Tuesday, 15 September 2015

Anytone AT-588 - new 70MHz FM rig and antenna

I have not managed to work any 70MHz (4 metre band) FM DX this year.

This is disappointing. The plan was that my 4m vertical, a Sirio J-pole, would go on top of my 6m HB9CV. But when I stood up there trying to locate the pole with the beam and the hefty 4m antenna, I decided that it was just too heavy and bulky to fit. I was using a 1.5 inch pole and a TV rotator, and it just seemed to much weight for both of them. So I tried the 2m Watson X30 on that pole and it was far lighter and easier to fit, and it will catch less wind than that long Sirio. So the Sirio antenna was left to site somewhere else.

Deleting five paragraphs of explanation, let me skip several months to the point where I found that the Sirio was not working properly, and neither was the coax which fed it. So I have put up a Sandpiper 5/8th with a ring base on top of my main mast, until such times as it can go up above the 6m beam. This is at the risk of blowing up the GaAsFET front end on my SSB set-up, or perhaps the 100W from the SSB set-up killing off the 4m FM rig. Putting two antennas on the same mast, feeding two sensitive rigs on the same band is a risk, but so far so good.


Anyway, the 5/8th works 100% brilliantly on the same pole as the yagi.
Hopefully it will last there until the other mast is ready to take it. It has a ring base, so it is quite difficult to see the "ground plane", and hopefully the 4m yagi will not "see" such a small horizontal metallic ring right above it.

Having got all this underway, I heard that the 4m Anytone AT-588 was available again. The small low band rig can run up to 50W and gets great reviews. So I bought one, and the supplier was excellent. He is based in Ballymena in GI, and he sells them on eBay for the princely sum of £118, and offers a personal service. Not only does he test each rig, he sends it by next day delivery, and he checks to make sure you are happy that they work. He only imports small batches from time to time, and they sell out very quickly.
The AT-588 may be more familiar to many as a 2m or 70cm rig, and it has appeared in those versions from time to time. This low band version has all the features of the others, including tone burst, repeater shift, DCS, CTCSS ......

So why do I need a new 4m FM rig? Good question. My existing Anytone AT-5189 has given many years of troublefree service, but it is not the easiest thing to use. For example, to alter the volume you have to push the channel control and then adjust that knob, which is not easy when you are trying to work someone (I kept changing the channel by mistake and losing them). The AT-5189  is clearly built with PMR use in mind (taxis and commercial vehicles). Selecting scan required four button presses and selecting a menu item, but then not many taxis scan the band.

On the other hand, the AT-588 user's manual starts with an explanation of how to use it for amateur stations. The 588 has a proper volume control, a better display, and a wider selection of useful options on the microphone keypad. And unlike most PMR rigs, the 588 has the S meter which the 5189 lacks. Well, S meter is not the right name, but four LED blocks, which is as good as most FM rigs these days.

I am not sure how useful 50W will turn out to be. The rig gets quite hot on the highest power. I have positioned it to get some benefit form the fan I have on the FT-817. Until I move the antenna onto a separate mast, I will stick to 25W to spare the FET in the pre-amp on the SSB rig.

The size comparison between the two Anytones is quite striking. No doubt moving the loudspeaker to the top rather than being forward facing makes a big difference to the layout. The newer rig is on the top:-
The new AT-588 is deeper, but that is not a snag in any application I am likely to use:-


Initial contacts suggest that the AT-588 maintains Anytone's reputation for sensitive receivers. Both of them are maybe a bit TOO sensitive, as both rig can be overwhelmed by HF WSPR transmissions in my shack, but then plenty of rigs have problems with that. I do insist on transmitting on three bands at once.

Most 4m FM rigs have an ancestry which can be traced back to commercial rigs rather than amateur roots. And so the otherwise excellent AKD/Garex/Spectrum rig started out as a marine transceiver, and both of these Anytones are clearly derived from PMRs. My Wouxun handhelds are the sort of thing you see on construction sites. However, all these modern rigs seems to perform much better than the old converted PMRs we used to use. From Pye Cambridges to Philips FM1000s, they were discarded after years of use and were old technology when we got our hands on them. At least these ones are modern and well equipped.

I am not sure whether to let the AT-5189 go in a sale or locate it in my car. It would certainly perform better than the handheld in the car, but permanent fixings are not easy to find on modern dashboards.

And finally a word of warning. Don't make the silly mistake I made.

Don't change the coax, the antenna and the rig all at once. Then if you cannot hear someone (because he has turned his power down and forgotten to put it back up, but I didn't know that) you won't know what to fix. And you might end up changing everything, only to find that the main problem was at the other end.

73

Jim
GM4FVM

2 comments:

  1. Hello Jim if I am in the shack I always be listening to 70.450 FM in Barrow in Furness S W Cumbria IO84JC 1/2 WAVE VERT 20 WATTS

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  2. Thanks. I am usually listening to 4m FM when I am in the shack too. 73 Jim

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