I just purchased one of these on that auction site. Got a really great deal, which is why I did. After using it for a couple of days, I thought I'd put up this mini review.
First, I'm not going to talk about the legality of this transmitter. It has a Part 15 & Industry Canada certification sticker, and that's good enough for me (and it should be for the FCC and IC). I'm using it exactly as certified, with the supplied antenna, as would most purchasers without a multi thousand dollar field strength meter.
In any event, the range I get to a good car radio is comparable to other Part 15 certified transmitters I own and have owned - several hundred meters.
I have to say that the sound quality isn't as good as other transmitters (admittedly this is subjective). It doesn't sound nearly as rich as, say, the Decade MS-100 or the Landmark 350, with the same audio processing. It's closer to inexpensive car transmitters. That's not to say that it's bad, and to some extent, that would depend on your source material.
You can set the pre-emphasis, so that's good, and you can set it to transmit in mono (which I do), as well as stereo. You can also vary the line input level if you can't do that on your input source.
One interesting fact emerged. It doesn't pass the higher frequencies required for RDS/RBDS - at least, I didn't see anything on my car receiver. I've had no issues with various Decades that I've used in that regard.
You can power the transmitter in a variety of ways. Using a microSD cable generated some noise. The signal was quieter with batteries (it takes 3 'A' cells).
This transmitter would be great for car use, where the diminished sound quality wouldn't be as noticeable and the increased field strength over your typical car transmitter would punch through static. It might also serve as an inexpensive Part 15 FM transmitter if you can get it for a good price (I got it under $50 Canadian in new, open box condition). I couldn't justify paying full price ($150 Canadian or so plus shipping) for a new one and quite frankly, don't think it's worth it when you can sometimes find Decades for that (I actually got my latest Decade MS-100 in new condition for about $100 Canadian on that same auction site).
I forgot to mention. One of the tests I still need to do is to measure performance on different parts of the FM band. The antenna for the WHT V3 is just a short piece of wire encased in rubber, so it may perform better on the upper part of the FM band (where the antenna is shorter). Logical, right?
That being said, I found that my CM-10 (may it rest in peace, it went to that great transmitter graveyard in the sky) actually performed better on the lower part of the FM band for some reason, and it had a short, non resonant antenna as well (it was just a modified CZE sold by Decade).
What auction site was this? Is "that" auction site the one most popular that starts with E? Or the other one that also starts with E or the one that starts with F or K?
I don't see the harm in naming a buy and sell or auction site where you got something.
Ebay