AmateurRadio.com

This afternoon I was making some measurements to try to determine the current consumption of the VX-8G (and hence estimate the battery life) and I stumbled across a rather serious flaw. When the internal GPS is enabled it remains powered all the time, even when the radio is switched off. Enabling the GPS causes the current consumption to increase by about 30mA, and that same increase is noticeable in the current drawn when the radio is powered from the external DC socket, whether or not it is charging. This level of current drain would flatten the 1100mAH battery pack in less than two days!

I joined the Yahoo VX-8R group, which is the discussion group for the VX-8G as well, and noticed that some American purchasers of the radio had already discovered this problem. I hadn’t had the radio go flat on the shelf myself, mainly because in the three days since I got it I have been using it quite a lot. But my observation does help to explain why I found the battery life was poor. Like most people I suspect I have been charging it up after an outing and then taking it out of the charger in the expectation that it would still be fully charged the next time I used it. But with 30mA being taken from the battery all the time, even a 12 hour period off-charge would result in a significant loss of operating time.

The VX-8G isn’t yet available in the UK so there is not much point in contacting Yaesu UK for their comments on this issue. It’s possible that when the European VX-8GE version arrives Yaesu will have identified the problem and fixed it. If I was reading this and thinking about getting a VX-8G I’d certainly want to receive an assurance that the fault had been fixed before buying one. And if I’d bought this from a UK dealer I would probably be taking it back. So this is really an example of where buying from Hong Kong hasn’t paid off, even though the problem isn’t the fault of the dealer who sold the radio.

The workarounds would appear to be either to turn the GPS power off from the menu whenever you switch the radio off – a real hassle which will probably result in the GPS taking minutes to get a fix each time it is switched on – or else to leave it on charge all the time. The latter would seem to be the least painful.

It is a pretty annoying fault to be stuck with. I had been thinking about getting the high capacity battery pack but having found this problem I don’t think the VX-8GR will be a keeper. I shall look with renewed interest at the Kenwood TH-D72 APRS handheld when it becomes available, though I shall probably lose a lot on the exchange – giving publicity to this fault isn’t exactly going to help the VX-8GR’s resale value. 🙁

A recent addition to the G4ILO shack is a new Yaesu VX-8G hand held transceiver. In case you are thinking that I need professional help over my addiction to hand held radios you may be right – however a week or so ago I received an email from someone who has a collection of 150!

Long-time followers of my blog may recall that less than a year ago I bought a Yaesu VX-8E APRS transceiver with GPS. However I found that the usefulness of APRS was limited by the lack of digipeaters and internet gateways in this part of the world. I decided to use a smartphone based APRS client, APRSISCE instead and sold the VX-8E shortly afterwards.

Using the cellular network instead of amateur radio has its advantages but it eliminates the interest of seeing how far a little 2m RF can go. Interest in APRS has increased in this area over the last few months so I decided to give RF another go. In the meantime, Yaesu brought out an improved version of the original VX-8R called the VX-8DR and a lower cost version called the VX-8G. So I didn’t regret my decision to sell the VX-8R as it allowed me to acquire the updated version.

One of the things I really disliked about the VX-8R was the clunky way the GPS attached externally to the radio (and the absurdly expensive fixing bracket.) The VX-8R (and the updated DR) has a number of other features that I never used and didn’t need in an HT: 50MHz coverage (including AM), short wave receive (which was useless anyway without an external wire antenna), a barometer/altimeter and a temperature sensor. Nor did I care that it was submersible. I did lose a brand new HT in the Solway several years ago, but as I didn’t immediately notice it had fallen off my belt I never found it again.

The VX-8G lacks these unwanted features and can be set to vibrate when you receive an APRS text message – a new way to get a thrill out of amateur radio! More importantly it has the GPS built into the radio which makes for a much neater package. It costs about the same as a VX-8DR without the GPS option.

The VX-8G is not available yet in the UK so I purchased it from Solid Radio, an eBay trader based in Hong Kong. This was the most expensive thing I have ever bought from a Far Eastern trader and I felt like I was taking a bit of a gamble, but the radio arrived in just over a week and with no unpleasant surprise on delivery.

The VX-8G looks very similar to its older brother but is a little slimmer and lighter. I seem to remember that the body of the VX-8R was metal, or else it had a substantial chassis that added to the weight. With the standard battery installed the VX-8G is noticeably lighter than my Kenwood TH-F7E.

The Yaesu’s GPS takes much longer than the one in my hTC smartphone to acquire a signal. In fact after waiting several minutes on first turning on the radio I started to worry that the GPS wasn’t working so I stood it out in the garden on a table where it eventually established its position. On subsequent occasions it has still taken a few minutes to fix its position which is a bit annoying.

Operationally the radio appears to be the same as the VX-8R and the menus are very similar. One of the new features is SmartBeaconing which varies the frequency of position reports according to your speed and whether you have changed direction. There are different settings for this depending on whether you are walking, cycling or driving. The original model would only send position reports on a fixed time interval. Once I had enabled SmartBeaconing it sent a very accurate track of my walk.

It is too early to say with any precision what battery life is like but initial impressions are that with the GPS enabled it is pretty poor – a criticism that unfortunately is also true of the smartphone. I used to have a navigational GPS called an iFinder GO2 which ran for about 18 hours on two AA batteries so low current consumption GPS devices do exist – why doesn’t Yaesu use them? In the VX-8 radios when you use APRS the problem of short battery life is compounded by the need to disable the power saver (which causes the receiver to listen in short bursts rather than all the time) so you don’t miss the start of a beacon or message sent by another station. The VX-8G uses the same batteries as the VX-8R and DR models so a higher capacity pack available, but it is quite expensive.

I am pleased with the VX-8G so far and am looking forward to discovering where I can be tracked from. I think APRS holds some of the same fascination as WSPR on the HF bands in that it is interesting and sometimes surprising to see how far your low powered signals can travel.

I don’t know when the VX-8G will be introduced in the UK or what its UK retail price will be but I expect it will still be quite an expensive radio. A pity, as I think the cost puts a lot of people off discovering APRS for themselves.