my main interest is being able to listen down into the MW broadcast band a bit more cleanly and also having the TX unlock for MARS use — i do some emcomm stuff so that part actually has practical value for me. the rx thing is more just curiosity honestly.

i found a couple different procedures online and they conflict on which jumpers to move, which is making me nervous. the board in the ND version is different from the original apparently? mine is an ND so i want to make sure im not bridging the wrong pads and bricking something. anyone done this recently on an ND unit specifically?

the audio mod is what im most curious about getting feedback on. i pulled the internal speaker and replaced it with a small aftermarket one, added a tiny bit of capacitance to smooth out the low end. it actually sounds warmer now? hard to describe but received audio is less tinny. not sure if thats placebo or real but my ears say its better.

has anyone else gone down this rabbit hole with the 7300 or any other radio. wondering if theres mods i havent thought of yet, particularly around the PA section or the front end for better dynamic range on crowded bands.

anyway the procedure itself isnt bad at all, the diode is surface mount so i was a little nervous but with decent iron and flux it came off clean. i also did the 1200hz shift mod for the internal keyer while i was in there because why not. the thing that surprised me is the radio actually feels a little more responsive on receive after all this, which makes zero sense and is probably just placebo, but whatever it feels better.

the only thing i messed with that i wish i hadnt is i tried to adjust the SSB TX bandwidth following some guide online and i think i made it slightly worse actually. not terrible but not quite right. might go back in and reset that to factory. anyone else done the audio bandwidth tweaks on this rig and had better luck?

the mod itself isnt too bad if youre comfortable with fine pitch SMD work, theres a pads on the main board where the TCXO drops in and you pull a couple resistors. took me maybe 45 minutes with a good iron and a steady hand. used the Hy-Time part that a few people on the SDR forum were recommending. stability went from maybe plus or minus a couple hundred millihertz of drift over a few hours down to basically nothing i can measure. the reference stays rock solid now even when the temp in here swings 10 degrees.

anyway if anyones been on the fence about doing this i say go for it, just dont rush the SMD part. only thing i wish i knew beforehand is that you should recalibrate the radio after the install, took me a minute to figure out why my displayed frequency was suddenly a few hz off before i remembered id need to reset the ref.

install itself wasnt too bad if you've done any SMD work before, main thing is not rushing the reflow on those tiny pads. took me maybe 45 minutes including the time i spent second-guessing myself and looking at the service manual like three times. anyway the difference is actually noticeable — fired it up this morning at about 55 degrees in the shack and it came up rock solid where before id see it wander maybe 50-60hz before settling. wsjtx is a lot happier now.

curious if anyone else has done any other mods on the 817 that are actually worth the time, not just the usual "mod it for mars" nonsense. i've seen some stuff about the PA transistor swap for slightly more output but not sure its worth the risk on a radio this old

anyway it works, i can now TX outside the ham bands which was mainly the point because i do some MARS stuff with my local group and the workaround we had before was kind of a pain. audio sounds the same to me on HF, havent noticed any difference in receive either. one thing i wasnt expecting is it seems like the ALC behavior changed slightly on 10m but that could just be me imagining things, hard to say.

anybody else done this and noticed anything weird after? also thinking about doing the internal speaker mod at some point because that stock speaker is genuinely awful. or just live with it and use headphones i guess

anyway i finally pulled the trigger on the TCXO-19 upgrade last month. the install itself was pretty straightforward, just the one board swap, took me maybe 45 minutes including double checking everything before i closed it back up. honestly the hardest part was just not stripping the tiny screws on the board.

and yeah the stability difference is real. like genuinely noticeable right from cold power on. i was skeptical it would matter that much but the 7300 with the stock oscillator is just not as tight as i expected from a radio in that price range. now it sits rock solid from the moment i key up. FT8 is way more satisfying, no more babysitting the AFC offset at startup.

curious if anyone else has done this mod and what else they found worth doing on this radio. ive heard some people do the fan mod to run cooler on digital but im not sure if thats actually necessary or just overkill for normal use.

the mod itself wasnt that bad, had to pull the top cover and there's a few SMD components near the RF board that you swap out, nothing crazy if you're comfortable with a soldering iron and have decent magnification. i used my hakko with a fine tip and took my time. whole thing maybe took 90 minutes including the disassembly.

honestly the difference on 160m and 80m is noticeable, weak signals that were getting kinda chewed up by the AGC are cleaner now. 40m feels about the same to me. i dont think i'd say it transformed the radio or anything but for the time invested it was worth doing. just wondering if anyone else has gone further with mods on this radio, i keep seeing references to some IF filter mod but cant find good documentation on it

my question is whether anyone has actually done this on a 7300 specifically. i know the mod exists for a bunch of rigs but ive seen a few posts saying the 7300's front end gets kinda overloaded on the broadcast band anyway so maybe theres not much point. also wondering if it affects the warranty situation — mine is still under the extended warranty i bought from the dealer so im a little gun shy about cracking the case open.

if you have done it, how hard is the disassembly? the board access looks pretty involved from the photos ive seen, not sure i want to get into that rabbit hole right now but just trying to figure out if its worth the trouble.

my question is has anyone actually done both mods on the same radio and if so was the improvement noticeable enough to justify cracking the case open. im reasonably comfortable with a soldering iron, done some work on older tube gear so small SMD stuff doesnt terrify me but i also dont want to mess with something thats been working reliably for years if the gain isnt worth it. the collins filter in particular seems like it could make a real difference for CW but i mostly do SSB and some digital so maybe its not even the right mod for my use case.

also if anyone has the specific cap values handy for the audio board replacement that would be helpful, ive seen different numbers floating around on different sites and im not sure which version of the board mine has

results are... honestly mixed? i'm definitely hearing more on 10 and 12 meters but i also feel like the noise floor came up a tiny bit on 40 which is where i do most of my work. could be my imagination or could be i just stirred something else up when i had the thing open. solder work looked fine when i put it back together, no cold joints that i could see.

anybody else done front end work on the 7300 or similar radios? wondering if the tradeoff is worth it or if i should have just left well enough alone. also curious if theres a recalibration you're supposed to do after, the write-up i followed didnt mention anything but im second guessing myself now.]]>2743Mon, 29 Jun 2026 16:39:39 +0000https://www.hamradiobase.com/forums/topic/914-modded-my-ic7300-front-end-and-now-im-wondering-if-i-went-too-far/so ive been running my 7300 for about two years now and generally happy with it but i kept reading about the front end being a little soft on 40m especially when the band is crowded, so i went ahead and added an outboard preselector — not really a mod inside the radio itself just a bandpass filter setup i built from a design i found on qrz. that part went fine actually.

but then i got a little ambitious and started looking at the LNA mod some guys do where you swap out the input section stuff to improve dynamic range. i found a writeup on a japanese site (translated it with google which was... interesting) and went in with a soldering iron. the work looks clean under magnification but now im noticing the noise floor seems slightly higher on 80m than before and im not sure if thats real or if im just paranoid because i touched something i shouldnt have.

anyone done similar mods to theirs and have baseline numbers to compare against? i dont have an SDR to run proper measurements and im mostly going by ear which i know is not ideal. radio otherwise works fine, all bands, no weird spurs that i can hear.

anyway the actual mod took maybe 20 minutes once i had everything laid out and a decent light on the board. the tiny SMD diodes are a pain but doable with steady hands and a fine tip iron. what i wasnt expecting was how much better the fan mod helped at the same time — ran a 12v fan mod off the same session since the board was already out, and that thing used to get pretty warm running digital modes for any stretch of time.

my question is really for anyone who's gone further with this radio — i've seen people talking about the ref osc mod for better frequency stability and i'm kinda tempted. does it actually make a noticeable difference on like, normal SSB and FT8 use or is it more of a contest/weak signal thing? feels like the stock osc is already pretty decent but i dunno, maybe im just not noticing drift because im not doing anything that demanding.

what i actually ended up doing was the front end mod where you bypass part of the stock input filtering and add a low noise preamp stage. took me a weekend and honestly the difference on 40m in the evening is noticeable. the noise floor dropped maybe 3-4 dB by my measurement, might be confirmation bias but i dont think so. also reflashed the firmware to an older version someone recommended because apparently the newer ones have some AGC behavior that people dont love.

anyone else been messing with the 7300 hardware or is everyone just leaving them stock and using the DSP? curious what actual improvements people have gotten vs just tweaking software settings

also saw something about a different crystal oscillator swap but that one looks way more involved

anyway the reason i actually got around to it is i wanted to experiment with some of the 60m channels and also just generally wanted more flexibility without having to think about it. transmit works fine across the extended range, power output seems consistent, no weird behavior on the bands i normally use. i did notice the fan seems to kick on a little earlier now but that might just be me paying more attention to it after poking around inside the radio.

what i really want to do next is the high stability TCXO option but those seem hard to source now. anyone done the TCXO-9 upgrade recently and know if theres still a reliable place to get one? my understanding is it drops the frequency stability from like 5ppm down to 0.5ppm which would actually matter for weak signal stuff on 2m. also been reading about people doing filter swaps on the 857 for better SSB audio but im not sure if thats worth the hassle on a radio this size

the mod itself is pretty straightforward once you find the right diode matrix — theres a lot of conflicting info online about which pads to bridge depending on the firmware version so just make sure youre looking at the right diagram for your specific unit. mine is an older one so the pad layout matched the older docs. took maybe 20 minutes total including pulling the bottom cover off.

extended rx is working great now, been listening around on some frequencies i couldnt touch before. the transmit unlock i honestly probably wont use but it was part of the same mod so whatever. what i actually want to do next is look into improving the audio on rx, the stock filtering always felt a little mushy to me especially on crowded ssb. anyone done anything with the IF filtering on these? i know you can drop in a Collins mechanical filter but im not sure if thats actually worth the cost vs just using DSP filtering in the radio or an external audio filter downstream.

first off the jumper pads on mine were already partially done from the previous owner, which i didnt realize until i was already in there with a soldering iron and wondering why the layout didnt match the diagram i had printed out. so if you're buying used, worth checking before you assume its stock. second thing is the alignment after — i had a slight power drop on 10m that i thought was a problem but after letting it warm up for a half hour it came back to normal, probably just needed to stabilize. overall TX is clean across the expanded range, checked it with a spectrum analyzer my buddy has and no obvious spurious junk showing up.

also while i was in there i replaced the finals cooling pad because the old one looked dried out and gross. not sure if that was strictly necessary but seemed smart. anyone else done the port expansion mod on these? been thinking about the CI-V speed fix too but not sure if its worth the hassle for how i use it.

after that i went down a bit of a rabbit hole honestly. did the internal fan mod where you swap the stock fan for a quieter noctua-style unit and rewire it to run at lower voltage most of the time. runs so much cooler temp-wise in the shack now and i dont have to turn up the monitor speakers every time i key up. also did the barefoot audio mod that's been floating around the groups.io for a while, just a couple resistors on the TX audio path and it really does open up the transmitted audio a bit, my buddy in michigan said i sounded noticeably better before i even told him i changed anything.

anyone else gone down this road with their 7300 or other radios? curious what mods people actually found worthwhile vs the ones that were more hype than anything

while i had it open i also trimmed the ref osc since mine was running about 150hz high on 10m which was bugging me for a while. used a GPSDO as my reference and got it dialed in real close, like within 10hz now across most of the HF bands. way better than it was.

anyway the whole thing took maybe two hours including the time i spent staring at the service manual trying to figure out which jumper was which. if anyone else has been on the fence about doing this it really isnt that bad as long as you have a decent set of JIS screwdrivers. regular philips will chew up those screws fast.

thinking about also doing the collins filter mod next but not sure its worth it on this radio vs just saving up for something with better DSP. anyone done that one?

what i mainly wanted it for was listening down in the MW broadcast band and also some utility stuff around 400-500 MHz range. the sensitivity in the extended portions isnt gonna win any awards obviously since the front end filtering isnt there, but for casual monitoring its totally usable. i did notice a slight improvement in overall feel after doing a realignment but that might have been placebo, hard to say.

anyway anyone else done this or any other mods to their 7300? i've been thinking about the TX unlock mod too but im a little nervous about that one from a legal standpoint depending on how it gets used. also heard some people are swapping out the stock fan for a quieter one, curious if that actually makes a difference on the heat management side or if its just for noise reduction.

the difference on 40m during the evening hours is actually noticeable, like strong broadcast stations that used to bleed in a little are just gone now. i was skeptical honestly because i thought it might be one of those mods where you talk yourself into hearing a difference. but comparing recordings before and after with the same strong local signal nearby, yeah the noise floor behavior is cleaner. hard to explain but the AGC seems to react less aggressively now.

only thing is i had to reflow a couple of joints because my soldering iron tip was getting old and i wasnt confident about two of the pads. took me longer than it should have. anyone else done this one or something similar on the 7300? curious if people went further and did the band pass filter work too

for anyone who hasnt done it, its pretty straightforward once you get the thing open — theres a diode on the main board you either remove or short depending on what you want to do, the Yaesu service manual has the details. took me maybe 45 minutes including the time i spent second guessing myself and looking at the board with a flashlight trying to figure out which one was D4003 or whatever it was.

anyway the reason i did it wasnt just for extended TX, i mainly wanted to mess with the receive on some of the utility stuff below the ham bands. and honestly its working great for that. also been thinking about doing the internal fan mod because this thing runs hot when im doing digital modes for more than like 20 minutes. anyone done the fan upgrade on one of these? ive seen a few writeups but theyre pretty old at this point and im not sure if the links to the replacement fans are still valid.

the rx improvement is honestly noticeable on 160m and 80m where i was struggling before especially with all the local noise here. the noise floor came down maybe 3-4 dB which doesnt sound like a lot but on a crowded contest weekend its the difference between pulling a call out of the mud or not. the TX mod i havent really used much, just nice to know its there.

anyone else gone down this rabbit hole with the 7300 or other rigs? im thinking about doing the speaker mod next, the internal speaker on this thing is genuinely awful and im reading about people swapping in a better driver. curious if thats actually worth the hassle of opening it up again.

the main reason i wanted it was for some MARS/CAP work our group does occasionally and also just wanted the flexibility when doing testing on adjacent freqs. not planning to transmit outside the ham bands obviously, just nice to have the option without the rig throwing a fit.

anyway the mod works fine, rig is still performing exactly the same on the ham bands as far as i can tell — same ALC behavior, no weirdness on the spectrum display. i dont have a great way to do a proper before/after power output comparison outside the ham bands but on 10m and 40m it still hits the same numbers it always did.

anyone else done this on the 7300 specifically? im curious if anyone noticed any difference in rx performance or anything unexpected after doing it. also if theres other mods people think are actually useful for this radio id be curious what people have tried.