The bhi DSP Noise Cancellation kit for the Yaesu FT-817ND is really a great addition to this well known popular transceiver on the market.
The DSP works at the audio stage, not at the IF stage like most modern transceiver today. But, like the Elecraft K2, the DSP at the audio stage could also add an excellent result to reduce the noise.
The kit includes everything needed, less the tools of course. It also comes pre-wired and ready to be installed by the user.
The first real step, after removing the internal controler board, screws and cables, consist in removing a surface mount resistor between the internal audio amplifier. So this way, the DSP kit will be inserted into the transceiver audio chain.
You must be very careful when removing the resistor. It is indeed very small. I suggest that you try to save it for the futur…. if you can. You will be able to re-install it if needed.
Soldering the wires is quite easy. But you must take a special care to not move the wires uselessly. Keep them steady as possible… it could be very easy to take off a board trace by pulling to hard on the wires by accident.
Another step is to drill the upper cover of the transceiver to let the DSP button be installed and accessible by the user. You must take care to drill at the exact position. Take a ruler that have millimeter graduation, it is more precise that fraction of an inch.
The board position inside the FT-817ND is not very critical, but you must take care to properly position all wires and to avoid obstruction that could be made by one of the wires that could be stuck between internal parts when reassembling the transceiver. Do not hesitate to reduce the length of the wires if they are too long. In my case, I cut by a few inches the red wire that power the kit from the transistor. The picture above unfortunately does not represent my final configuration of the red wire. If you are planning to add an additional ceramic filter, it is recommended to install the board at the location shown below.
The final step is to reassemble the transceiver.
The result is very interesting. The DSP kit is very easy to operate. Be advised that, even when disabled, the DSP will always draw a few amps. So with or without the use the DSP feature, your transceiver will at the end draw a little more current than initially, approximately 10-20 mA. Not a bad news, but you better know it.
The result looks like almost the same as if it was done directly by the manufacturer.
I hope you will enjoy it like I enjoy mine.
A really nice addition to a really nice transceiver…. even in 2016!