Thursday, June 13, 2013

Kenwood D-710 backup battery change

Apparently the Kenwood D-710 APRS dual band transceiver has a back up battery for the clock.

Your memory and presets don't need it, but the clock on the display does...and probably it uses that clock for APRS time date stamps on reports.

At some point in the last few months mine died.  I didn't realize it until I noticed that the clock just showed blank lines


Then I went about trying to figure out where the battery was, what kind it was, etc.   Suprisingly harder to find out than you would expect for a replaceable item.

Long story short, I found some schematics and diagrams for the unit.  I searched for a battery and eventually found it.

It is a tiny rechargeable lithium battery mounted in the remote head.

Specifically it is a Sanyo ML614 battery, just a button cell, no solder leads (both kinds are available).

 It isn't something you will probably find locally, I found it online at a few electronics supply stores, and with shipping they were all around $8.   I ordered mine from Radio Shack.

Wednesday, June 12, 2013

Fix your Netgear Wall Wart Power Supply (switch, router, etc)

This is the second Netgear wall wart that has failed on me...and probably my 6th or 7th wall wart total.

Even though it is under warrantee...Netgear wants you to spend money to get it replaced.

They are willing to send you one for $20, or you can mail yours and eventually get one back (that is what I did with my previous one)...shipping cost about $4, for a really poorly built power supply.

All that is inside the plastic box is 4 diodes for a full wave rectifier bridge, and a cap connected to the step down transformer, no voltage best it cost them a buck to build.

So when the 'customer service' person told me he would take care of it right away...just needed my credit card...I said forget it, I will buy another piece of junk from the dollar store first.

That is when I decided to pop it open.

Not impressed.

This was the offending part, a bulging capacitor (hard to see but the top is bulged a bit.

Radio Shack only had axial lead in this size 2200uf 35v (original was a 25v, close enough)

So a bit of heat shrink tubing solved that issue...and for a few bucks it was back up and running.