Kenwood TK-941 Filter Changeout
If you are changing out the filters on your TK-941 I hope that you are doing so to make a repeater receiver or link radio out of it! This radio, due to its fixed offset of -39MHz would be a waste to change out the receive filters for non-repeater receiver or link radio use. The TK-941 does not need the existing receive filters centered at 938MHz changed out for use at 927Mhz. The receiver front end filters in the TK-941 need to be changed out to receive at 902.xxxxMHz for repeater receiver use and they are very similar to the TK-981 filters.
There are 2 ways to accomplish the change out of the receive filters on the TK-941 you can remove them while the RF board is still in place or you can remove the entire board from the chassis which would allow more access to them- this is a lot more work. The front end of the TK-941 contains 2 SMD filters which are 3 poles each. They are easy to remove using a hot air SMD re-work station, as you can remove the filters entirely with no-damage to the traces on the board in around 1 to 2 minutes. The filters are a lot more difficult to remove using a normal soldering iron. I have done both methods and the way to go is hot air. A good alternative to purchasing a hot air rework station is purchasing something you can use much more frequently, a butane powered soldering iron with the diffuser (nozzle) tip attachment, I have used the Master Appliance Iron model number UT-100SI with great results; do not use anything smaller than this as it does not provide enough heat- see picture of unit below. Another way to remove the SMD filters is using a high power iron in the 100W to 150W range, and heating and removing the filters section by section- this works but you have to be VERY patient and use a VERY HOT iron.
Pictured below is removal of the original TK-941 filters using a Master Appliance butane soldering iron model number UT-100SI with the diffuser (nozzle) tip attachment. The only side effect of using a butane soldering iron with the nozzle tip is you will notice that condensation will form on the aluminum chassis as you are removing the filters!
TK-941 with 2-pole 915MHz Thru-hole Murata filters installed.
