The FT-817ND is a little and versatile all-band multi-mode transceiver which I am using routinely during SOTA (Summits-On-The-Air) activations. Although the little radio is already quite capable in it's default configuration there are several tuning options available. One of these is the integration of the mechanical YF-122S SSB mechanical filter with an bandwidth of 2.3 kHz. The advantage of using this filter is the ability to better suppress strong signals on adjacent channels.
The integration of the filter is already perfectly described in the manual (one could only wish that manufacturers of other electronic products would provide such detailed instruction manuals) and I do not intend to replicate those instructions here. However, I've made a couple of fotographs during the build process which I would like to share with you. The first step is to ensure that the radio is complete without power which requires the removal of the NiMh battery.
The next step requires the top lid to be removed. One has to be careful to not puch too much strain on the speaker cables unless one wants to risk damage to the speaker-pcb connection.
The following picture provides a closer look on the top main board. The place for installing the filter is on the top right corner of the pcb.
The filter comes in a nice little cardboard package and is labelled YF-122S ...
... which leads to a little surprise when opening the package and finding a filter labelled XF-119SN. Fortunately those two filters are the same in term of package and filter characteristics.
In order to install the filter one has to insert it with the description sticker facing upwards Since there are 3 pins on one side and 4 on the other it is difficult to wrongly insert the filter.
The last step is the activation of the filter within the radios software. Enter the secondary menu level by pressing "F" button for 1 s. Rotate the "SEL" knob until you reach manu #38 "OP FILTER". By rotating the "TUNE" knob select "SSB". You can leave the menu by pressing "F" shortly again. Congratulations, your SSB filter has been successfully activated.