Time For Some Yaesu FT-857D Bling…Adding A Somewhat Homemade 500Hz Rockwell Collins Mechanical CW Filter (526-8693-010; YF-122C)

I told you exactly how to do this for the Yaesu FT-818nd here. In essence you need to acquire a custom made printed circuit board from a man in Poland and you need to order a filter on Ebay from Japan. Then you solder the two parts together in 3 places. That is it! The total cost will be under $150 were you to do this today.

On the other hand, if you want to purchase a pre-built filter, I did find this one on Ebay tonight. It is the only YF-122C (Yaesu’s official part code) currently on ebay. This is more than half of the current cost of a brand new FT-818ND transceiver. And if you were even considering a 300 Hz filter instead, don’t bother. I no longer believe in their existence. Furthermore, if you are thinking that you don’t need one, you are being short-sighted. CW is not a usable mode without the narrow filter in my opinion.

So, this brings us to the FT-857D. After successfully assembling and installing the filter into the FT-818ND, I wanted its big brother to have one too. So, I ordered another filter, and let it sit around for a few weeks until I was finally ready to tackle the project.

Like my 818, the 857 has Portable Zero protective rails installed.

These were removed first simply by unscrewing the 4 screws that hold them in place.

Here you can see the rail attachments better. The arrows are pointing to the smaller screws that hold the cover in place on the radio.

Next remove the face plate of the radio by disconnecting the modular connector.

It is now time to open the transceiver. Seven screws hold the cover on to the rest of the chassis, with 3 on top and 2 on each side. Remove all of these screws.

Sure looks a bit sad, sitting there like that doesn’t it?!

But really what I want to show you is that you need to slide the cover backwards in order to separate it from the overlapping area of the chassis in the front of the transceiver. The cover tucks ever so slightly underneath the face plate attachment section.

Now lift the cover off, but be gentle. The speaker wire is attached by, ummm, yellow tape, to the lid. You do not want to rip it apart in a moment of carelessness.

Now I soldered the 500 Hz filter to the custom PCB. Remember, you can learn all about that in this post.

As with the 818nd, it is immediately obvious where an add on filter goes.

And not to mention, they are labeled essentially optional filter 1 and 2.

Another view shows that each filter placement site has 3 pins on one side and 4 pins on the other. And guess what? So does the filter!

Here you can see the filter in place in the FIL-1 spot.

Another angle….

And yet another view…

Time to go into the menus of the 857. The transmit IF filter (menu item #86) should remain on “CFIL” for the native 2.4 KHz ceramic IF filter

Next, switch menu item 64, the “OP Filter 1” to FIL1. This makes your newly installed filter the optional filter.

Here is a portion of the Yaesu FT-857D manual. Notice that the multifunction row of the 857 will have a group with “CFIL”, “N/A”, and “N/A” before you insert your filter.

However, after installation of the filter and changing menu item #64, you will now have the option of choosing the 500Hz filter.

I was able to put the radio on the air and listen to some CW transmissions as I toggled between the 2.4KHz ceramic and the 500Hz mechanical filters. The amount of noise decreased with the narrowing of the bandwidth and the cw signals were much more isolated with the 500 Hz filter as expected.

So far these DIY filter assemblies seem like a great deal!

As always.

KM1NDY