On one of my last trips to this site I noticed a failure with one of the power amplifier modules in the newly installed transmitter.  The manufacturer has sent a replacement part and now I need to install it before snow completely shuts me out of the site…

This time I needed the chains on UW88 to access the site…It really is getting tough and I won’t be able to do this much longer without a snow vehicle… 

Snow king is starting to look even more snowy as the season goes on…

The failed power module is removed for service…

These modules consist of 9 individual amplifiers…One amplifier is split to drive the other 8.  These 8 amplifiers are then combined to produce the total output power from the module.  Quite a nice design with a considerable amount of internal redundancy.  The transmitter is actually still on the air and making very close to full power even with this entire module removed.

Power amplifier #7 from Module #2…There is no obvious evidence of a failure but many times failures occur without any external sign of damage.  Thankfully the onboard diagnostics told me exactly where the fault was.

The new power amplifier board…A tag indicates several parameters and adjustments that will need to be configured in the transmitter for optimum performance.

The old amplifier board is removed–This required *gasp* picking up a soldering iron to disconnect several leads attached to the board.  Sadly this level of repair is becoming less common in the field…Component level repair is becoming even less common.

The replacement board is installed and ready to go.

Next step, reassemble the module and test.

Once again while at the site I perform some additional wiring cleanup.  One step at a time…Note the neatly dressed cross-connect wiring between the top punch block (various equipment on site and in the rack) and the other four (remote control and audio switcher).

Time to head back home…until next time.