Yaesu FT-991 Frequency Expansion MARS / CAP modification

[@rickmaudlin2160]

Thanks Brett for a great and instructive video as usual, and for taking the time to provide this information.

[@survivalcomms]

You are welcome ! Thanks for watching !

[@SteveH-TN]

Appreciate you sharing this video , as MARS/ CAP member, just ordered a FT-991a de AA4SH

[@survivalcomms]

Thanks for watching !

[@ChristisKing7749]

I took a 991a apart to solder in a new clarifier knob. I undid that big ribbon cable and plugged it back in after much struggle. It was unbelieveably difficult. The radio would not power up anymore. I sent it back to Yaesu for repair. So yeah leave the big ribbon cable alone. Clarifier knob repair was successful :)

[@survivalcomms]

Some ribbon cables are worse than others as you found out. Glad you got it up and running . Thanks for watching !

[@izzzzzz6]

Thanks Brett. I just wanted to check the work of the previous owner while cleaning and tightening all of the grounding points. I noticed some of the copper ground springy tabs are not well aligned, I also polished up the surfaces they contact. I checked all board screws to ground too. I had the radio in pieces to replace D113 as it was leaky and stopping the PA port aux ppt switch to ground at the rear of the radio from functioning. If anyone has to replace D113 then let me say it's not for beginners. I got it in without any trouble but it's one of the smallest components I've had to work with with some limited access.

[@survivalcomms]

You are welcome ! I have an IC7300 here that had the the current sensing voltage regulator burn up after a lightning strike. I got everything out and have the parts but you are right everything is so tiny. Thanks for watching !

[@mechpilot5861]

Works like a charm!

[@survivalcomms]

Cool beans ! Thanks for watching !

[@mechpilot5861]

Just got my FT-991a today, made this mod in 5 minutes, and everything is perfectly working now! Only need to do SWR adjustment to the new antenna.. :D Good to be electronics designer, so easy mod to do!

[@survivalcomms]

@@mechpilot5861 Yes the hardest part is taking the screws out :)

[@mechpilot5861]

@@survivalcomms So true :D

[@remarkable_ruin8608]

Anyone know how to extend the uhf range?

[@bigchew3149]

I Really want/Need to know how to mars mod the VHF/UHF n my 991

[@survivalcomms]

Unfortunately it isnt going to happen from my research. If you find out how to do so please let me know. Thanks for watching !

[@NickFrom1228]

Your camera was a tad out of focus when doing the jumper. But otherwise sufficient. I have a 991A that I plan to do this to. Thanks.

[@survivalcomms]

Thanks for watching !

[@Pacman163]

My mod was working till I just did a firmware update and now it won't work not even after holding fast and lock while powering on. I think the June 3-2024 firmware did something

[@CliffFoxKU4GW]

Will the ATU operate on any of the expanded transmit frequencies, like on 60 meter frequencies? "Very 73 de KU4GW, Cliff"

[@survivalcomms]

It will however the tuner in this unit is pretty limited. Thanks for watching !

[@dartor646]

so if I wanted to hit a gmrs repeater the mars mod wouldn't do the trick?

[@survivalcomms]

No there are NO mods for this radio that put it in GMRS range. Thanks for watching

[@itchybluffs2714]

So what frequencies does the mars mod unlock on the FT991A?

[@survivalcomms]

The HF bands. VHF / UHF mods for this radio do not exist. It is all in the video. Thanks for watching !

[@MikeSmith-s9n]

Is there no mod for the VHF/UHF bands ?

[@survivalcomms]

Not that I have found. If you find one let me know. Thanks for watching !

[@DBCoopersGiblits]

Not a permanent mod, however tuning to the frequency you wish to TX and setting up your power and all your settings, you can turn the unit off - press and hold A=B A/B and FAST while turning the unit on. DO NOT use the Clarifying knob while in this mode as you will change how the radio operator internally. Now that you are in this system configuration mode, make sure your in setting 1, smash the band switch button until you find the band you tuned up. Viola your TX unlocked. Unfortunately you have to do this every time you change frequencies. PS make sure you turn it off before messing with any knobs. No known permanent mod as of yet. 73

[@survivalcomms]

@@DBCoopersGiblits I have seen that done but never tried it personally. I sold this radio soon after I made this video so I don't have the chance to test it myself. I know from experience on other radios however that one has to be very careful in these hidden menus. Its easy to misalign a radio in a service menu. Thank you for sharing and thank you for watching !

[@amlo2266]

​@@DBCoopersGiblitsI thought it was up down up down left right left right THEN a b a b start?

[@dirtysquatch7036]

Does this mod open up tx on 11 meter?

[@survivalcomms]

It does. Thanks for watching !

[@dirtysquatch7036]

Its hard to tell but it looks like your pointing at the first jumper on the bottom?

[@newsmickey5272]

The jumper that's way out of focus, right LOL 😜

[@survivalcomms]

Thanks for watching !

[@Aerospacejack]

Wow, hard to see with the camera focus.

[@survivalcomms]

Thanks for watching !

[@hypnosiscenternyc]

Will a base 991a transmit on a gmrs repeater frequency? Thanks

[@survivalcomms]

No Thanks for watching !

[@freddysamson1]

I want the vhf and uhf mod if you know of one help please.

[@survivalcomms]

There isn't one. Thanks for watching !

[@paulkazjack]

I reckon those other jumpers are worth soldering. This may onlock vhf and UHF frequencies. Worth a try.

[@survivalcomms]

I'm confident someone has tried that before and found it just changed it to a Japan config etc. I sold the radio soon after making this video. Performance of these multiband HF rigs out of band more than a few mhz on VHF / UHF has been pretty poor in my experience. An el cheapo FM rig out of the box however pretty much only suffers at the extreme band edges if at all. Thanks for watching !

[@ChatGPT1111]

So what happened when you did that?

[@socalfishing3121]

I was really thinking about getting into ham radio but after listening to the 40 meter band at my friends house and how rude everyone was on that band I don't think I am going to take the general test anymore I mean come on man just a bunch of men carrying on and on about nothing and wont let any one else break in or talk guess not

[@survivalcomms]

I understand the sentiment. I would tell you not to let a bad experience make up your mind for you. The access to spectrum is worth it in my opinion. Thanks for watching !

[@blueline308]

Shame you didn't take 5 seconds and focus the camera.

[@survivalcomms]

Thanks for watching !

[@reinersteinweger3874]

Das so ein Geheimnisse gemacht wird wegen der UKW Modifikation ...kenne viele Om's die diese Marke nicht mehr kaufen....

[@survivalcomms]

Ich habe es vor einiger Zeit verkauft. Ich mochte das Radio nicht. Ich habe kommerzielle Funkgeräte, die ich im LMR-Spektrum verwenden kann. Danke fürs Zuschauen!