HP 8481A - A2 Assembly Replacement and Soldering; Connector Cleaning

HP 8481A/82A/83A
08481-90049
Damage can occur to both the cartridge and center conductor if they
are not properly mated. If no springlike action (or “give”) is present
remove the cartridge assembly and rebuild the center conductor with
new parts.
Caution
14. Tighten the cap nut to finger tight then torque the cap nut to to 35
±5 in-lbs (395 N-cm).
15. Reassemble the power sensor using the rea.ssembly procedure at the
end of this manual.
16. Test for SWR.
17. Check the FET balance using the procedure prior to Replaceable
Parts. (If you were careful not to disturb the wires above the PC
board (A2) this step may not be necessary.)
18. Calibrate the Sensor using your HP 11760S Automated Power
Sensor Calibration System. Place the new sticker on the Power
Sensor cover.
A2 Assembly Replacment and Soldering
To replace the A2 printed circuit assembly, you will have to perform
some soldering to remove and replace the wires from Connector Jl.
Remember the Power Sensor is a highly sensitive device. As such, it is
affected by very small temperature differences between its components.
After doing any soldering in the unit, wait several hours for the unit to
reach thermal equilibrium before using or testing it.
1. Use a temperature controlled 600°F (311°C) with a zero crossover
tip.
2. Use a low temperature RMA flux SN 62 solder.
3. Do not attempt to remove flux residue from around solder joints. We
have found that using a cleaning solution spreads the flux in a thin
sticky layer over the entire assembly.
Connector Cleaning
Keeping in mind its flammable nature, a solution of pure isopropyl or
ethyl alcohol can be used to clean connectors.
22