#90 ICOM IC-7100 ALC modification to get full TX power on SSB

[@jgeorge6081]

I just performed this mod on my icom 7100. It works quite well and the signal quality reports were good in the qso after I finished the changes. I was aware of this before, but I was hesitant to do it until I saw that this individual, who's technical skills I respect, showed that he had implemented it and, importantly, showed the justification for why it works. This gentleman posts superb videos. Anyone who gives him a thumbs down is just bent.

[@TRXLab]

Thanks for the kind words! 73

[@JosephMassimino]

I called Icom repair in Michigan and spoke to them about what Icom told them to do if anyone complains about low audio on the IC-7100. I was told to upgrade the firmware. I am happy to say that once I did the last three upgrades, my SSB audio was corrected to read near 100 watts on Hello, Audio, Hello Audio. No yelling involved, and MIC set at 65%. Comp on yielded the highest reading, Comp off was slightly less.

[@TRXLab]

Hi Joseph, very good that it works with the new firmware in your case. Upgrade first is what I always recommend . Thanks for comment 73

[@martinborman4195]

Okay.

[@JerryNSretired]

While I would not doubt the success of this mod, I would, however, be wary of overstressing *other* components. A few years ago, people were modding Kenwood TS-50s and bragging about 150 watts output. Then *POP*!! There went the finals! I would err on the side of caution...and take YOUR approach!:)

[@beekeeper8474]

Didn't work on my radio

[@davemitchell116]

ICOM has corrected this issue. The IC-7100 I bought 4 weeks ago has full SSB output. It was one of the first things I tested.

[@andrejstefanovski]

Dave, thank you for posting this. I was considering a purchase and I am happy to hear this has been corrected in manufacturing.

[@вечная_мерзлота]

@@andrejstefanovski I bought one 3 month ago and it's transmitting stated watt. what a rig I tell ya!

[@tomch4467]

How can you tell if the one I purchased two years ago has been corrected

[@akeem11h]

@@tomch4467 look at your power meter on radio to see if it swing's to 100 watt

[@akeem11h]

@@tomch4467 The stock mic is not the best, I rearranged the wires if HM-219 to match the ic-7100 pins, radio works at 100 watts. Check your SWR to get full power, icom recommends 1.5:1. Have fun.

[@javaman3765]

Hello Peter, One tech to another, Your modification does work indeed, overly so. 2uf to 3uf is far to much capacitance on that ALC voltage rail. What all of these videos do not comment on is that you loose total control of the power level control. As soon as you adjust power output past 15-20 watts setting the radio is hammering 120-130 watts in that essentially there is little to no ALC action with that much capacitance. Not to mention a monster axial cap is ugly against that beautiful SMT board. Next time you make this mod might I suggest using a .1uf (yes, point one (.1uf) ceramic 0805 cap tied in the same fashion from that ALC rail to ground. You will see the same ALC improvement, retain same linear control of the power output control function. And, yes your right, do not add that short wire....just the .1uf ceramic non polarized cap. Nice and clean.

[@FrankW650]

Hi, do you realy think or tested that a 0.1µF capacitor over the R1522 is enough? I understand you tell no bridge over transistor Q1504, isn´t it? I did bridge it and I can not reduce power any more for example 10W without big peaks. That´s not good because my LD-MOS PA needs only 20W for full power output. Overshot is forbidden. 73 de Frank, DL2GRF

[@kp4ia]

Hi Peter, greetings from Puerto Rico. Purchased my IC-7100 back on Dec 2016, the firmware update did not fix the RF out issue in HF SSB, I had been watching you videos, very informative & educative. Excelent video. Because of the low power in HF SSB I decided to perform very carefully the modification in my IC-7100 and the radio is working fine. Thank you for spreading the modification procedure ! 73's Tony-KP4IA

[@TRXLab]

Thanks for your feed-back! It is good to have here different results collected as it gives a full picture. So again thank you. All the best and 73

[@lwhited1]

Nice video. I used to have this problem. Just checked it on my peak ready watt meter and I am getting an easy 100 watts with 52 percent MIC gain. Seems the E5 firmware fixed it for me. Glad I don't have to solder! Thanks for the interesting video

[@TRXLab]

Hi Laurence, thanks for the feed-back. Very good that it worked with the new firmware for you! 73

[@ohmmeters]

I made the 2 modifications and are now happy to have a really clear and undistorted SSB-modulation that really draws the attention on shortwave even if I hold the mike (HM-198) 40 cm from my mouth. and it can easily be calmed down by shutting off the compressor/reducing the mike-gain. Thank You again TRXBench!

[@TRXLab]

Hi Lars, I'm glad that the modification turned out that good for you! Thanks for watching 73

[@JosephMassimino]

So we have to consider that the Icom engineers knew about this, and they reduced the output power to correct a separate issue. If that was the case, the real issue might be that the increased power causes some other failure that Icom would be responsible for fixing on their dime. Only time will tell. So if somone makes this mod, and they give the radio a good SSB workout, if that causes a failure in some other related circuit, it would benefit all IC7100 owners to hear about it. I am not a heavy SSB user, and my main radio for SSB is the IC7600, my IC7100 was left for Dstar use only. Although, I have to say that Dstar on HF has been less than good on the IC7100, where SSB on HF using the IC7600 has been great on the same antenna. This MOD seams easy enough to make, but you have to wonder how it got past quality control at Icom. The only honest mistake could be if the original IC7100 had other parts, and at some point the quality of those parts had changed. The only way we could know that is if we hear from some of the first IC7100 owners and see if they had this same problem. The IC7100 has been out for a while, so a change in parts could be the cause of this RF problem. This is my opinion, so please don't flame me for it. Joe KQ4BX

[@matsbladh6359]

+Joseph Massimino Other persons opinions are always welcome! I don't think that 7100 is having a weak Power stage that could burn if transmitting with normal levels on SSB. Maximum power output on other modes are really good on my 7100 and I can transmit for extended periods of time without detecting any unnormal sweating. I guess that Icom in some stage when designing the rig did not really consider the importance of finally testing the rig in real use before pushing the start button in the factory line. And the reason for this ALC-flaw can be as You said component(s) changing quality.. I am a real novice but as You I also try to understand how Icom could release a rig with this kind of serious flaw. When remembering the IC-2820 and it's low quality modulation that went really bad when Icom suddenly decided to ship the rig with the cheap China manufactured microphone, it looks like Icom don't care much about testing anything at all when changing the original setup.

[@TRXLab]

+Joseph Massimino Hi Joseph, I agree with Mats comment! Thanks for watching 73

[@TRXLab]

+Mats Bladh I fully agreed! Thanks 73

[@kd4nqy]

In my past experience i have increase the power in 4 radios to 200 watts ///kenwwod ts-50 // ts-930 and ts -940 ,,, and ft 1000...and never have any problem with them until i sold them...but i was heavy criticize for doing this,and almost all of this guys says that i will fry my radio in no time...that never happens...i am glad that he post this video,if i ever purchase this radio i will do this modification for sure,i take the risk...i need those 100 watts baldly no Mather what...but i also agree with your comment ,is very true,i respect your point of view//////,after this mod is performed only time will tell...73

[@fey4949]

Hello Peter, the wright questions have been asked and answerd about modulation and IMD and if the PA is happy we are happy. Very nice mod, good explanation. I think you saved a lot of radio's for selling. Take care until next time. Henk

[@TRXLab]

+FEY Hi Henk, thanks for feed-back 73

[@mikesradiorepair]

Excellent job Peter. Always fun trying to fit through hole components on a SMD board. They really did goof on this radios ALC circuit. Glad you came up with a fix for it. Mike

[@TRXLab]

+MikesRadioRepair Hi Mike, yes through hole and smd is always fun :-). But in this situation no smd part would fit that's the problem.. Yeah fix works great. Thanks for stopping by 73

[@StefanManjakov]

I don't like making ALC slower to react. In this case its better to lower the ALC gain. I have 7100 and using it mostly on CW and digital modes.

[@zooyawk4526]

Another excellent mod/repair. It amazes me that Icom (or any high tech company) would allow equipment to be built with an inherent problem like this. People pay hard earned money to own a piece of equipment that should work for years without an issue. Especially an issue that doesn't have to due with age and or, wear and tear from everyday use. More testing before release of equipment would solve unnecessary failure. Manufacturer should catch poor design before the item is released for sale. Excellently produced video as always.

[@TRXLab]

+4Q2 42Q Hi, yes I agree it is really a shame... Thanks for comment! 73

[@robertcalkjr.8325]

Thanks Peter. That "fly shit" was funny. It is also accurate. lol Those things are so tiny nowadays.

[@TRXLab]

+Robert Calk Jr. LOL yeah it is also accurate.. Thanks for watching Robert 73

[@DJCaverna]

OMG ... this is a salvation for this great RIG .. i sell my new one 7100 because he has low modulation deflection ... tanks a lot

[@TRXLab]

+DJ Caverna Haroldo Bradaschia Neto Hi Neto, thanks for feed-back now you can buy your rick back :^) Thanks for watching 73

[@radioshopbob]

You always do a great job on these videos Peter. Thanks for doing these for us..

[@PoppaCrowe]

WOW, A you tube video I actually enjoyed ! Reminds me so much of when the guys from Europe would come over and do training with us on the Xray units. Thanks for the video, and your time !

[@TRXLab]

Thank you. Did you work for an European company??

[@greenrefrigerator]

Why would the manufacturer design the radio this way?

[@markginsel4238]

I'm confused as well. Just speaking into the mic to try and determine SSB performance doesn't work, it requires a 2 tone continuous signal. Plus I can't help but wonder what does the received audio sound like after the mod?

[@k2icc]

Maybe compliance and alignments at lab to avoid RFI or some spurious emissions. Now with better home technologies, CB-ers get away with high power amps. Some IC-7300 for example has 25 watts in AM while the IC-7100 has 30 watts, some state 40 watts?

[@greenrefrigerator]

@@k2icc That still doesn't answer the question of why a radio manufacturer who markets and sells a transceiver touted to have 100 watts RF output can't do what it's advertised to do without modification. Nearly all 100-watt transceiver put out at least ONE-HUNDRED WATTS (or better), yet this model falls short. Just makes no sense why that is.

[@k2icc]

@@greenrefrigerator Unless people like you and me bring those things up, no one will listen to it or will care, to be honest. There is a lot going on. In plain words, a certain percent of power at a certain mode, could be considered legally what they state. For example, my internet provider sells me up to 400 Mbps. So, I don't get 400 Mbps, but close to 380, and still legally stated. So, they could state, due to some kind of whatever spurious or this or that, the reason for the values. This guy on the test knows what he is doing, so he can do what most can not do, as the equipment needed to prove the radio has certain amount of power, and that on a new radio can void the warranty, etc.

[@jeffschall2062]

Pete I bought my 7100 a few months ago and it has the latest firmware in it from the factory, it's all up to date and the only way I can get up to 100 watts is to use the compressor, so after your mod the jumper and the cap I got full power plus some extra. With the compressor off I turn it down to 100 watts peak and it plays fine, it also drives my als 500 better without sounding over modulated, thanks for the mod and I love your videos, 73 kc8hxr/6

[@TRXLab]

Ahh very good glad that the mod was helpful to you and thanks for your report! 73

[@Skruffify]

Did the mod to my 7100, had VE6JF do the work for me (Briillant Guy), went from 17w peak to 97w. Thanks for the detailed video - could not have done it otherwise. !! (VA6QAS)

[@martins3474]

I just bought an Icom-7100 because I wanted a new radio for my vehicle. Bought 12-Dec-2021. I also bought the optional HM-151 microphone. Full 100 watts output without compression. This was transmitted into a dummy load. I also sent the microphone to have Bob Naggy modify the element, add an ounce of extra weight to it and he also drilled the hole larger in the mic face and put more of a filter behind it. It now keeps the breathing and spitting sound away. I do not understand why my radio and others transmit the full 100 watts out while others complain. There is an upgrade to the firmware in 2016 but I think it was before this video was uploaded. I understand and have tested the stock HM-198 and find it really is not a good match to the radio. The optional HM-151 is and after the modification to it, it is excellent. Don't modify the radio because it has a poor stock mic!

[@TRXLab]

The newer radios don't have this issues any more Icom has modified it..

[@g4vft]

Peter. Just wanted to say thank you for all your videos. I find them very interesting and informative. And really appreciate you speaking English to include the wider audience like me. 73 Jon G4VFT

[@TRXLab]

Hi Jonathan, thanks for the kind words and thanks for watching 73

[@mavgk6155]

Sent to me from ICOM AMERICA: Thank you for contacting Icom America. I would strongly advise against performing that modification because: It voids your warranty Highly probable that you will introduce ALC overshoot What I can recommend is add 5-10db of Compression to bring up your average power.

[@TRXLab]

What ever you do you do it on your own risk. 73

[@RU2AIM]

Hello, Thank you for buying a brand new 3/4 power Icom. If you don't like being lied to about your Icom being a 100w pep radio you can always buy a Yaesu, Kenwood, modify your Icom ALC or go pound sand. Here at Icom we never admit to our own stupidity or mistakes in design or implementation, but prefer to blame you and call it something no one can disprove such as "static discharge" even though your new Icom was only on a dummy load when it failed. Thank you for your money, now please put up with the many problems and issues we have built into our radios, stop complaining and just go away. If we already have your money we no longer care to talk to you, period.

[@technos123]

Nice modification. I would feel a little nervous though that the radio was now putting out too much power. But as usual thanks for making the video really interesting.

[@ohmmeters]

Maybe we are so lucky that this modification made the modulation really clean and "unstrangeled" that the ALC now works as it should and that the "SSB-drive" in the setup menu have to be set lower because the factory setting had to be set way to high to compensate for the flaw in the ALC-design. (of course it was factory-adjusted with a pure tone fed to the mic-line and not a voice.. and therefore whistling in the microphone always gives 100w+ power output, and therefore Icom did not detect the flaw as they use a tone)

[@TRXLab]

+Lars Johansson Hi Lars, all tests before we released this were positive. We tested different cap values and found 10uF to be good. Mod is clean even with compressor. 73

[@keithschreiter3885]

Nice Mod to the ALC, The only thing I would do is add some RTV to secure the cap to the board as this is a portable radio and is subject to some harsh handling and can cause the solder joints to break lose or the pad to come off the PCBThanks Keith N9QDS

[@TRXLab]

+Keith Schreiter Hi Keith, you are absolutely right but of course the cap has been fixed with hot glue! Thanks for fee-back 73

[@glaros0]

Great modification Peter! I don't own 7100, but I was really surprised as to how come ICOM itself missed this obvious ALC problem before market release. That's one reason, I never ever buy new models until they have been extensively tried by ham operators. 73, Kostas.

[@TRXLab]

Hi Kosta, thanks for stopping by. Yes you are right it is always good to wait until a radio has proved that it works.. 73

[@fevo69]

This Radio is perfect! Here is the respond from Icom about the TX low power. Thank you for contacting Icom America. Icom's position is that the model 7100 is operating according to it's specifications and it's design. The firmware that you mentioned only allows the meter to operate with a faster sampling rate, it does not provide a "cure" or "fix" because (in Icom's opinion) the radio is not broken. We do not support the modification of the radio, and Icom could not do any such modification however, if the operator chooses to have it modified, that would be their choice. We appreciate your understanding.

[@RU2AIM]

And that is why I refuse to ever spend my money on a new Icom, I will only buy used and put my money in private hands, I greatly dislike Icom's attitude.

[@michelmoncy6562]

Hello. This modification also works on VHF ssb ??

[@phillipvt]

Hi Peter. Thank you for your video. I did this mod a long time ago after watching your instructions and it really works. This is really a great radio and I'm sure with new versions Icom has incorporated your modification in the latest design. I will check the latest Service Manuals and tell you if I find it. Thank you again. Well done well presented 73! de ZS6PVT

[@Mr_Meowingtons]

from what i am seeing they still do this new... how is this not a recall?

[@dave216dx]

Mate just got one last week same deal... I saw the lack of current draw and knew immediately

[@TheRadioShop]

Nice job on that Peter. They really had that one cranked down.Fly shit, I loved it. Laughed so hard. Take care my friend.

[@TRXLab]

+The Radio Shop Thank you Buddy, well may be components tolerances which has not been calculated in developing.. LOL yeah looks like fly shit...:-) Take care friend

[@beachsandinspector]

I passed the url of your video to some of my local radio club members as some have this radio and could be good for them to see the modification.

[@TRXLab]

+BeachSandInspector Technologies Hi, thanks for feed-back and for passing over to your friends. All the best 73

[@JackieAudio]

Icom 756pro3 the same problem. I wonder how to fix it on this rig? Someone does know?

[@coxtechnical]

Adding the jumper AND adding the capacitor breaks the AH-4 tuner functionality. The RF comes up slowly when the Tune Button is depressed and the AH-4 times out (rather rapidly). I left the jumper on across the transistor but removed the capacitor.

[@leoduursma547]

Same experience here : I always leave in the cap ( 10uF multilayer ceramic) but omitted the short.

[@shaneweightman]

Brilliant ,, my ic7000 only does 60 pep. Cheers Shane

[@TRXLab]

Hi Shane, good luck with the mod. All I have done are working perfect. 73

[@kj7element276]

So i need to solder the capacitor in-between the two pieces of fly shit right?

[@TRXLab]

you got it right lol

[@regularuser492]

Jeder video die ich sehe ist wie eine neue lektion ! Sehenswert ! All videos to see it is like a new lesson ! Worth seeing !

[@alexb1903]

thank you for this video! I had the same problem, sent it back to the dealer and it was returned modified.

[@Bobsbbq]

What did they do?

[@siradrianq]

Did mod some months ago along with N type for VHF /UHF connector and clock battery mod . 7100 spot on now G8HUA

[@TRXLab]

Hi Mike, glad that it works for you. Thanks for watching and comment. 73

[@scottgarvy]

Do you have a pic that shows the right lead soldering position better?

[@johnallsopp8260]

Interesting video Peter, does the mod not stress the PA? 73 de John G4YDM

[@armandoborges8150]

Hi David, I made the modification but after that the Radio no power output in HF, I have reversed the changes and same no power 0 Watts. Please let your recommendation to make a trouble shoot. TY

[@andrewmullen5770]

You're awesome man, I love that you break down and explain everything and why you do things. Thanks!

[@abtechgroup]

Would you not be better off using an audio signal gen for these tests....?

[@TRXLab]

no not needed in this case as it was not planed to align the radio.

[@matsbladh6359]

I wonder if this modification does have any effect on ALC function also in DV and FM- mode? I hope it does because I hear many IC-7100's having issues like unclear blurry distorted characteristic sound when I listen to other ham operators.. It sounds like over aggressive limiting of the modulation level that adds "artifacts" to the modulation. So, could it be that this is the same reason why it limited the SSB-output so hard and that both problems will be taken care of when adding this modification? Or maybe just maybe this modification only affects the SSB and that Icom have made a similar error elsewhere in the design? (I imagine that the reason why Icom did not detect this error are because a signal tone-generator and not a real wider voice-like signal is used when designing and adjusting the level of modulation and setting when the limiter should start to work). The SSB power is ok when whistling, but when a wider signal is input, like a voice it gets limited way to early).

[@TRXLab]

+Mats Bladh Hi Mats, all over the air tests also on FM sounds crisp and clear without any problem. Thanks for stopping by 73

[@the1spyderryder]

You can not use "average" in ssb because the output power has to do with the peak poweris directly proportional to your voice power, AND you have to use special test instruments to test PEP OR PEAK ENVELOPE POWER OF A TRANSMISSION.

[@peteride-kostic737]

I upgraded to firmware E5 and I confirm that the average and peak output power as measured with an external powermeter does not increase. I did the jumper modification only (I did not do the cap one) and I confirm the average and peak output power increased significantly. Unfortunately with this modification I lost the possibility to reduce the output power in SSB to about 10W which is something that I need to do for driving my external LDMOS PA. Note that in FM mode the power control circuit works normally with the jumper mod. I could of course use an attenuator between the IC-7100 and the external PA but I would prefer to avoid doing that and find a way to increase the average output power AND at the same time keep the possibility to reduce the output power to about 10W PEP. The idea is to be able to adjust the drive level for the external PA to the optimal one for each hf band but also the 6m band and the 4m band that are also covered by my external LDMOS Gemini DX-1200 PA.

[@the1spyderryder]

Do you realize that putting a cap on the AGC SLOWS DOWN THE ATTACK TIME OF THE AGC AND ALSO THE DECAY TIME, PETER, YOU OF ALL PEOPLESHOULD KNOW THIS.

[@DoRC]

there is a via next to the resistor that the cap needs to be soldered to. is it ok to solder to that via?

[@TRXLab]

where ever it is suitable..no problem. 73

[@ninaevans4501]

If surface mounted components get any smaller Peter, we'll need Electron Microscope spectacles in order to do repairs! LOL!! 73s Good Buddy.

[@TRXLab]

+Nina Evans Hi Nina, lol you are right I almost need a electron microscope by now lol. Thanks for watching 73 and all the best

[@DDSPL15]

Wonder what the peaks of the ssb envelope look like... Seems the peaks would be clipped & only limited by the PA's maximum voltage capability without the ALC reducing drive... Are you able to do a follow-up video showing the output on a scope with this modification? A theory I have is that one could 'trick' the ALC threshold by doing a 're-alignment' of the output power calibration procedure on the ic-7100 using 130 watts & scaling it for the lower power calibration points to accomplish similar ends, while also keeping the ALC intact. I guess I'm lucky though, my ic-7100 produces it's rated output, but I agree that the ALC on SSB is finicky w/ certain settings.

[@TRXLab]

+DDSPL15 Hi, we tested this mod before release extensively. IM3 with compressor is 28-29db and without compressor 31-32db related to the avg single tones of 44dbm in test configuration. If you would like to have the calculation on PEP simply add 6db to my test figures. Audio was tested on the air crisp and clean. Thanks for watching 73

[@DDSPL15]

+TRXBench At what power output was this conducted at? I wouldn't expect IMD to increase w/ this modification if the output power remains below the maximum voltage swing of the PA; THD can even decrease slightly as you get closer to maximum voltage swing on a Class AB amplifier. However, without ALC limiting, the only thing preventing a clipped output is the maximum voltage swing capability of the PA, unless one manually turns down RF gain to prevent the peaks from trying to exceed maximum voltage swing of the PA.I guess the IC-7100 could also do RF output limiting via Id current sensing, but I'm unsure of this and the peaks of the SSB envelope could be just as clipped depending on how it is implemented in the DSP and/or CPU. The PA output devices in the IC 7100 are rated at 70 watts w/ a 12.5 Vds, they are in complementary Class AB configuration which could "safely" allow for 140 watts PEP output under IDEAL conditions; my guess for the reason why 140 watts was the peak output you measured was likely due to some sort of programmed 'fail safe' hard current limiting of the output devices, thus no more current, no more voltage swing. If this Id current based RF output limiting is being implemented via the DSP by reducing IF output gain in a similar manner to how the ALC functions, then I guess the PA output could still be relatively clean on the peaks so long as the DC power input voltage was sufficient to maintain Vds voltage headroom. All of this is just a guess though, but I'd bet even w/ this mod that you won't see more than 22 amps of Id, which happens to be the maximum spec for the radio & likely programmed to be the limit as well. Did you look at the SSB envelope on a scope w/ audio, or perform any maximum power transient / pulse IMD measurements? I hope I'm not coming off to be negative about your video or your work as I do enjoy your channel; I just want to make sure everyone understands the full picture of what this modification may be doing to their transmitted signal :)

[@oe3fqufranz782]

Robert, viele Dank für die Modifikations Anleitung. Es hat alles wunderbar funktioniert. 73 de Franz

[@hillbilly4christ638]

So, I am wondering if this modification is going to cause some problems elsewhere.

[@TRXLab]

No is working fine ever since

[@leoduursma547]

Yes it does : AH-4 tuner does not work anymore.

[@Aleziss]

I was just wondering, why delay instead of changing the level of comparaison ? Couldn't you have just change the reference level of the op amp instead ? 10:18

[@TRXLab]

you always can work on different parameters to change a behaviour..One point is to find the easiest way to get the wanted result 73

[@Aleziss]

@@TRXLab indeed good thinking to find the easiest way to perform a mod like that... I thought by changing a single resistor value on the comparator would have been another idea but I see that it is really small electronic to work with, easier to add componets than replace a tiny resistor... I was wondering by the way, how come there is no parameter settings in the service menu for the ALC reference level ? Also, how is the signal output quality look like on a spectrum analyser after the mod ? (I don't know how this test procedure is called but it uses two tones and the RF output is monitored to give a nice sinus readout on spectrum scope on SSB)... And last thing, if you ever come by a IC7300, I would like to see the same mod and schematic study on that radio too !

[@PapasDino]

Peter - have you listened to the audio quality after you made the mod to see if there was any indication of distortion or did it remain clean? 73 - Dino KL0S

[@TRXLab]

+Dino Papas Hi Dino, yes you can be assured we have a 100% clean modulation even with compressor on an mic gain on 100%. We have extensively tested it before release. IM3 products are also clean. Thanks for asking and for stopping by! 73

[@nutlock2857]

Hi Peter thank you for another brilliant video Can I ask you- what is the SSB monitor unit on the bench? what does it do ? thank you again- 73

[@TRXLab]

+Nut Lock Hi, thanks for feed back! Regarding the SSB monitor you already have the links from the kind gents.. 73

[@RU2AIM]

I hope you put a dab of silicone rubber or equivalent on the capacitor where it meets the board or road travel movement from bumps will cause it to fail

[@G0NMY]

Hi Peter, A great mod on the ALC line. however, with the pa now producing about 135W + PEP how hard are the PA transistors being driven or maybe over driven? And also, It would have been nice to see the spectral purity of the transmitted signal. Maybe Icom had to limit the power to meet spectral purity specifications? A before and after video of the transmitted signal quality would have been nice to see, especially if the radio is to be used for Data transmissions FT8 RTTY SSTV etc? Last thing any ham wants is poor IMD and a splatter box!

[@TRXLab]

The THD is still in it specs and even 3rd IM products are still fine.

[@herbertsusmann986]

Peter, another great video. Did you check the output with a spectrum analyzer after the mod? Just wondering if you are now over driving the PA?? I probably would have used thin #30 wire to connect the new cap to the SM resistor. I would also glue down the new cap. Maybe you did all this or equivalent but didn't show it? 73's KA2ZOH

[@TRXLab]

+Herbert Susmann Hi Herbert, yes of course, we tested this mod before release extensively. IM3 with compressor is 28-29db and without compressor 31-35db related to the avg single tones of 44dbm in test configuration. If you would like the calculation on PEP simply add 6db to my test figures. Yes cap is fixed with hot glue. Thanks for feed-back 73

[@TRXLab]

+TRXBench sorry 31-32 db!

[@herbertsusmann986]

+TRXBench I should have figured your usual thoroughness meant that this was already checked out. You never know with this stuff and since it wasn't mentioned in the video I thought I should ask so others might see your answer also. 73s

[@TRXLab]

+Herbert Susmann Hi Herbert, no problem and nothing wrong with asking and rather more I should have mentioned it in the video so it was my fault. Thanks for your comments! All the best Cheers and 73

[@garycariker3072]

From the schematic, it looks like you could connect the capacitor from CP1501 to ground - making soldering much easier by avoiding the "fly shit"-sized components. If you agree, that is how I plan to implement the modification on my IC-7100.

[@TRXLab]

+Gary Cariker Hi Gary, yes from the schematic I would agree but have not in mind how it looks like on pcb. 73

[@Tom6x6]

+Gary Cariker -- Like This? dc5ww.de/ic7100/board_06.jpg

[@garycariker3072]

Yes, this is exactly what I was planning to do! Thank-you for confirming it will work.

[@Tom6x6]

You're welcome. I just completed the modification as shown in the (dc5ww) link above. It works great! Peter, I was listening to some of your other videos while I was doing the mod. Terrific! I really enjoy them.

[@garycariker3072]

I finally did the modification this weekend (18 June 2016) after updating the firmware to Rev E. The firmware made no difference. I installed the jumper wire, not the capacitor. That one change almost doubled the average output from 50 watts to almost 100 watts with no ill effects to the audio quality. I will leave it alone and probably not install the capacitor.

[@davemould4638]

Hmmmm. I'm not sure that driving a 100W radio routinely to 135W is a good thing. Will the PA survive long use at that power? I would say that 10uF is too high a value to achieve what you require and less than 1uF would probably push the PEP up enough. Additionally that giant 50 V part is over-kill, and why use an electrolytic when 805 size ceramic capacitors of 10uF 16V have been readily available dirt cheap for many years? I also don't see much point in bridging out the AM mode transistor.

[@DK5ONV]

Great job done, Peter! Happy new year

[@TRXLab]

Thank you Kirk! Happy new year!

[@mickwood4641]

Fantastic Video Peter ... Many Thanks ... One question ... I presume the little Fly SH.T resistor was removed and that you bridged the 2 points with the lead of the Capacitor ... Mike M0csi ...

[@rangersmith4652]

But what if the antenna is only a 100W antenna--did you not just create a situation where it's going to be overdriven by the radio?

[@SquantoTerror]

Nice modification Peter! Very well done.

[@TRXLab]

+Nicholas Hyer Thank you Nicholas. 73

[@ub4cau]

Hello. Mounted 10 microfarads, on the transmission there are bad spitting sound on self-control. Mounted 1 microfarad was excellent ALC. Put 1 microfarad!

[@jeffpowell662]

I Bought a IC 7410 and I sometimes wonder if I should have purchased a 7100 . I see or I don't think it has a built in antenna tuner, that is a con I am perfectly happy with my radio I only like the Dstar option and the uhf vhf option. Maybe some day I will purchase a IC-9100 that has it all. I guess I have some deciesions to make. I will really hate to get rid of my 7410 it has been flawless. N3SXW

[@mike-M0MSN]

Not seen a lot of you recently are you going to do more, I am missing your uploads

[@z.i.3425]

Hallo Peter! Betrifft die 140W PEP. 'Hast du dafür via Service-Manual die Max-Power durch Programmierung erhöht? Der TRX ist so bei 100-110W eingestellt und es sind Reserven vorhanden.

[@TRXLab]

Nein an der Soft Einstellung habe ich nichts geändert...

[@z.i.3425]

@@TRXLab , da geht nämlich noch mehr. FM150W, trotzdem noch sauberer Signalverlauf. SSB-PEP müsste dann bei 180-200W sein. Die Icom-Geräte haben nämlich die Endstufe der 150W-Marine-Geräte onboard.

[@beekeeper8474]

Wondering if this is still a problem I don't have a pep meter so couldn't test

[@carlosfjr9598]

Hello, very good work and explanation, congratulations. I have a question about IC 7100 and this change made is about updating firmeware released by ICOM to resolve this low power, I do not comment your I was curious to know if would have to make its modification along or not the update of ICOM, thanks.

[@TRXLab]

+Carlos F Jr Hi Carlos, you should do the firmware upgrade in any case first and see how it works. Our experience is that the difference is not that huge. After that you can go for the hardware mod. Thanks for watching and feed-back 73

[@jonc4271]

I KNOW I COME UP WITH SOME ODD QUESTIONS, AS I WOULD LIKE TO KNOW IF ANYONE HAS FITTED AN ICOM 7100 INTO A WORKING TOWER PC ??? IF SO, HOW WAS IT DONE. MANY THANKS IN ADVANCE, FROM KNOBBY IN THE UK

[@CT1ELP]

Hello Peter, nice work ! I have a question, why have you bridged the transistor ? Why not just put the capacitor to hold the voltage and make the alc slower , isn't that enough ? If the transistor is used for AM mode control shouldn't you have left it like it was ? Thanks and 73!

[@TRXLab]

+CT1ELP Hi Pedro, it is important to get the right balance between speed and performance. The mod will work as well if you put in the bridge only but it is not so efficient. If AM is engaged the transistor is switched on that is like a bridge.. so no problem. Hope that helps 73

[@stevemobile1]

gr8 video....icom 7610 has same issue .will you be doing a video for ic7610 ???

[@RU2AIM]

So does the 7300, mine went up to 127w pep from a previous max of 96w pep and everyone noticed how much richer was the bass in my audio after the ALC mod.

[@thunderbuilt77]

what does signal look like on the spectrum analyzer now?

[@guillaumevidal2837]

Thanks a lot for this great video (Again!!), did you try same workaround on ic746 (non pro)? I found the power in SSB to be 40 to 60 Watts while 110 in RTTY. I located IC971b on POCV line but I'm unsure how to adapt your work. rgds, 73's G

[@michaelcarey]

One more question Peter. You used a 10uF 50V capacitor, what is the lowest voltage capacitor you would recommend? Would a 35V be OK? 25V? 73 VK5ZEA

[@TRXLab]

+Michael Carey Hi Michael, well a 25V cap is fine no problems. Good luck with the mod. 73's

[@michaelcarey]

+TRXBench Thank you once again! 73

[@francoisdavenne2162]

dear , is the ic-7300 is the same modification? it seems to be the same unit?? i need your helping BR

[@z1power]

Thanks for the video, I always learn a lot from these.

[@TRXLab]

Glad that you like it, thanks 73

[@hancecrawford]

It is amazing what you can do when you know how well done :)

[@TRXLab]

Thank you John, well time and bad documentation is always the limiting factor... 73

[@cliffbarrimore]

I know this is an old thread/video, I did the mod on my 7100, have a slight issue, wonder if anyone else has this.. I have the Icom AT180 and a diamond mobile antenna, with the mod'ed radio, when I key (very noticeable when I use the SWR test) the power and tune bounces very rapidly on the bar graph. when I use it to talk the tuner will cut in and out and then the tuner goes out of line alc exceeds the limit and then cuts power. remove the capacitor and all back to normal.. is this a bad capacitor, or rf getting back into radio. mod removed at moment, any thoughts? thanks

[@artdodd815]

Did you put the bridge in front of 1508 on top of that hole on the PCB. Thanks Art. Last question😀

[@TRXLab]

oh wow Art, I can't remember sorry

[@belinaakina6872]

Please do a video for icom m710 for this modification

[@harry4516]

Vielen Dank Peter für die detaillierte Beschreibung. Exzellentes Video !

[@TRXLab]

Vielen Dank Harry HNY 73

[@Scott-K7sce]

like OMG he said Fly shit... i never laughed that good in a long time.. thanks for the comedy :-)

[@TRXLab]

+Scott Edick LOL, you are welcome, glad you like my comedy :^)! 73

[@ohmmeters]

+TRXBench We use the very same expression about those fly poops : )) LOOL

[@dougtaylor7724]

Can that radio be converted to transmit on 630 meters?

[@martins3474]

Look up ICOM-7100 MARS/CAP MOD and you will get your answer

[@2E0KOL]

Hello Peter, I'll be doing the 'Fly Sh-t' mod at the radio club tomorrow. Thank you for the info and I'll let you know how we get on. 73 from Colin 2E0KOL.

[@TRXLab]

Hello Colin, very good! Good luck for the project! 73's

[@14AY022]

Hello Peter, thank you for this video that I have just discovered. If I understood the fault comes from the circuit which limits the power when the SWR is high. Do you confirm that after this modification the power circuit is no longer protected? Indeed I am going to use an IC-7100 with an AH-4 and I am afraid at the beginning of the tuning of the tuning box the ROS being high this destroys my RIG. What do you think of that?

[@martins3474]

After the mod the AH-4 doesn't work properly.

[@cliffbarrimore]

Hi.. I have read that just doing the Jumper with the E5 firmware does the same job, can you possibly confirn that the Cap is needed or not, I cant see that a firmware upgrade can fix a 'design flaw' , but it would be good if it could be tested to see what it does do, Just about to purchase a 7100 and would like it to have full out put power :-) great Channel Thanks ! Cliff

[@TRXLab]

Hi Cliff, if the new software and the jumper is doing the job, it is just fine. We found different behaviour with different radios....73

[@rafaelmoreno79]

hi Peter,i know this video is old but i find it very helpful, i got a new icom 7300 that had the same issue right out of the box,i did the mod on it and i am very pleased with the end results,it was doing no more than 60 watts on ssb mode and now it does about 135 to 140 watts after the modification,i used a 4.7 microfarads 16v capacitor, will it work better if i had used a 10 microfarads capacitor as you used on the icom 7100? thanks for the great and useful videos Peter 73

[@k2icc]

Do you get schematics or service manuals from Icom or any other vendor?

[@danford7532]

Icom designed this radio with this overly protective circuit as the knew the transmitter had massive overshoot issues. If you mod your rig you will shorten its life, and or destroy the solid state amp you may use with it. If you use a tube amp, you will shorten the life of your tubes!

[@xMarHazKx]

hi, i am experienced electrical/electronic engineer, have the ic7100, would like to know is there any possible/expected damages in few years later after this modification done? and whats the different from your point of view if using 50uF or 100uF instead of 10uF capacitor? 73 de 9w8haz

[@roberttodd521]

Will this mod work on most icom radios? Ic718, my ic 756 pro 3 only gets to around 75 to 80 watts, I am in a motor home and running on batteries , at 12.5 volts output power is down, at 14.2 when batteries are charging, no problems , easy 100 watts. My ic 7300 does not have a issue at 12.5 volts easy 100 watts. Just interested if all older icom Hf radio’s would work with this alc mod ?

[@dave216dx]

How did you get on with your pro3 Robert?

[@bradcfi2]

Hi Jerry, Great video. Very low average and peak power was the first thing I noticed when my new 7100 arrived. My solution was an amp but now I want to install in my truck. There is another KZbin video where the guy just did the jumper and not the capacitor. I thought your video said the jumper was for AM but his power went up on all bands SSB and the power delivery seemed more aggressive than your mod. What are your thoughts about just a jumper? Also, I am having trouble locating a radio shop to complete the mod. Do you know of any in the states? Thanks again for your videos. I am learning much. Brad

[@MrTalaue]

I wonder who will see the difference of 1.5dB on the receiving site.

[@beekeeper8474]

I really wish I could ship you the new ver2 to see what you can find out

[@dougsnova1]

I did this mod,on SSB it works fantastic on AM not so much.Where I once had good forward power I now have massive backswing.Should I remove the bridge?

[@TRXLab]

Hi, no it should not influence AM check for solder bridges. Hope that helps. 73

[@matsbladh6359]

Mine is also huge negative influence on AM, I suspect that applying both mods are a little bit too much.

[@dougsnova1]

I have talked to several people who have done this mod and all say the same about getting a massive back swing on am.I watch the Amp meter on the radio and it shows drop on the draw matching the radio's back swing. I wish he would have shown AM mode on the video,after any mod should always test on all modes..

[@Scotscan]

I honestly hope that this mod will not be required on newer models. As quoted, should be seeing 100W PEP from these units

[@TRXLab]

no not anymore. They recent radios are fine

[@chrispeters7520]

Hi Peter Is this mod necessary if the radio has the Version 5 update installed?

[@TRXLab]

+Chris Peters Hi Chris, I would always do the lat firmware upgrade first. After that you can do the mod... 73

[@sagaertj]

Do you have a modification to allow it to work on 60 m ? 73's ON5DI

[@ohmmeters]

+Johan Sagaert There exist a mod that opens up the TX on HF ... after that it will TX from ~1.8Mhz and up without gaps..

[@TRXLab]

+Johan Sagaert Hi Johan, yes a MARS mod is on the internet. 73