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Reviews Categories | Antennas: VHF/UHF+ Omnidirectional: verticals, mobile, etc | Diamond D-130J discone Help


Reviews Summary for Diamond D-130J discone
Diamond D-130J discone Reviews: 39 Average rating: 4.7/5 MSRP: $79
Description: 25-1300 MHz Continuous Coverage Super wideband antenna
Product is in production.
More info: http://www.rfparts.com
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You can write your own review of the Diamond D-130J discone.

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W6CAW Rating: 5/5 Dec 2, 2015 13:09 Send this review to a friend
Works!  Time owned: more than 12 months
Using it for TX on 6M,2M, 220, and 440.
Make sure you tune for the 6M area you are using. Works as expected for a unity gain antenna. Been in the air in the high desert for over 5 years.
 
K5ACL Rating: 3/5 Dec 2, 2015 05:27 Send this review to a friend
Used in conjunction with SDRplay for SWL  Time owned: 3 to 6 months
I think I expected more from this antenna when I first purchased it. But this antenna is definitely a compromise. If I could have gone back and purchased something else I would have. This may be good for a scanner enthusiast, but wasn't what I was looking for. It has nominal gain compared to other antennas of its size, which is why I decided to part with it and switch to a j pole for VHF. I purchased it from DXengineering for $95. I had it mounted at my roof line with a clear line of sight over the entire city! I live on a big hill. The only thing I could seem to pickup was local repeaters with it. I tried feeding it with LMR400, made no difference (barely), and I also tried quad shield coax just to see how it would work, and same results. The antenna is very quirky and clunky to handle, and I feel that the rods are very thin material (very easily bent). Definitely not a bad price for the antenna, you may have better results depending on your location.
 
W6LBV Rating: 5/5 Sep 12, 2015 08:29 Send this review to a friend
Fine Antenna, But Watch Out for Six Meters  Time owned: more than 12 months
I have owned and used a Diamond D130J for about fifteen years. For all of its lifetime it has been mounted at the roof line of my house, exposed to the weather, fed with low loss 50 ohm coaxial cables (of various kinds), and used almost exclusively for VHF/UHF receive. It has served well for general receiving, and it continues to do so. I have had almost no mechanical problems with it. It is really all that one would need for general local monitoring purposes.

However, this is not to say that it is perfect. Recently I obtained an AIMuhf Vector Network Analyzer. In the process of doing routine frequency scans of all my antennas with the VNA, I also scanned the Diamond.

Prior to the work, I did not expect the results that I found by scanning. The antenna (more precisely my individual sample of the antenna) displayed a “split personality!” The scans showed that above 100 MHz and all across the band through the top frequency limit (of the VNA), the Diamond produced a very good, almost excellently flat impedance match and a remarkably low SWR. The broadband matching was about as good as I have seen with any other antenna.

However, from 25 MHz (the lowest operating frequency for the antenna) through about 100 MHz, I found exactly the opposite. In general the impedance match was poor, with huge oscillations in SWR over the frequency range. The antenna’s ability to receive below 100 MHz is delivered by the (optional) upper vertical radiator, which itself contains a loading coil. Remove this rod and the antenna’s receiving ability below 100 MHz is reduced, but the (now smaller) antenna continues to receive well above 100 MHz.

The fact that there is a loading coil in this radiator probably ensures that the antenna cannot be made “broadband” on this lower frequency segment. Its performance must necessarily “peak” at some point in the frequency spectrum. And it turns out, with closer inspection, that a particular good match point occurs directly at 50.0 MHz. The resonance bandwidth is not very wide, but it may be enough to allow some QSYing at the bottom end of the band. The manufacturer claims that the antenna can be “tuned” for this Amateur band, but does not supply directions for doing the tuning.

Thus a pair of cautions: First, these results apply only to my own antenna, which might not represent other D130J Diamond antennas. Second, by ignoring the <100 MHz impedance matching losses, the Diamond can probably be used successfully for receiving across its entire operating frequency range (25 - 1300 MHz). However, if one wants to use it for transmitting, especially on 6 meters (and 4 meters, in the UK and elsewhere), then care needs to be taken to ensure that successful impedance matching is present. Also, per the manufacturer’s data sheet (http://www.diamondantenna.net/d130j.html), the maximum rated transmitted RF power for 50 MHz SSB is 50 watts.
 
W9FR Rating: 5/5 Sep 9, 2015 13:19 Send this review to a friend
Good six meter antenna  Time owned: more than 12 months
I have had this antenna for about 20 years and primarily used it for scanning Airband and V/U bands. I decided to try it on six during the Es season with on,y 100 watts. I managed to work 110 grids, 30 states and 18 countries in 4 continents. This was my first exposure to six meters about 6 years ago. It peaked my interest in the magic band and since then I use a 4 element Arrow yagi complimented by the Discone for quick checks of band conditions due to it omni pattern. Considering that it is vertically polarized, I was surprised with its performance. While it can't compete with the yagi, I believe it serves a very useful purpose on six meters. As others have stated, it still looks new after all these years. It is located at 35 feet on the side of my tower. I would recommend this antenna for any one interested in the VHF and UHF bands.

 
KK9H Rating: 5/5 Sep 9, 2015 05:40 Send this review to a friend
Many years of service  Time owned: more than 12 months
I have had one of these antennas installed since 1993. I have the N-connector version mounted at 35 feet fed with about 20 feet of RG-9913. This antenna is used with a broadband scanner radio used primarily for listening to local police and fire channels, but I also use it to tune around the aircraft, marine, business and amateur radio bands. This is a superb wide frequency antenna. O'Hare airport is about 12 miles away and I can easily hear the planes on the ground as well as planes in flight up to 200 miles away. Eventhough the VHF-low band is pretty quiet now, there are still some things to be heard so the loaded vertical section does add that capability nicely. Our state police used to use 42 MHz channels and I was able to hear mobiles regularly up to 30 miles away. At the other end of the spectrum I have also used it to listen to 23 cm repeaters which it does quite well. With respect to durability, it has survived many powerful storms over its 20+ years of service and it still looks like new. This is an excellent discone antenna and I would definitely recommend it to others.
 
N4THC Rating: 5/5 Sep 7, 2015 15:50 Send this review to a friend
Covers so much  Time owned: more than 12 months
I've owned this antenna since 1990. It has been used mostly as a 2m/70cm antenna with good results. I replaced it with a gain dual band antenna with not much better results. I went back to using it for 2m/70cm. I feed it with RG-213 and have it at a height of 20'. I hit any repeater I need to and am able to talk as far as I need on simplex. Today I decided to try it on 6 meters (at least tuning it). Since it uses a vertical whip with a bottom loading coil, it's bandwidth is not great. It does not cover the whole 4mhz of the band, but only about 2mhz of it. I kept it tuned for the upper FM portion since this is vertically polarized anyhow. I don't plan on any different antenna for now. It has held up quite well with no corrosion.
 
VE9DAN Rating: 5/5 Jun 4, 2015 03:01 Send this review to a friend
Works Very Well  Time owned: 0 to 3 months
I just installed a brand new, shiny D-130J. Yes a wee bit tedious to put together as previous reviewer said, but not at all bad. The model number implies an SO-239 connection.
All components are stainless and I was afraid the small set screws would 'gall' and seize. For each threaded connection I applied Penetrox ... an electrical conductive paste.
I live beside salt water, so the paste may also help to prevent the ingress of salt into the assembly.
The antenna works very well on my AIS system (APRS for ships) and yields simplex signals from 80+ Kms away regularly. It is mounted about 16 feet above ground near sea level.
Due to my location, I have no real plans to use it for transmitting (I use a beam to get to the repeaters). I do like the omni-directional aspect of the antenna, and plan on tieing it into my scanner in due course, along with the addition of a pre-amp.
If your location and circumstances are similar to mine, then I would have no problem in recommending the unit.
VE9DAN
 
KB6DRN Rating: 5/5 Mar 10, 2015 09:49 Send this review to a friend
restricted Space Transmit Antenna  Time owned: 3 to 6 months
I'm using the D-130J Discone Antenna as an transmit/receive antenna for my four mobile FM radios mounted on my Ham Bench. The radios include 6 meters, 2 Meters, 1.25 Meters and 70 Centimeters. The radios are combined via 3 Diamond mobile duplexers/triplexers onto a single coaxial cable feeding the Discone Antenna.

The discone antenna is on a pipe which is just above the roof line of my house and works very well. The SWR remains between 1.25:1 and 1.50:1 on all four bands and accesses repeaters between 80 & 100 miles away - 90% of them worked at Full Quieting Levels. I was also impressed with the construction of the antenna which is far better than a Radio Shack discone I've previously used.

Had I put up 4 monoband antennas rather than the single "frequency multiplexed" discone system, I believe that my $400 dollar cost for all materials would have doubled and of course, my backyard would be full of antennas and peering, sneering neighbors. It's also interesting that I could add 900 MHz to the antenna system with the addition of another mobile duplexer as the discone provides low SWR from 50 MHz to 900+ MHz.

While I wouldn't recommend this antenna for VHF/UHF DX work, It's a perfect antenna setup for a restricted space environment and communicating with Ham Repeaters.
 
K6MTS Rating: 4/5 Jul 7, 2014 00:35 Send this review to a friend
Pretty good cover all antenna  Time owned: more than 12 months
Works great. My only issue is the design is a bit silly. The way it was designed (use and placement of tiny screws, washers, and set screws, along with their relationship to the radial position, makes it tedious to put together and take apart to move.

Also could easily have been designed to be more mechanically sound as far as how it mounts to mast.

5 for performance, 3 for user/installer friendliness, = 4.
 
K5AHH Rating: 4/5 Jun 6, 2012 17:58 Send this review to a friend
Good Antenna  Time owned: more than 12 months
--I owned one of these antennas for five years. It's just about comparable to a quarter wave. A 2 meter signal that was S7 on a quarter wave was an S6 on the discone. Virtually the same results on 70cM. When used on 6 meters, the SWR on my antenna was 1.7-2.5. Not great, but acceptable. My Cushcraft AR-6 works much better (as it should). On both 2 meters and 70cM, SWR ranged anywhere from 1.2:1 on up to an acceptable 1.9:1

--Easy to put together. I've read several places that the lower elements, or the "cone" are solid, but mine were hollow. This was not an issue, though, in my opinion. Some of the hex nuts had rusted that hold the "cone" elements after a few years.

--While this antenna, at least in my experience, doesn't seem to "hear" as well as a quarter or half wave antenna, I would recommended it to a scanner user. It works fairly good for RX from 44Mhz to 467Mhz, such as low band Highway Patrol (44Mhz in this area), 6 meter amateur band, 118-136Mhz aircraft, 2 meter and 70cM. No other frequencies were tried. It sure beats having individual antennas for all the bands this antenna covers! I ended up giving the antenna away to a friend and I put up a beam. I've been thinking of buying another and putting it up at work.
 
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