13 July 2006

mailbag #1: sw7600gr ac adapter

Here's the first episode of the Cobalt Pet mailbag. A reader from Indonesia wrote in to ask about power adapters for the Sony ICF SW7600GR.

I just purchased Sony ICF-SW7600GR at the end of 2005. Unfortunately, the receiver didn't come with its original AC adaptor called "Sony AC-E60HG" (sold separately and now discontinued).

So far, I've been powering the unit with NiMH rechargeable batteries, but I'm still not satisfied with the unit's performance due to the following results:
1. When the batteries get weak, my reception suffers/sounds noisy.
2. The tiny volume (sound isn't room filling).

Anyway, the original adaptor AC-E60HG was also dissapointed. I found many reviews that it introduced noise/hum against the SW band (maybe this was the reason behind it's discontinued?).

So, we would like to know, how are you solving this general problem for any 7600GR users.

Thank you.

Derin, Indonesia


I use NiMH batteries in my own SW7600GR. It's interesting to hear of the noisy reception issue with weak batteries, which I didn't recognize. The voltage of rechargeable batteries is 1.2 volts, which is 20% less than a 1.5 volt alkaline battery. Batteries will provide less voltage after use. Even a weak alkaline battery can provide more voltage than a fully-charged NiMH battery.

If you have been in the habit of running your rechargeable batteries in the radio until the radio won't power on anymore,
consider periodically measuring the voltage of your rechargeable batteries. If the measured voltage falls below a certain level (such as 1 volt), then consider moving the rechargeable batteries into a less sensitive device like a flashlight until the batteries fade away. Keep a second set of rechargeable batteries around so that you can put fresh ones in your radio when the current batteries are too weak.

On the AC power side, Sony's original adapter for the SW7600GR was reported to introduce interference. Universal Radio, a mail-order radio company in the USA, offers a power supply for the Sony ICF SW7600GR: MW 41-680 power supply. This adapter provides 6 volts DC, 300 milliamps, is filtered, and is not known to cause interference. I wrote to Universal to get a shipping estimate for Indonesia, but unfortunately they do not ship to Indonesia at this time. If you want their power adapter, you may need to be creative in order to obtain it. It is designed for 110 volt AC outlets, so I assume you would need a transformer in order to use it in Indonesia.

Would you like your question or comment addressed in a future mailbag article? Post a comment for this article and I will try to respond. Thanks for reading!


Derin said...

Hi cobalt pet,

thanks for your effort in contacting "Universal Radio" for asking possibility of shipping MW 41-680 to my country. I really appreciate it.

So, for now maybe i better try your rechargeable batteries tips.

If you take a look ICF-7600GR webpage, you would see that Sony has replaced AC-E60HG with the new "AC-E601" (it comes with the portable if you purchase in Japan Sony branches only).

Anyway, my japanese friend, Moyashi Inoue using another Sony adaptor called AC-E60M. He explained me with email that this adaptor works excellent with the portable without hum/noise. Unfortunately, it's also only sold in Japan.

Still, powering ICF-7600GR is the most interesting issue to discuss :).

weatherall said...

Thanks for the Sony tip too. I made the assumption that Sony was no longer providing any adapter for this radio. When I ordered my SW7600GR, it was out of stock on the Sony website but Universal Radio had it.

By the way, have you looked at the SW7600GR group on groups.yahoo.com? You may find additional ideas there. Good luck on solving this problem.

Anonymous said...

I use a Sony AC-E455A adapter which can be found for cheap on ebay.

These are 4.5 VDC 500 mA adapters which according to a couple of users (see http://groups.google.com - search for: AC-E455A Sony):

"... have the correct plug and polarity for the 7600GR. Measured under load, they produce just a hair over 6 VDC. The AC-E455 was originally sold for the Sony Diskman ... my 7600GR [has run] quite happily with four different samples of the AC-E455 and AC-E455A. No hum observed."

I can verify hum-free operation using the AC-E455A. The Sony AC-E455 is also a good choice.