ICOM A6E: 12V= adapter

[Jan Olieslagers]

I was clever enough to reverse the input wires on the 12V= adapter (with car-lighter style power plug) of my brand new Icom A6E. It is absolutely FuBaR so I want another one. But I have my doubts about the factory price, and, having some skills with soldering and electronics, am wondering about an alternative.

The spec says 11V/3Amp but 11V is tricky to produce from the typical 12V system in car or (light) plane. However the A6E runs happily on 6 NiMh rechargeables, giving only 7,2 V or thereabouts.

Would it work equally well on an externally fed voltage of less than 11V? Perhaps a bit less transmitter power, but I am mostly using it for Rx only anyway. I cannot imagine I could produce any harm in the A6E itself this way, or could I?

I am aware this kind of question should go on an electronics forum rather, I did try but got no useful answers.

TIA,

[JTobias]

You can probably get a universal one from Maplin?

Joel :ok:

[Jan Olieslagers]

Thanks Joel, I took a look but no luck. I should have mentioned I had already checked with their continental counterpart Conrad with equal lack of success.

11 V= is quite exotic, that's what me wonder if any other voltage would also do. Then again at 3 amps it should produce 33W even if only for short periods. 33W is quite a lot.

But it was nice to find a netbook car adapter at Maplin's, I may be considering that for my eeePc900 running my homebrew GPS software.

[Lister Noble]

Try Icom,they were very helpful and a reasonable price when we had an old A3 repaired this year.
Lister:)

[rans6andrew]

presumably the 7.2 volt battery pack is recharged when the external supply is in use. This suggests that about 9 volts will be needed as fully charged NiMH cells will peak at about 1.5 to 1.6 volts per cell. Also, in my car and in my aircraft, the 12 volt systems are usually 13.8 to 14.2 volts when the generator/alternator is doing the business so regulating down to 11 volts is not difficult.

Rans6.....

[Jan Olieslagers]

@Lister: do Icom have an address in the UK? Would they even have one on the continent?
@Andrew: the documentation says nothing about an integrated charger, I do not think there is one, though there might be. I was thinking of testing with the classical setup of an 7809 or 7810, boosted with a PNP transistor and perhaps adding some kind of current limiter for short-circuit protection. Plus if I'm really courageous an overvoltage protection on the output, for the day the 7809 renders up the spirit.
Think the 7810 might not be really happy even with 13V input so my first idea is a boosted 7809. But I hoped for some confirmation such a setup cannot damage anything inside the A6E. It's bad and stupid enough I blew up the adapter, don't want to go any further that path...

PS I'm flying a Coyote too: OO-F75 (club-owned).

[Lister Noble]

Icom UK - radio transceivers, receivers and navigation products (http://www.icomuk.co.uk/categoryrender.asp?categoryid=3507)


Give them a call,they are very helpful

[S205-18F]

Hi I have one of the units you are talking about! It is surplus and I am sure we can come to a mutually acceptable deal!
PM sent.

[Jan Olieslagers]

@S205: PM read & appreciated & answered
@Lister: thanks for info; I am reluctant to call engineers for this little trouble of mine. Depending on further feedback, I might send them e-mail during the upcoming weekend. Then again depending on feedback, I might give them a ring later.

[chrisN]

Warning: I am not an expert, and this is second-hand from somebody who is.

The older Icom battery packs, and I suspect the one in the radio mentioned by the original poster, have clever electronics in them, which can deal either with 11-12 volts or 6-7.

Apparently, there are two sets of cells which can either be in parallel at 6-7 volts, or switched to being in series at 11-12 volts. Hence the ability to be charged at 6-7 volts, when the internal switching detects that is what is coming in and separates the two part-packs into parallel, and later automatically re-switches them into series to drive the radio itself.

AIUI.

Chris N

[Whopity]

The spec says 11V/3Amp Thats 33 watts, a bit heavy for a handheld. Most handheld radios will work quite happily from a nominal 12 v supply which is typically 14 volts. Transmitters get a bit warm.

If you really want 11 volts there are plenty of three terminal regulator ICs that will give you that voltage. The 7810 is OK to 1 Amp. Usually you can set the output by changing the series resistor in the ground return.

I am surprised your old one doesn't have a reverse polarity protection diode in series with the supply. Usually you just pop a new one in and all is OK, check it out before you buy a new one.

Apparently, there are two sets of cells which can either be in parallel at 6-7 volts, or switched to being in series at 11-12 volts. Highly unlikely, a series regulator or current limiter is all that's required and is often built into the battery pack..

[DBisDogOne]

Would have thought a 12V one of suitable current rating would be fine. That's what I've used in my ICOM A6 - it works fine, wired or batteries. Make sure it's regulated though.
Companies love making PSU's with odd voltages (just look at laptop PC's for some obscure voltages!) so when folk bugger up their PSU's, they aren't inclined to go to Maplin or CPC or RS etc for a cheap replacement.

[rans6andrew]

it does seem that Icom have shot themselves in the foot with this range of radios. All of their previous units have just taken 12 volts (max 15 or 16 volts) straight in. Nothing complicated needed, just a cable with a power jack connector at the end. Just like the Vertex radios do, and they are cheaper!

What were they thinking?

Rans6...

[Whopity]

Why not use the ICOM DC power lead:• CP-20 CIGARETTE LIGHTER CABLE WITH DC-DC CONVERTER For operation and charging with a 12V/24V cigarette lighter socket.