Diamond V-2000 triband vertical review - a replacement for an older Diamond X-50 dual bander

My old Diamond X-50

The new Diamond V-2000 in situ
The 6m inverted V is pointing
east to Europe

Diamond X-50

As mentioned in a previous post my dual band colinear had suddenly gone deaf. When taken down it was found to be a Diamond X-50. I had totally forgotten what make or manufacturer it was. It was still in excellent condition when it was brought down from its home for the last 15 years atop an 8 foot long pole.

I investigated it and found that the PL259 had a slight amount of corrosion despite it being wrapped in self amalgamating tape and in turn being inside the lower pipe of the antenna.

Diamond V-2000 triband vertical antenna

I received the new antenna and assembled it. This one now has two set screws holding the support pipe to the base of the antenna so Diamond have listened to the criticism on internet forums about the the previous 1 set screw fixing. Now it is really strong and gives you confidence.


The quoted specification (UK Spec) of the antenna is thus:

• Frequency: 50-52 MHz, 144-146 MHz, 430-440 MHz
• Gain: 2.15dBi(6m), 6.2dB(2m), 8.4dB(70cm)
• Impedance: 50 ohms nominal
• VSWR: Less than 1.5:1
• Power Rating: 150 watts
• Element Phasing: (6m) 1/2 wavelength (incl. counterpoise)
• (2m) Two 5/8 wavelength
• (70cm) Four 5/8 wavelength
• Radials: Three
• Grounding: DC Ground. Antenna element & radials connected to mounting pipe.
• Max. Wind Rating: 50m.second (112.5 m.p.h.)
• Mast Dia. Acceptance: 30mm to 52mm (1.2" to 2.4 ")
• Length:2,5m (8.3 ft).
• Weight: 1.2 kg (2.6 lbs).
• Connector: SO-239 female
• Req. Triplexer: MX-2000 
• Limited Warranty: One year against defects in material or workmanship.

Internals

I had a look at what was inside the top section of the antenna prior to fixing it to the lower section.

Top section out of its fibreglass cover

The top section comprises a few wound coils in a hard brass wire with soldered connectors here and there. There are also 5 foam spacers to hold the element away from the inside of the fibreglass tube. The lower section of the element has a brass socket with a set screw. The lower element pushes into the socket, the set screw tightened

Upper element to lower element coupling

Upper element and lower element joined together

The fibreglass sleeve is placed over the upper element. There is a rubber seal and a metal coupling screw that join the two halves together.

Rubber seal, ferrule and metal screw coupler

There is a black mark on the fibreglass sleeve that is intended to show how far inside the fibreglass sleeve goes into the lower section. This is so it has sufficient support when assembled.

Once the connectors are screwed together and nipped up with a pair of spanners (wrenches) there is a watertight seal created.

Couplers read to be nipped up

Cable.

I used the MESSI & PAOLONI ULTRAFLEX 7  cable and its accompanying PL259 connectors. They are not cheap but fit the cable perfectly. The also have a compression fitting for the outer conductor and a soldered connector for the inner conductor.

I wrapped the PL259 with some self amalgamating tape.

Ultraflex 7 PL259 wrapped with self amalgamating tape

Here are the instructions to connect the M&P PL259 to the Ultraflex 7 cable.

MESSI & PAOLONI ULTRAFLEX 7  connector assembly

Antenna Mounting

The antenna comes with its own brackets that enable fixing to a mast up to 2.4" diameter. My 6 foot long pole is around 2" diameter and fitted perfectly. The 10mm U bolts tightened onto the pole with no effort at all. The antenna cable then passes through the antenna mounting tube and is screwed onto the base of the antenna.

Cable passed through the mounting tube

PL259 screwed into the SO259 socket on the base of the aerial

Self amalgamating tape was then wrapped around the plug to seal it completely

The radials were fitted as shown and the longer adjustable 6m radial was mounted in the hole adjacent to the mounting fixing holes.
The cable was then tied to the pole for about 3 feet with black nylon cable ties. There is a 10" diameter loop in the coax just under the mounting point. Diamond recommend doing this as an isolation choke to prevent stray RF coming back down the screen of the coax and therefore back into the shack.

Tuning.

I tuned the aerial for minimum SWR on 6m while raised about 12 feet from the ground as per the instructions and got it down to 1.1:1 on the FM 6m calling frequency 51.510 MHz. The SWR cannot be tuned on 70cm or 2m but it measured 1.05:1 on both bands. The length of the radial protruding for information was 23" (584mm)

Erection

The antenna was put into place by JNB Aerials http://www.jnbaerials.co.uk/ and I have great praise for the guy who came. He took the old X-50 down and replaced it with the V-2000. He used a cat ladder to get onto the roof and took the time to tidy all the routing of the cable down the roof and wall. I had to supply the 9mm cable clips as the UltraFlex 7 is an unusual overall diameter. Fortunately I had more than enough. He also pushed the cable through my external antenna junction box, through my predrilled 25mm hole in the brickwork and on through into the shack. He also resealed it with silicone sealant. Al in all a great £54.00 including VAT spent. There was no way I could or even would go up onto the roof.

I shortened the antenna cable once in the shack and terminated it in another M&P Ultraflex 7 PL259 plug.

Results

The antenna is now on the chimney and the station can hear again! The Wouxun quad band rig has got even better than before and has the added benefit of 6m transmission.
According to my Avair AV-601 I am getting the following results. The older X50 is placed in comparison: (all figures are in watts)

The antenna is extremely well made from top quality materials and if the previous antenna is anything to go by should last years and years. Obviously I am very pleased with the power figures and 60 watts on high power on 6m might be optimistic but that's what the power meter reads. 50 on 2m and 30 on 70cm are also very good. The sensitivity of the receiver has gone up and stations that couldn't even break the squelch before are not coming in really well.
I think the combination of the higher gain antenna AND the better coax cable have worked together to give better results. The previous cable was U213 and servered me well for many years and if it hadn't been for the slight corrosion in the PL259 at the antenna end it would still be up there. I will use the good bits of that cable and the offcut from the UltraFlex 7 in future antenna projects.

All in all it was well worth the upgrade to the better antenna and although the 6m antenna is actually a directional inverted V pointing at the sky (I have it pointed east to Europe) rather than a true omni directional vertical I think I am all set now for the two VHF bands and 1 UHF band,

The V-2000 antenna is currently available from Martin Lynch (and many other suppliers) for £109.95 including VAT. The M&P UltraFlex 7 is also available from Martin Lynch at  £29.70 for 25 metres and each PL259 is £6.29 - more expensive than regular PL259 but in my opinion a far superior product.

73 de Terry G8YPH July 2015