Kenwood TS480HX TCXO install.

Photo Credit: Kenwood USA

 

 I was getting a bid annoyed with my 480 drifting around with temperature fluctuations in the truck, so in goes the SO-3 TCXO.  It wasn't as simple as the 590SG, but not really any more difficult.

 Right there is the board that must be removed.  Lift the white connectors on each side, they are tight, a flat tool of some kind working on each side a little at a time and they come up.  Remove the three screws and the board will lift right out.

 Above is the bottom of the board with the TCXO partially soldered.  I wanted to show how I held the unit in place by slightly bending the tabs in.  You may find another method works for you.  Solder each of the four pins AND both tabs of the case.  I use an isolated pen with a smallish tip at about 760F.  Solder flowed well if you use good technique, ie. heat the joint then apply solder.  I let the tip set on the tab to heat the large thermal mass of the case a bit before moving to heat the solder pad and then applied solder.

 And there it is, all soldered and ready to go back into the main unit.  Do be cautious, as you can see here, the pins are close on the right side by the pin header, and there are SMD's on the left side.

 Above, you see the jumpers R103 and R104, these must be cut.  I chose to remove a small section of each instead of just making a single cut.  This is so the rig uses the newly installed TCXO and not the stock XO and TCXO simutaneously. Imagine the radio trying to use two standards at once...one can not serve two masters!

Below is the board in place with the new TCXO and ready to be zero beat with WWV.  I used my Hermes Lite 2+, Thetis has a built in calibration function and 20MHz was strong.  I tuned the Hermes a few hundred Hz high on LSB, set the 480 to the same frequency in LSB as well.  Then it is a matter of listening to the beat frequency and zeroing it out.  Use a good speaker system that can reproduce tones smoothly.  You will hear that famous wow, wow, just adjust to make it slower and slower until it disappears. Just as with the 590, it's the same TCXO, the adjustment is extremely touchy, so go very easy on the little tool.  If you think you are applying pressure, you are moving it.  Do let the radio sit on for several minutes so the TCXO can stabilize as much as possible before trying to zero beat.

 No, I didn't go into opening the case and removing power cords and that.  I figured if you are brave enough to do this project, you can figure out how to get to the inside of the rig.