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====== Yaesu FT-857D ======

A 160m to 70cm, all mode, portable, 100W radio without a tuner. Great for high-ish power portable paired with a fairly chunky battery, and resonant antennas.

===== Technical =====

==== RF out ====

It is fairly straightforward to add an SDR output to this radio, with an inexpensive [[https://www.sdr-kits.net/index.php?route=product/product&product_id=162|HupRF Panoramic Adapter Tap (PATV)]] Board or similar, which is just a small buffer amplifier. Using this board you can directly connect something like an SDRplay RSP and watch whole bands at a time, including setting up click-to-tune etc.

==== Filter failure ====

The FT-857D has an issue where ceramic filters go bad and the receiver fills with crashes, even with no antenna connected. Apparently this is due to a design error. If yours hasn't failed yet, prevention is possible, see {{ :radios:ft857-897_cf1005-fix.pdf |}}. Apart from the symptom, a Yaesu technician reports that if your filters have a "dusty" or "hazy" appearance, it is likely they have failed / will fail soon. 

The filters are the three cubioid components by the audio jacks on the back, visible if you remove the top cover of the radio.

Technofix [[https://shop.technofix.uk/pack-of-3-ceramic-filters-ltm455h-ltm455e-ltm455g-for-yaesu-ft-857-ft897|currently sell a kit]] of replacement parts if yours is too late. 

Replacing them is a matter of removing the main board, desoldering, replacing and reassembly. Removing the main PCB requires removing the front plastic section, by removing four somewhat hidden screws from behind the front panel.

From left to right, as per the board text, the filters are numbered CF5, CF2, CF3. My CF5 is marked TOKO A55HR, my CF2 is marked TOKO A55EP, and my CF3 is marked TOKO A55GS.

The components I have been supplied are marked CFWM 455E, LTM 455GW, LTM455HW.

From Technofix:

1 x LTM455H 455kHz IF ceramic filter\\ 
Replaces LTM455HW, CFWM455H, ALFYM455H\\ 
6kHz 6dB bandwidth, commonly used for AM

1 x LTM455E 455kHz IF ceramic filter\\ 
Replaces LTM455EW, CFWM455E, ALFYM455E\\ 
15kHz 6dB bandwidth, commonly used for FM(W)

1 x LTM455G 455kHz IF ceramic filter\\ 
Replaces LTM455GW, CFWM455G, ALFYM455G\\  
9kHz 6dB bandwidth, commonly used for FM(N)  

For me, CFWM 455E is CF2, LTM 455GW is CF3, and LTM 455HW is CF5.