized discone.

Anyway I put the D220 up on the roof for the past week to see how it did, specifically during the numerous wildfires active close by here in CA.

The bottom line - it's not going to get you the range or clear coverage of a larger discone obviously but it does decent job. It was poor on LAFD freqs in the 800 MHz range. I know others have said they had good 800 MHz but mine heard very few transmissions and in some cases the telescoping whip that comes with the scanner did better. Also was not stellar on the lower 150 MHz freqs of LA County fire but still picked up paging (strong) signals in the 152 MHz range. A PAR 152 filter installed did not improve 150 range performance.

It did well in the VHF aircraft range - picking up some distant ATIS that only the large discone hears.

It was better on the 400 MHz LAPD APCO-25 freqs than the D130-NJ discone, because it picked up less intermod and passed only legible signals to the scanners where the large discone picks up all the rubbish around and causes the Uniden BCD996T to overload quickly or stall on every other channel. Note the GRE PSR-600 has FAR less problem with intermod and overloading than the Uniden and still amazes me that it can pull in weak signals the Uniden never hears.

The D220 was fed into a Stridsberg VHF four-port active multi-coupler, tested with and without PAR VHF filters for 162 MHz ad 152 MHz. Running a BCD-996T, 898T, GRE PSR600 and AOR-AR500A+3. I also ran it connected directly to the Uniden and GRE separately for APCO-25.
Cable used was LMR-400, 50 feet. Bear in mind I am near Los Angeles which is an RF hell and very noisy.


I think you'd do ok with it - it's very sturdy and well built but still over-priced I feel. Definitely it needs to be outside on a roof or where it gets clear coverage.
Note that the current tech sheet on it now says not to use it with a magnet mount. I tried it with and without and saw no difference.

I might look at the small Icom or AOR - not sure which has the 2 foot discone, and ask about it before buying the D220. I know they cost more - I have no experience with either.
 
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Turbo68

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I use 2 Icom-AH7000 discone and i tested it againt the Diamond-D150/Comet-DS3000 and the antennas are 8 metres high and they dont even come close on performance compare to the Icom and using 20 metres of Belden-9913 low loss cable.

Regards Lino.

ALINCO-DJX2000
AOR-3000/AOR-3000A/AOR-8200MK3
ETON-E5 HF PORTABLE
GRE-PSR500
ICOM-R3/ICOM-R5/ICOM-R20/ICOM-PCR1000/ICOM-PCR1500/ICOM-PCR2500/ICOM-R9000/ICOM-R9500
JRC NRD-545
RADIO SHACK-PRO97
REALISTIC-PRO2035
UNIDEN-245/UNIDEN-396/UNIDEN-780/UNIDEN-996
YAESU-VX7R/YAESU-FT8800R/YAESU-VR500/YAESU-VR5000
 
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oneirish

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Doesn't surprise me. Diamond is kind of hit and miss it seems, some great antennas and some awful ones.
I still think my old Radio Shack discone outperformed the Diamonds.
Anyway I am switching to directional yagis and antennas with rotators soon. The discones just pick up too much garbage where I live.


I use 2 Icom-AH7000 discone and i tested it againt the Diamond-D150/Comet-DS3000 and they all the antennas are 8 metres high and they dont even come close on performance compare to the Icom and using 20 metres of Belden-9913 low loss cable.

Regards Lino.

ALINCO-DJX2000
AOR-3000/AOR-3000A/AOR-8200MK3
ETON-E5 HF PORTABLE
GRE-PSR500
ICOM-R3/ICOM-R5/ICOM-R20/ICOM-PCR1000/ICOM-PCR1500/ICOM-PCR2500/ICOM-R9000/ICOM-R9500
JRC NRD-545
RADIO SHACK-PRO97
REALISTIC-PRO2035
UNIDEN-245/UNIDEN-396/UNIDEN-780/UNIDEN-996
YAESU-VX7R/YAESU-FT8800R/YAESU-VR500/YAESU-VR5000
 

zz0468

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I wouldn't put one on my vehicle, being as I take my RF kinda seriously. I'm quite content with quarter wave spikes on the roof for VHF and above. I do know a ham with one of these things on the roof of HIS vehicle, and it looks anything but "cute". Every time I see it, I'm bombarded with several thoughts, always in the same order: kluge, Rube Goldberg, lampshade. Then I close my eyes and wince, and then I see the leg-lamp from the movie "A Christmas Story". I have no clue how well it really works. But they look hideous on the roof of a pickup truck. The specs are ho-hum.

As to the comments about the engineers at RF Parts, I'm not impressed. They let this slip past the guys in marketing:

[SIZE=-2]Element Phasing:[/SIZE] [SIZE=-2]Wideband Discone[/SIZE]
 

oneirish

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D220

Maybe he won the D220 in a 'contest'. It was a prize, much like the glorious lampshade...

It does look like a strange lamp somebody left on the truck roof that was hit by lightning shortly after. I can't imagine anyone seriously putting this on a vehicle. I'd give them a wide berth.
Could you imagine it on any emergency services vehicle for any reason?
 
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