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Yaesu 857D MARS MOD

So recently I decided to give MARS a try. I used to help out with the MARS station at Camp Lejeune and aboard the USS Gunston Hall back in the mid 90’s. One of many of the requirements of operating on MARS frequencies is broadbanding my equipment. I purchased a Yaesu FT 857D in December 2010 to have a nice mobile HF/VHF rig. There is information all over the web about how to broadband this radio to enable transmit outside of the Amateur Radio bands but I never could verify any of the information as my radio seemed to have been set up different that the ones mentioned in the mods.

One mod suggested removing removing some solder jumpers that didn’t exist in my radio. Some mods mentioned using software to reconfigure the firmware of the radio to allow the mod to work. I never tried these mods in fear of bricking my still under warranty radio. After putting the mod off for a while I figured I would look back into it and see what could be done. That’s when I found this thread on . The images that they uploaded were exactly how my 857D was set up. Here is a pic of my jumpers before the mod. Click on the image to expand it.

Location of Jumpers before Mod.

Location of Jumpers before Mod.

And here is another pic of the jumpers after completing the mod.

Location of Jumpers after Mod.

Location of Jumpers after Mod.

After completing the mod, I had to hold down the F and VM keys down while turning the radio back on. Of course this reset the radio and removed all of the memories, but I didn’t have a whole lot saved in there to begin with.

I have since tested that the radio does in fact now transmit on MARS frequencies and I don’t get that ever so annoying TX ERROR flashing message anymore.

4/4/2015 Update: I just updated the photos with info on where the original jumpers were and where my aftermod jumpers were. When I used the numbers 1-9, those are my numbers simply counting from left to right with the radio orientated the way that I have it in the pics. I have no idea what the names of those jumpers are in the schematic. As you can see from the comments below, this mod may or may not work for your particular radio. It’s been 3 years since I posted this page and it gets the most hits on my site so I hope it helps some of you out.

62 Responses to Yaesu 857D MARS MOD

  1. DaveNathanson

    Thanks! My USA Yaesu 857D (serial number 5H440xxx) had only these jumpers: 2, 1.
    I want the Mars/Cap & full HF mod, so it will Rx & Tx on these freq: 1.8-56MHz, 137-164MHz, 420-470MHz

    Removed jumpers 1 & 2. Added jumpers 9,8,7. Reset by holding in Func & V/M while powering on. Many memory locations would not accept input, couldn’t use them. Added a jumper on 6, and reset again. That is fixed. Tested by transmitting on 467.650 which worked great now, and did not Tx before mod (radio display said: Tx Error). When using CHIRP to reload memories after mod, I must download from radio, import CSV of memories from previous saved set. Must select Yaesu 857, NOT 857(USA) as it used to want.

    Before Mod: Jumpers on 1,2 only.

    After Mod: Jumpers on 6,7,8,9 only.


    • Steve

      Thanks Dave! It’s amazing how many different variations of the mod exist depending on the build date of the radios. The S/N of my radio starts off with OJ2606XX and I bought it brand new from HRO back in 2010. I’m glad you got it working though! Steve

    • Ed Puckett

      I had a friend of mine do the mod as you described, but the 2 meter frequencies would not let me insert repeater tones and offsets. is this the problem that you had

      Thanks Ed

    • Dale

      I have done the mod but do not seem to be getting any of the additional frequencies. I cannot tune to 420 or above 450 for instance. It starts at 430 and then when I try to tune down it jumps back up to 450.

      Is there something in the menus or via the cloning software that I need to set to open up the additional freqs?

  2. anthony

    Hey ed i have the same problem did you find out whats wrong. Mine sends the tone to tx/rx on all frequencys but dose not open repeaters


  3. Tony

    Your mod works great! Thank you. It also expands VHF and UHF Transmit.


    • Steve

      Great Tony! I’m glad it worked for ya! I can’t take personal credit for the mod. I just happened to try it and it worked for me as well so I wanted to make it available to anyone else who might run into the various other mods out there. My 857 is still functioning flawlessly, knock on wood!



  4. Tony

    Hate to bother everyone, I have an 857d on the way in. Does anyone have the latest jumper configuration for the Mars cap mod. I have seen 6 different variations.


  5. Tony p

    Well I gave it a try. Now the unit will not even let me tune out of band let alone trasmitt.

    Any ideas


    • Steve

      Hey Tony, Sorry to hear that it didn’t work out. There are numerous variations of the mod depending on how old the radio is. Did you see Dave’s post above? His jumpers were different than mine. I tried finding a list of the different mods but I never found anything complete. Did you try the master reset after performing the mod? If so and it didn’t work, can you put the jumpers back the way they were and perform another master reset to see if you can get it going?

      Steve KU4BY

  6. Tony P

    Get it. The rig is brand new. Just came in from HRO. Thank you for the leads and concern.

    The new config is 2,3,6,7,8,9. Oh and don’t try to solder anything. The conductors are so thin any heat will cause the tracers to break off.

    Use circuitworks conductive paste and give it 6 hrs to dry.

    Thanks guys

  7. Tony p

    Sorry auto correct that should say Got it.

    • Steve

      Thanks for the update Tony and I’m glad you got it straightened out! So your mod ended up being different than mine and Dave’s after all. There’s no way Yaesu is changing the circuitry between all of these revisions of radios so there must be changes in the firmware that dictate where the jumpers must go. Maybe I’ll make another page devoted to the different mods out there on the Internet as this page might just end up confusing people instead of helping them.

      As far as the soldering goes, when I did my mod 3+ years ago, the traces were fine to solder on as long as you don’t hold too much heat to them for too long but that goes with any solder trace. I’m not sure if they have started using thinner traces or not but it was perfectly fine to solder them back then as long as you were careful.

      Thanks again for the update!


      Steve KU4BY

  8. stacey

    Hi Guys I had a friend talk me into the mod he soldered the ones in the pictures but removed the components in position 2 and 3. now I can not go over 146.000 it just rolls back to 144.000 any suggestions? and none of the frequencies opened up.

    • Steve

      HI Stacey, on mine, the jumpers at 2 and 3 needed to remain connected. Those components are just jumpers. You might try putting those back or creating a solder bridge there and see if that works. So I ended up with jumpers on 2 3 4 7 8 9 counting from left to right with the radio positioned as above in my pics.


  9. stacey

    Thanks Ill give it a go! Thanks for your fast response!! will let you know the out come.

    • Mark

      Stacey’s radio is now fixed. It is critically important that a proper soldering iron is used, otherwise you can pull the pads off the board. On jumper 2, the connection to the processor is a via buried inside the pad and plated over, so you can’t even see it. At least, not until you’ve burned the pad off the board, at which point it’s a problem. Repair requires jumping a fine insulated wire over to pin 49 of the processor.

      Those of you contemplating surface mount/fine pitch work would be well served to invest in a Metcal temperature-controlled iron. They’re not all that expensive on the eBay used market, and they really are the right tool for the job. I’ve been in this business 40 years, and I’ve used a lot of different soldering irons. The Metcal is hands-down the best one out there for fine pitch work.

      • stacey

        Thanks again for the info Steve! And thank you Mark for your fine microscopic work! Radio was reset and flawless.

        • Steve

          No problem Stacey! I’m glad you found the info on this page useful! If you get a chance, would you mind letting us know what your final jumper configuration turned out to be? Thanks!


      • Steve

        Thanks for the info Mark! I was 2M certified back in the early 90s when surface mount was still kind of new. Worked with a Pace 3000 I think. You’re right though, you definitely need the right tool for the job.

        I happened to use the Radio Shack solder station like this one to do my mod and it worked out fine. Although it’s not the ideal solution for SMD work, I’ve used it a lot with good results. I used a lot of flux to help keep the heat flowing at a low temp and it worked on the first try.

        Thanks for getting Stacey straight, I’m sure he loves the access to the new frequencies!


  10. mark b

    hey guys, i wide banded my 857 a few weeks agao and have just come to notice there are quite a few of my menu items missing, the menu jumps from #49 up to #52 and has big chunks missing else where, is this due to the mod or is there another prob?


    • Steve

      Hey Mark, I haven’t seen or heard anything about that happening. Mine still goes from 001 to 091 but I have notice in the past that if I turn the select knob too fast it does appear to skip a few of the menu numbers.


  11. chemical

    I do not know if it’s just me or if perhaps everybody else experiencing issues with your website.
    It looks like some of the written text in your content are running off the screen. Can someone else please provide feedback and let me know if this is happening
    to them too? This may be a problem with my browser
    because I’ve had this happen before. Many thanks

  12. Steve

    I’m looking at it in Firefox and it looks fine. I haven’t heard anything from anybody else though.


  13. Peter Howard

    I have not fully read the thread. There is software that allows the 857/D to wideband. I have used it on my 857 version 1 and still do. If others want to know more I will dig into the archives to find it.
    Peter G0AFN

  14. Shawn

    Hello. My factory jumpers are exactly like yours. From left to right, 2,3 and I added 4,7,8,9. I used CircuitWriter, an currently waiting to dry. Just received radio today brand new. Serial number starts with 5F9703xx. Any idea if this mod matches the build number? Thanks

    • Sean

      Hey Shawn, did it dry yet? LOL. How did it go? does everything work as expected? I am getting ready to work on mine and am anxious to hear how things worked out for you.

    • ROD

      did 23 4789 work from Rod w3krq@

      • Rodney

        the mars mod is 23 6 789 then hold the vm and f func then power .up that is what I was doing wrong I was not holding the vm and func then powering up

  15. Tim

    I tried jumpers 6, 7, 8 & 9 with factory reset. Didn’t work. Bummer. 3k7304xx is my serial number

  16. Rodney

    I have tried 6 789 reset does not work My ser. no 5j010388 just got on feb 22 2016 so what is next

  17. Rodney


  18. Rodney

    Did someone find the new mars mod Rodney

  19. Rodney

    I gest no one has the new mars mod.

  20. Rodney

    i did the mars mod again the no.6 and 789 do the reset by holding in the vm and func botton then turn power on.

  21. jk

    FAILED – lost ARS, lost ability to do uhf/vhf

    US 857d, SER 5F970xxx

    radio looked like yours. tried adding jumper on 4 789 per you example.

    did reset. audio on 2m was weird. front panel “TON” and “RPT” buttons did not work. could run “split” mode, but, no way to turn on ctcss. Out of band worked, fwiw….

    reversed the mod. reset the radio. still TON/RPT no go.

    Loaded an 897 .img file I had from chirp, that fixed it, but, master reset will shove it back into a non-functioning state :/

    OK. Put mod back in, tried loading the 897 img, NO WORK because with the mod in it thinks it is a non us radio :/.

    repeated the above with 6789 with the same effects :/ I never tried removing the jumpers at 2 and 3.

    I am guessing removing 2 and 3, jumping 4 789 might work but that might go beyond my comfort level :/

  22. Steve

    Hi JK, this mod worked for me many years ago and may not work with yours. All I can say is be careful while poking around in there with a soldering iron. I’m not sure how you would have gotten “weird” audio as I’ve not heard of that happening before.

    I’ve also never used Chirp with my 857 as everything I read stated it would basically brick the 857D’s and it would only work for the original 857’s.

    I did the mod just like I referenced in the discussion board at WWDX and it worked for me the first time.

    I do know the Master Reset process can be tricky as well so make sure you are doing that correctly when you make your changes. Good Luck!


  23. ken kennell

    Looking front to back let’s call them 1 to 9, my radio had jumpers at 2, 3 and 4, I removed all but #4 which controls aspects of memory storage, installed jumpers at 9, 8, and 7, did reset by holding v/m and f buttons while powering up to reset to defaults and now I transmit and receive all bands and all modes, so from front to back it should be #1 open, #2 open, #3 open, #4 JUMPER, #5 open, #6 open, # 7 JUMPER, #8 JUMPER, #9 JUMPER, good luck, wear a static strap and always ground your equipment and yourself when the covers are off and you tinker inside, 73s all. Ken

    • Kage

      Was wondering if you have noticed any side effects from removing jumper 2 and 3 like listed in the comments about the processor circuit not operating?

      • Steve

        Hi Kage, I did this mod a few years ago and I haven’t noticed any side effects but if you’re referring to 2 and 3 counting from the left in my pictures, I left them in there for mine. From what it sounds like, if you pull them off and the radio doesn’t work, you can put them back and it should be fine. Just do the master reset when you’re done to make sure it is going to work or not.

  24. Steve

    I just bought up my 857d from a QRP guy. SN# 4J31xxxx.

    Dose anyone have a list of serial numbers for the 857d for the mods that can be done to it or what mods work?

    I use mine in my 4×4 and several others do not have ham bands, so I talk to them on the CB freqs. What is the mod for the 857d that will allow it to TX in the CB band?

  25. Humberto

    Hi!, i’m write from Argentina and need to know if is possible make the modification to reach 174 on 144/430 band. now I’ve FM to 137 to 164 MHZ.
    On label: DST; EXP, TYP: B3, VOL:DC, PWR:100.
    Thanks in advance.

  26. Yaesu whisperer

    I just got an FT-857D this summer in Japan. The TX band edges in VHF/UHF are 144-146/430-440 and am trying to find out which jumpers to use for the US band edges (144-148/430-450).
    Label on side of box says DST: JPN and TYP: FH.
    Jumper pattern on the board is: 1,2,7.
    With 7 removed (ie, jumpers 1 and 2 as per US radios), there appears to be no change to the Xmit band eges. When all jumpers but 6,7,8,9 are removed, as per MARS mod mentioned about, the radio will only tune into 144-146 and 430-440 (ie, all other bands disappear even in receive).
    Returning abck to 1,2,7 returns to normal Japanese 857D coverage.
    Anyone else have experience with these?

    • John

      Yes, JDM radios CAN NOT be modded. The eeprom programmed that way

  27. Luiz Ricardo V Alves

    I have Yaesu 857 SN 5C370212.
    What procedure to unlock the band 118-136Mhz? TX and RX….
    Thank you!

    • Bruno Schagas

      This is forbidden are you a pilot or air traffic controller,easier to buy an aviation radio Icom IC-5,IC-6 or IC-A110 or A120 It would be interesting to release the FT but it is via software and physical system modification and nobody will do that on the network this type of information.

  28. Bruno Schagas

    Hello good night,is possible make the modification to reach Tx 136Mhz-175Mhz in FT-857D.
    Thanks 73.
    Best regard,
    PU1XWZ Brazil.

  29. Morgan

    I bought a used FT-857d a few years back, I finally got around to freebanding it and after various combinations recommended on this board, 4 789 ultimately would up being the combination that worked for me. This opened up MARS/GMRS frequencies while retaining repeater offsets/pl codes.

  30. Greg

    I have a 857D. Would like to open HF while not affecting 144/440. Any one have jumper config for that. Radio 4 or 5 years old.

  31. Mike

    Hello and thanks for the info. Wanting to do this for my 857D Serial starting with 7E17xxxx, Does anyone have the right pin configuration for this radio and what is the best way to bridge it? Thanks in advance.


  32. Rfrank

    I have 7E17XXXX same as you Mike. What have you found out? If you did it, is it working?

    • Mike

      Sorry nothing yet, Not sure if anyone else has done it. Just checking the site again as I am trying to open up the radio before Irma makes landfall…

  33. Andy

    This worked perfectly for me with no problems. New radio as of 9/2017, S/N 7F2000XX. I used a CircuitWriter and a paper clip.

    It would not restore my backup in the Yaesu software but I was able to read from the radio and copy/paste my freq. list to the new file and write it back to the radio..

    • Steve

      Thanks for the report Andy! I think after doing this mod, the radio thinks it is from another region that that’s probably why your software was seeing a different radio. Either way, I’m glad it worked out for ya!



    • Mike

      Andy, which pins did you jump? Thanks in advance.

  34. Richard W0QGS

    Anyone have any idea what jumpers to do for the 857D with serial #: 6N160XXX?

  35. Joe

    Hi ,after a lot of reading and opening the radio 3 or 4 times just to convince my self that the jumpers where not that small ,i decided to try the mod.After a little bit of practice on scrap circuit board i was feeling confident enough! So North America radio sn#6n16xxxx removed the 1 and 2 jumpers and solder 6 789 white numberd on the board (odd) little reset …so far working good exept the auto rep shift and the 60m are no more .But still you can put back the 60m frequency on the memory ,the repeater shift need to be set manualy.

    73’s from

  36. Neil Cahill

    is this mod safe for the radio? is there any risk that operating rx/tx in the “new” frequencies can damage anything? i like the ability to use this radio in such a wide range …. anyone have any experience with it? I bought a galaxy dx 959 to do my cb things with, as the the yay-sue is too good to beat up as a cb, but it works fine. and is great on frs gmrs and murs locally…

    • Robby J

      Ive got a IC706mk11g n its fully open,but as to your question.mine is perfect ONLY be sure your antenna awr is good on your chosen tx freq.other than that mine has lasted 12 years opened. Yaesu are EQUALLY Top quality I cant see any issues UNLESS others ould comment..Good Luck,Good DX.. Robby

  37. Robby J

    Can I unlock it with software from Yaesu ??? mine is a 2017 model year bought.BUT I don’t know how many years on their shelf

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