Panasonic RF B65 shortwave

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ChristopherJensen

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I bought this about 20 years ago to carry during Desert Storm. It has worked great. Until now. The batteries are good but it flashes "E" when I turn it on.

The owner's manual was lost and I haven't been able to find one on line.

Panasonic "support" says they don't handle stuff that old.

There was one mention on line about a reset feature but I sure can't find one.

Any thoughts?

Thanks.
 

K7MEM

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A service manual is available at the following link.

Panasonic RF-B65D Service Manual PDF Free Download

It does contain a couple of pages on operation.

Did you replace all of the batteries? There is a 3 Volt battery that is backup for computer and clock. Sometimes when these go dead, they can be recharged by leaving the unit on for a while, and then doing a reset. Otherwise, you could just replace the backup battery.
 

ChristopherJensen

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Panasonic RF B65

Thanks very much. I appreciate it.

I didn't know it had a 3V.

There is a place for two AAs I assumed were some kind of backup in addition to regularly taking 4 AAs.

If I may impose on your time once more, where is the reset button?

Finally have you downloaded manuals from that site without anything bad happening to your computer?

Best regards,

Chris Jensen
 

K7MEM

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Yes, the two AA batteries provide the 3 volts for backup. But looking at the service manual brought up another interesting item.

The micro-controller in that unit (IC-202) has input pin that checks the system voltages. It says in the manual for pin 20:

"Battery 4 V check input terminal. Monitors in intervals of 100uS. If low for 3 consecutive times a flashing "E" is displayed and 7 seconds later the power is switched off."

The circuit that drives this pin is a comparator that checks the 6 volts and the 3 volts. As long as they are within limits the comparator output is in range and the "4 V" check is satisfied. It is possible that one of the diodes, or even the electrolytic capacitor in the comparison circuit are bad. If you can read a schematic, and have a volt meter, the circuitry could be checked. I would double check the batteries and make sure their contacts in the battery compartment is good.

I read through the section that describes the controls, but I didn't find anything that referenced a master reset. The micro-controller (IC-202) does have a reset pin but that is controlled by a electrolytic capacitor charging through a resistor. That means the micro-controller is reset every time you turn the unit on.

I looked at the schematic and didn't see any hidden reset. However, sometimes they use a special key sequence to trigger a complete reset operation.

As far as the download, I have have no problems. That same Service Manual is also available at:

mods.dk -> Instruction, users and service manuals for Panasonic

but to get the manual on that site, you need to generate a login. I can put either one of those manuals on my own web site and send you a link, if you like.
 

ChristopherJensen

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misbehaving rf b65

Thank you very much for spending so much of your time - and expertise - on this.

I dug through a bunch of stuff and found the manual. It was no help. I also downloaded (thanks) the service manual. But I don't know squat about electronics. So, I'll look for somebody who may be able to repair it.

Best regards.
 

Boombox

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I have an RFB45 (the next Panasonic model) -- awesome radio. Only time I get an E is when batteries are dead. It's possible your battery terminals are corroded, dirty, or possibly it wants alkalines instead of HD batteries -- no problem with that in my radio, but it could be worth a try.

Also, it could be a weakened solder joint on one of the battery terminals -- esp. the one with the spring (usually the negative terminal) -- the spring over time puts pressure to the solder joint and it can weaken. This happened with my DX398. All it takes is re-hitting the spring terminal's solder pad w/ an iron or gun.

To reset your radio, try taking all batteries, power adaptor, etc., out for half an hour or more, then put them back in. Works on many other radios.

There is a Panasonic Yahoo egroup with a few guys that are good with all Panasonic portables (Panaport egroup), you could always ask for advice there, too. I don't go there much since Yahoo changed things, though...

Good luck.
 

ChristopherJensen

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Boombox: You were absolutely correct about the terminals. I cleaned the non-spring ones with a bit of rubbing alcohol and it came back to life. Thanks very much for saving my radio. Best regards.
 

Boombox

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Very glad I could be of some help!

My Panasonic RFB45 is one of my mainstays, actually. My best over all radio. Very easy to use, and it's Excellent on MW -- possibly my best. Very good on SW and SSB. Seems built like a tank.

The RFB45 was the last Panasonic made digital SW radio -- it was the next model produced after the one you have, the RFB65, which probably is a better radio.

The RFB65 has similar circuitry to my radio but it has an extra stage or two of IF amplification which my radio doesn't have, which gives the RFB65 an edge (I don't have a 65, I've just seen the schematic and talked to a guy online who had both radios).

So it's an excellent radio you have. One guy on the Panaport egroup says he thinks it's better than nearly every other digital SW portable he's had (not sure if he was referring to some of the newer Tecsuns and other models, though).

Just keep them terminals clean and rock on!

73
Chris
 
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