Monday, November 30, 2009

Fake Diamond

A few weeks ago I wrote about the Diamond SRH805S stubby helical antenna I bought on eBay to use with my VX-8E. Its performance turned out to be much worse than expected and the antenna was not even resonant in the 2m band according to my antenna analyzer. Having looked at it a bit more closely I now believe the antenna I bought is not a real Diamond SRH805S at all.

The pictures above show, from left to right, the antenna I bought, an unbranded "short dual band SMA antenna" advertised by an eBay seller from Hong Kong, and a picture of a genuine Diamond SRH805S taken by an owner. You can see that the fake antenna and the unbranded antenna look identical apart from the "Diamond" labelling on the fake. There is a wide knurled brass band on the fake and the unbranded antennas, where the real Diamond has just a narrow smooth band. The fake and the unbranded antennas both have a double groove molded into the case, the real Diamond doesn't. The picture of the unbranded antenna gives its height as 52mm, matching exactly the one I have, while another picture I found of the Diamond SRH805S shows the height to be only 45mm.

The word "Diamond" on the fake antenna is not in the same font as on the real antenna, which uses a bolder font matching that used in Diamond company advertising and on the packaging. The labelling on the real antenna is blue while the fake is white. To be fair, I have found an image on a Canadian radio dealer's site where the labelling is white. It is also written top to bottom rather than bottom to top and has an aircraft logo on it. This may be a picture of an older version of the antenna.

The fake antenna came in a genuine-looking plastic case with a yellow back and a clear front. The forgers appear to have reproduced the lettering exactly. But on the genuine antenna cases the model number SRH805S is written in red. The genuine Diamond antenna comes with a rubber washer to seal between the antenna and the radio body if there is a gap. It also includes a printed sheet giving the specification of the product - the fake didn't.

One clue to the fact the antenna I bought was a fake is the price. I paid £6.99 including postage from Hong Kong for this antenna, which is about the same as the unbranded SMA antenna. Hams in the Far East have often told me prices there are a lot less than they are here so I was not as suspicious as perhaps I should have been.

Radioworld in the UK advertises the Diamond SRH805S for £25.96, while some Chinese and Hong Kong eBay sellers have what appear to be the genuine item (but could just be a better fake) for around £20 including postage. A Polish dealer (allegro.pl) is advertising what from the picture looks exactly like the antenna I bought for the zloty equivalent of about £14. A UK dealer (www.dvdongle.co.uk) is advertising a Diamond SRH805S for £13.99 but no picture is shown. In view of what I have discovered I would be interested to see what it looked like.

It might come as a bit of a surprise to many people that there are fake ham radio products on sale. I wonder how often these fake products are being passed off as the real thing for the full price?

What I want to do now is figure out how to get inside this antenna, preferably without resorting to use of a hacksaw, and see if I can tweak it down on to the 2m band and make something useful out of it.
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