Many thanks to an SWLing Post reader who recently asked the following question:
Hi Thomas:
I rely on my SONY Shortwave in case of emergency, but it’s occurred to me that relying on the alkaline batteries inside to be fully charged and not corrode wouldn’t make sense.
I am thinking it would be great to be able to power the radio’s 6V 700ma off of the multiple USB rechargeable power sticks I have around the house.
What I need is a cable from the USB stick to the radio.
As a hobbyist project, any ideas for an existing cable or how to make such a cable with the appropriate power circuit?
Many thanks.
I know a power cord can be created as long as polarity and the coaxial plug match what the Sony requires. I’ve never used the Sony on a 5 VDC source–I assume it’s within tolerance and RX sensitivity wouldn’t be affected?
Post readers: If you’ve ever created or purchased a USB power cable for the Sony ICF-SW7600GR, please comment!
I am looking for rechargable batteries for sony icf 7600 gr plz guide. how much mph required . Thanks
Tried USB power source last year on my ICF-2010 (it needs 4.5v and negative tip to a standard 2.1mm plug). It was too noisy to use for DX but local listening was fine.
Here is a better idea for you – since you need 6 Volts you can custom make your own battery pack (and safer than being forced to use lithium batteries in a kludgy holder). NiMH are 1.2V * 5 = 6V. On eBay, buy a “Velleman BH363B BATTERY HOLDER 6x AA-CELL SNAP TERMINALS”. It should come with a snap terminal connector that you can solder wires to. Then buy one “dummy” AA that takes up the extra space (I like the overpriced Ultracell which seem reliable).
You will use 5 NiMH rechargeable batteries (I like PowerEx versions) and one “dummy” AA in the 6x holder. Then all you have to figure out is how to connect this to the radio. Does it use a standard 2.1mm x 5.5mm plug??? Sony usually uses a NEGATIVE tip but not sure about this particular radio. You may want to super glue the insulation of the snap connector to an empty portion of the side of the 6x battery holder just because these cheap Chinese wires are fragile and thin, then wrap the wire you solder to it around the holder for more sturdiness when traveling.
If you need more capacity, you can use a D-battery holder and use the D-cell to AA-cell adapters that hold three AA batteries in a D-cell sized adapter. All on eBay. Have fun with it!
Great suggestion, Tom. I think going with D cells (as you suggest) would give you months of battery capacity!.
-Thomas
Given that the ICF-SW7600GR takes 4 x AA cells (i.e. 4 x 1.5v = 6v) but by all accounts runs happily on 4 x NiMH AA rechargeables (i.e. 4 x 1.25v = 5v), you’d have to guess that voltage-wise it’ll work OK. But, as Owen says, most powerbanks use 3.6v Li-ion cells + a boost converter to produce 5v, and those are (usually) pretty noisy.
Still, I’d try it. As Tudor says it’s not hard – grab a cheap USB cable, cut the end off, stick the appropriate barrel connector on. There’s also plenty of USB->DC barrel connector cables in various sizes available for cheap on eBay/Amazon/etc, but be careful it – most don’t specify polarity, but I’d bet they’re centre positive. The Sony seems to be centre negative.
I made a DC cable to power my Perseus SDR from my laptop’s USB 3 socket, by a similar method to Tudor. It works well. It is no different in principle to power a portable radio from a laptop or a USB power pack, although as stated noise could be a problem.
It’s not difficult to cut a USB cable and solder a DC plug to the +/- 5V wires coming from the USB connector (a Google search will help to identify which wire is which). I did it for a Newstar DRM radio and it worked fine. But for the Sony it’s much easier to just keep a pack of alkalines nearby and use them when needed.
It might be interesting to see if a radio that wants 6 volts can be powered by only 5 volts.
Some radios (i don’t know about this particular one, though) will power themselves off when the supply voltage drops below a certain level, so this may not work.
If your wanting to use the ICF-SW7600GR for shortwave listening, then using a ‘USB rechargeable power sticks’ is likely to prove frustrating. I think most of these employ a buck-boost type of circuit,
in order to regulate the output voltage. Unfortunately, these circuits are usually pretty noisy in the RF spectrum.