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Reviews Categories | Antennas: VHF/UHF+ Omnidirectional: verticals, mobile, etc | Diamond X-300A Help

Reviews Summary for Diamond X-300A
Diamond X-300A Reviews: 22 Average rating: 4.5/5 MSRP: $$139 HRO
Description: X300A Dualband Base/Repeater Antenna

Band: 2m/70cm

Max Power Rating: 200
Wind Rating: 112 MPH (no ice)
Height (feet): 10
Connector: UHF
Element Phasing: 2-5/8, 5-5/8
Product is in production.
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W4HWD Rating: 5/5 May 27, 2012 18:08 Send this review to a friend
Great antenna!  Time owned: 0 to 3 months
After reading some of the reviews, I'm wondering why it was so difficult for some to assemble this antenna. I believe some people couldn't find their own rear-ends with both hands! It took me about 6 minutes to put it together, and another 20 or so to climb on the roof, attach the LMR-400 and clamp it to the top of my 35' mast.

I hadn't been on 2 or 440 for a while and was very impressed with performance that exceeded my expectations. Using this antenna 35' AGL (about 15' above the roof) I was able to work, with a 5W Alinco HT thru 100' of LMR-400, 2M repeaters in the following locations: Abbeville, SC (85 miles away); Elberton, GA (91 miles away); Denver, NC (88 miles away); Marion, NC (43 miles away). All the local machines and machines closer but not necessarily local were all full scale. On 440, there aren't as many repeaters but the furthest one I was able to talk on was in Abbeville, SC (85 miles away). Now granted these are repeaters with high antennas, but the distances are still impressive for an antenna that is still way lower than the trees that surround it on three sides! And with 5W from an HT, I can't wait to see what it does when my new Kenwood V71A shows up later this week!

Only thing I noticed was the SWR is not quite as low or flat as advertised...the SWR on my antenna is 2:1 at the ends of the 2M band and only about 1.7:1 through the middle. That's a non-issue for me because dummy loads are 1:1, and I don't think the SWR really matters, as evidenced by what this antenna is doing on the air! We'll see how it holds up for the long run, I expect no trouble as it's built solid and in no way resembles a poor quality antenna.
W2ZOU Rating: 5/5 Dec 12, 2011 13:38 Send this review to a friend
Outstanding  Time owned: 0 to 3 months
Build quality is superb, excellent performer. I upgraded from a J-Pole, HUGE difference.
KF5LQI Rating: 5/5 Sep 2, 2011 18:26 Send this review to a friend
So far so good  Time owned: 0 to 3 months
Not sure what issues A1oc had. Yes the element for the upper portion was up inside the fiberglass shell. Looked up inside and then saw it was surrouned by a foam insert. A sharp rap on the table and out it popped. Bolted together with no problem from the radials (I did use a little red thread locker) Attached the base to a 10ft section of a 4inch fiberglass "C" channel and painted it camoflage. Used LMR600 cable to run it and hired a tree company to install it at the top of an 80ft pine tree in my yard. Tip of the antenna clears 90ft and I have worked simplex 20 miles and 32 miles thusfar using a 746PRO on 100watts.

I can't speak to the longevity, yet, but so far my expectations have been exceeded. For the money, I would buy again anyday.
AI0C Rating: 3/5 Jan 29, 2011 18:31 Send this review to a friend
A good antenna, but a few product issues  Time owned: 0 to 3 months
After reading the reviews here on I decided the X-300A was the antenna for me. As an antenna it works fine, but getting it up and operational was another matter.

Step 1 has you connecting the lower and upper elements. While the lower element was sticking out of its outershell, there was nothing sticking out of the other outershell.

It's a bit hard to see anything down that long dark tube of outershell, but I finally spotted the element. It took a bit of work to convince the element to make an appearance so that I could connect the two elements together. It would be helpful if the assembly instructions made note of this.

When I got to Step 5 where you attach the radial elements I ran into another problem. I couldn't get any of them to screw in! An examination with a jeweler's loupe of the three threaded holes in the base revealed them to have plated threads! The plating was apparently heavy enough to gum up the threads to the point that I couldn't get the radials to thread into the holes.

A trip to a nearby hardware store to purchase a 5 x 0.8 mm plug tap for $5 so I could chase the threads solved that problem. You wouldn't believe how much plating came out of those holes!

Step 7 was the funniest of them all. It said, "Attach assembled antenna on mast by whole balance into account." That's not a typo. At least not on my part.

I contacted RF Parts Co. (the distributor of Diamond Antennas in the US) and explained my problems with the X-300A. Their response? Silence.

In the end the X-300A is a good antenna but this experience will make me think twice about purchasing a Diamond Anteanna in the future or purchasing from RF Parts Co.
KE5NYS Rating: 5/5 Sep 26, 2010 09:07 Send this review to a friend
GOOD QUALITY AND RANGE...  Time owned: 0 to 3 months
I upgraded from the Diamond X30A to a X300A to obtain increased 2m/440 operation range, and was
very pleased with the results. I'm in the East Texas area, blanketed with many tall pine trees,
with the unit mounted on a short pole on my one story home roof peak. I'm soundly picking up repeaters 50 miles away, which is what I was seeking to accomplish. In my opinion, the Diamond brand is definitely a high quality product with good tech service if needed, and decent pricing
as well.
N2XPM Rating: 5/5 Nov 24, 2009 08:06 Send this review to a friend
EXTREMELY HAPPY  Time owned: 0 to 3 months
I bought this antenna based on the reviews from other users. The antenna is being used for my repeater and is replacing a Comet GP-3 that failed after 3 years of service. The antenna was put together rather quickly. It has more gain compared to the GP-3 and so far so good with the performance. I purchased it from R and L and delivery was quick, KUDOS!
N7TDC Rating: 5/5 Aug 25, 2009 20:25 Send this review to a friend
Superb Antenna  Time owned: more than 12 months
I've been using the X-300A for my RV base station and it's a superb antenna. I've placed it atop a 25' mast and I can RX/TX throughout the area with no limitations. I live in a very windy area in SE ID and this antenna endures gusty wind storm after wind storm without failing, while nearby towers and antennas are blown over and out of operation. I've been so impressed with the X-300A that I purchased two more Diamond verticals, the X-200A for field ops and a X-510HDM for home QTH base station operations. Thank you Diamond for the quality, durability and buy-it-now price of this line of antennas. This antenna is one of the top recommendations I give to other hams, and the antenna recommended to me by a veteran ham last year. You won't go wrong with this superb antenna!
W7KFO Rating: 5/5 Jul 19, 2009 17:17 Send this review to a friend
Flawless  Time owned: more than 12 months
I've had this antenna up for two years in relentless sunshine and high winds. It works perfectly, and VSWR is as advertised - below 1.5 to 1 across entire 2 meter band. I do a lot of simplex work and this antenna consistently outperforms the knock-offs my neighbors use.
KI6JLX Rating: 5/5 Feb 28, 2009 23:28 Send this review to a friend
No mounting problems here  Time owned: 0 to 3 months
I'm not sure why N0YK had such difficulty getting his antenna straight. I just mounted my X-300NA today and found it easy to twist the mast brackets to get a good vertical alignment. I *did* mount the brackets so that one bracket's lock screw was on the left and the lock screw of the other bracket was on the right. I don't know if that helps or not, but it certainly didn't hurt anything.

The antenna is nicely constructed and comes with all the parts you need to mount it on a typical antenna mast (or larger pole). The instructions' English is a little off in some places, but not enough that you can't figure out what you need to do to assemble the antenna correctly--especially with the good drawings that accompany each step. You'll need 8mm and 10mm open-ended (or ratcheting) wrenches and a Phillips screwdriver to assemble and mount it.

I'll update the review after I finish my inside wiring and get a few weeks' use out of it.
VE4EAR Rating: 5/5 Jun 26, 2008 14:41 Send this review to a friend
Great Antenna  Time owned: more than 12 months
I have the X-300NA, the N connector version. It has been mounted opn a 15ft mast on my roof for the last 2 years. Ity has survived the cold Manitoba winters, the strong 90 mph winds, ice storms and still works well.

VSWR under 1.5 across the entire 2m Band. UHF rises a bit higher as you work in the 430-435 MHz band band very low in the FM portion of the band.

I have seen no degradation in VSWR or performance over the past 2 years.

No tuning or adjustments are required. Open the box, assemble, install and enjoy.

Performance is what I would expect from this type of design. noticeable improvement over the 15 year old ringo ranger it replaced. Without using a spectrum analyzer, I would estimate about 1/2 to 1 S unit improvement on receive. This is what I would expect.

Mechanically solid, meets performance expectations. A little more expensive than some of the knock offs and clones, but it delivers and seems like it is built to last.

I wouldn't hesitate to buy one again.
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