I just picked up a 746 for 300 bucks with a bad tuner. Both motors had the separation issue with the ferrite core and plastic gear. I used gorilla glue gel and followed your video to a T and after an hour or so, my tuner is working very well. Tunes all bands pretty quick. Thanks for the video, it was a BIG help.
I am simply blown away by what you know about electronics. I worked professionally at it for 30 years, and some of the info you are passing along I had forgotten in the long ago past, but more so, you are teaching things which I never knew, or never heard of! You do have confidence in yourself which is part of the battle, but you are repairing components most of us would just replace. It wouldn't surprise me to see you change a transistor inside of an IC. :). Thanks again for sharing. Your work is much appreciated.
Thanks for the great comment Stephen! I'm glad you are enjoying the video's. It's my love for all things electrical, that keeps me going with this hobby. (sometimes mechanical too) Next time I change one of those transistors, I will do a video :^)
Absolutely true, Jeffry. I've been 51 years as tech and 41 years as a Ham and this brilliant young man Paul is making me feel like a dodo. How can one so young (I'm in my 70s, so everyone under 45 is young) acquire such knowledge?
Stephen Moore Some viewers need to come together and put together a nice ion beam for Mr Carlson, along with a micro wire bonder. He’ll be repairing ICs in no time :)
Hello, sir! Joel, W9JFK here, in 2022....and you just helped me repair my IC-746. It had EXACTLY the same problem with EXACTLY the same motor. Thank you so much for putting this information out there. 73 & God bless, Joel.
Have watched your videos for years, and have always been amazed at your knowledge of not only tube technology, but of modern day circuits. What baffles me, is to have that kind of knowledge, and be no older than you are. After much thought, I have come to the conclusion that you are an alien. That's the only thing that makes sense.
Hello There.. Let me tell you a terrible story.. I sold my IC-746, but when the buyer received it the box looked like it was abused. When he opened it he said the volume was stuck, so that made me believe it has been dropped. He sent it back and it sat on my shack for about 1 year in the same box since I didnt want to look at it (it was too painful). Finally a few days ago a took a leap of faith and I opened it. I was able to control it through the ICV so I knew all was good, except the "ANTENNA TUNNER". Thanks to this video I was able to open it and fix the problem with the motors. Thanks sooooooooo much for this..
I was contemplating buying a 746 with a "tuner does not work" issue. After watching this video, I decided to go have a closer look and found it had a very similar sound when trying to tune. Well ... I bought it. When I got it home I followed your steps and discovered the motors seem to be OK, but both couplers are cracked. Thanks to watching this video, I was able to buy it at a deep discount and an easy fix!
I had exactly the same problem with my IC-746Pro. Just one motor, same side. After watching your video I decided to try fixing it before searching for a replacement. A little CA glue and some accelerator did the trick. Thanks for making the video!
Thanks for posting this. My 746 had the same issue, which developed about a year ago. After watching this video, I worked up the nerve to tear the radio down and try this repair. It' worked like a charm. The 746 is now back up to 100%.
I used to own an IC-746 and as with most of items I sell or trade, I wish I had it back due to not only for HF but, this rig features a full 100 watt 2 meter capability. I absolutely did not know it had motor tunable capacitors in the tuner section! Most auto-tuners I know of only use relays to switch fixed caps and inductors for tuning... a very noisy process. I personally only have seen motor tunable caps on high end high power auto-tuners. I have gone through several HG radios since the 746. I have bought and sold a FT-1200, IC-7300, FTDX-101d and now have an IC-7610 which I love! I also just purchased an IC-705 and have found it to have a great receiver. Thanks Mr. Carlson for another great video in which I have learned something I did not know before! GL.
Personal game... how many minutes into the video before I know I'll never get the radio reassembled again! Fantastic troubleshooting and fixes, Paul! Thanks for your uploads.
Just subscribed after watching the Yaesu FT 1000MP repair and mod. I really appreciated watching your logic and repair. Really liked how you repaired the motors in the Icom, instead of replacing the parts with parts that would likely fail again you went to the extra effort and modified the motors to be more robust. It wasn't just a repair but a failure point upgrade that was simple and logical, just awesome!
All your outstanding knowledge and experience that you so kindly share you have the number one key to great RU-vid viewing - you know how to tell a great story and you do it with unbridled enthusiasm. Thanks again for creating such great content and just sharing what you know and love! That's what RU-vid should be all about!
I wished everyone was like this, fixing things instead of just trashing it for one little problem. This reminds me of myself, spending countless hours dissecting parts and repairing them, and sometimes just to have a look. I can appreciate skills like this, takes the time and does it right. I found this video very interesting, he did exactly what I'd of done.
You do rock "C" man!!! ... it is a pleasure to watch someone as yourself make this work simple and fun to watch, and you take the mystery out of radio repair thanks!!!!!!!!
This is an excellent instructional video on diving deep into the IC-746 auto tuner to the point of component level (the tuner motor and gearbox) troubleshooting and repair. Icom's electro-mechanical tuning design for their older transceivers is fascinating on its own, and Mr. Carlson's video takes us on that journey. The narrative is clear and smart with excellent photography, ultimately being an entertaining and educational experience. Thanks!
I've always run into struggles when troubleshooting such things. I'm not an expert by any means. But in watching your videos about restoration and troubleshooting, I am catching on to many things that will help me: 1. Application of some common logic, where before "I was too close to the forest to see the trees". Couple a methodical approach to logic and I believe I'm on my way. I should look for the obvious instead of over-thinking a situation. I'll keep watching your videos; you have tought me a lot! Thanks!
You sir are a VERY good teacher, apart from a real life engineer-hacker. Thank you for your efforts and especially for sharing your knowledge and protocols!
I just started watching your videos, great stuff! I only repair old vacuum tube radio so I am about 70 + years behind all of this! Still very fun to watch you troubleshoot and repair.
I just love watching you work with such ease, i have no skills but know some of the components and some basic knowledge of what you are doing. so interesting do . Thanks for allowing us all to watch and learn from you .
I repaired the motors in an IC-756 I had (thanks to you) about 10 months ago. Since then I have watched most of your videos. This is one of the best channels on RU-vid! Thanks! Travis - W8BT
Mr.C...NASA should have you as the director..you are absolutely brilliant...I somehow landed on this video..have no electronic experience but found myself enjoying your easy and calm delivery..you earned my sub!
Tnx Mr Carlson very nice. I follow your video and fix my 746 also. Now i have to Repair Backlight also. Never done such stings before. So it´s great with those videos. thank you so much from SM7GQF
I bought my IC-746 new and sold it a few years later - something I have always regretted. I hope to one day find a like-new 746. I wish Icom still made these - I would buy one in a heartbeat.
Hi Mr Carlson, really enjoy your videos. I am a fixit-man working in office machines [and others way down here in Auckland, NZ] and noticed your repair of the electric motor/gearbox unit in this Icom IC-746 is very similar, but much smaller, than the ones we find in laminators. My fix is similar to yours, disassemble, clean,glue, and reassemble. I use two-part Epoxy as I have had some failures with supEr GlUe. The epoxy fix has been out there for a couple of years and none of the fixed rotors have let go so far. It is indeed a shame that some well designed machines are let down by penny-pinching bean-counter politix. The major looser is the poor old customer! When the ManufactUrer says "No spares, buy a new machine" and we fix 'em and give the customer years more service out of it, well, it really makes us proud. I have been completely smitten by your Echophone EC-1 and cannot stop thinking of it. Now I have to track one down for myself... The video you did on the resoration will get Eleven out of Ten on my scale. Excellent work. Outstanding. If you ever want to sell yours, or if you know of one for sale, I am keen to get my hands on one!
av8bvma513 Hi, Thanks for your thoughts and ideas. Glad you liked the Echophone video. If I find someone that wants to part with their receiver, I will let you know. Thanks for the nice comments!
Nicely done! This is the third video of your's I've watched in the last 24 hours and I'll be watching more today. You make working on radios/VTVM's look so easy. I'm envious!
ahhh... Spendor in the Lab! You make a nasty repair look almost simple. You have learned, I'm sure sometimes through trial and error, but most of all through careful selection and research, what works and what doesn't. Learning about the zillions of different lubricants, metal to metal, metal to plastic, and plastic to plastic combinations that they work or don't work at all with was a decades long learning process for me. You simplify to the point of making it an art. LOL Love that 746. My 751 still needs love. Bruce KQ2E EDIT: It is now 10 months later and I'm grinning like a really happy ham as I look lovingly at my NEW Icom 7300 and Astron 35M. Can't wait to see whatever you do to a 7300 to make it an even happier rig!
You must have the patience of a saint to do what you do to these radio's, one hundred percent informative each one. another 10 out of 10, keep up the great work
Amazing! Your work quality and method is very inspiring and you have the gift of getting it across on RU-vid. This is going to be a very successful channel. Keep up the good work and thanks for the video!
Interesting solution to this problem, I have an Icom IC-756 pro II and if I ever have an issue with my internal automatic antenna tuner I will look at the motor gears and see if mine has the same problem. Thank you for your very detailed instructional video.
Good job - keep the videos coming. I'm also a ham and have had to repair an FT-450 several times. One issue was the original CW jacks were crappy, and another was the volume control started feeling like it had sand in it. Was able to take the potentiometer apart and fix the issue. It's good to be able to fix things on our own.
There are “old” spectrum analyzers and wobbulators that use a motor driven capacitor for sweep. The capacitor then has no stops and rotates continuously.
I have an Icom 746-PRO that I got from a local ham's estate when he passed away. It's quite a nice radio, I love it very much. That display bug is very common, I've heard of it failing just like that.
This is a great video. Concise, well shot and extremely helpful. I just bought a 746 and the tuner was working when it left the sellers and it appears that one motor is bad. Considering the construction of the motor mounts a solid drop could easily damage one. It surprises me they are not screwed to the frame of the tuner and shock preventive is the coupler, like it is in most machinery. Seems the mechanical designer got left out of the tuner electronics design. Thanks for this wonderful video, now I can see how well these old hands work!
+Mr Carlson's Lab This is my first Icom other than 2 meters, been Yaesu and Kenwood for HF person, but recent radio design by them made fixing them an outsource. The 746 is solidly built and actually accessible compared to the others. Industrial designers always get left behind once the electronics guys take over and in this case defeated the plus's the aluminum frame provides to protect vital components, like the stepper motors. I am going to take a shot at this this weekend and hope a motor being jarred is the only issue with the tuner. I did add a micro fan to pull cool air past the LCD which evidently also a weak point.
Second video of yours I have watched in the last 24 hours (the first being the FT1000MP repair - what a dogs breakfast that radio was!). I had to do a lot of repairs to my second hand IC746pro to make it go properly, it had no RF power out, and it wouldn't switch antenna's. Then I found out it was "opened up" (TX anywhere). I know your pain when you don't want to go back inside a radio to do more work on it! I also modified mine so the Q1 on the RF board has a heatsink, IC151 only gets power on TX (instead of idling all the time) and the fan runs at reduced speed during RX. Then 3 weeks later the backlight died. So out came the SMT transistor (a pain to get that shielding can off the inverter) and in went a TO 220 package replacement just like you did :)
Mr Carlson's Lab No worries - yes there are heaps of silly problems with these. I completed all the upgrades and repairs in two sittings after reading and watching youtube videos. The other problem mine had was a dry joint on the SP OUT jack at the back. Mine was a very sad radio, but I did get it quite inexpensivly.
Ditto here: i have an IC~9100 & it looks like the tuner is identical, so if it fails ill know what to do. Thanks! Mike N7MSD Edit: also have my Elmer's old TS~850SAT also with a motorized tuner. He had it a long time so I'm guessing Kenwood didn't cheap out by using plastic gears like Icom..:(
That would be patience. Patients are quite different things, though it could be implied that the pieces of gear being troubleshooted in these videos are the patients. The good doctor Carlson cures their ills. Terrific videos. Well produced and very informative.
Thank you this helped me loads. I serviced my AT 180 Motors and it is working better than new. I used sewing machine oil to do the job. And yes both motors had the same problem.
Hi Paul, another great video and repair.It never ceases to amaze me why companies continue to create these cheap plastic parts and geared electric motors that will always break down ,given enough time and use.We have had these fail constantly in our Government printers requiring large numbers of expensive service calls.For the small price of some internal upgraded materials, companies would save tens of thousands of dollars in service repair costs .Dana WN6OHG 1965 Novice to Extra Vlass. 73 db
Quite right !....my son has an electric race car that strips out plastic gears in the transmission, as fast as you can replace them.Nothing like shoddy materials.You have to look hard to find quality products and it is a crying shame indeed. Peace..
Also, I have worked on the 180l-17, it's a hf tuner used in the wingtip of the old B747 aircraft to tune the 12 ft HF probe antenna. It , too, uses 2 motors, one to drive the variable capacitor and one to drive the flat metal wire inductor, but they are massive capacitors and inductors, extremely heavy, as the Collins 618t Transceiver which drives them are rated at 400 watts PEP, and they have to operate at 40,000 ft in -60Deg temps. They fail, (not too often) mainly due them being a rugged mechanical device, and they re tune every time you change frequency.
I just purchased an ICOM 746 Yesterday with the same issue with the antenna tuner.I have decided that I will just purchase an external automatic tuner & not worry about it working. The radio works great on all of the bands & for the $350 I paid for it I promise I more than got my moneys worth with or without the tuner ever working.The last owner just did the back light repair & I'm guessing he had no idea the tuner did not function since he uses a 3 element SteppIR beam.
I sold that 746 several months ago to a friend who repaired the tuner.I just purchased another 746 a month ago from the estate of a local SK and it is out for repair now for the tuner. It is $100 for the repair for the tuner.
Man, they made such a big leap with the 7300 ive not had a problem yet! After your vids tho im tempted to get inside and just firmilurize myself with it.
Great video! An idea for epoxy is Acraglas, which is a 2 part expoxy used for rifle stock bedding. It bonds to about anything, and the best part is it doesn't expand when it dries (less that a 1/10%). Ive used it to repair rifle stocks, Mercedes instrument clusters, and anything else I don't want to come loose again. Brownell's supply carries it.
Ha! mechanical work also! I am enjoying your videos. My extent of electronics is diodes, rectifier bridges and regulators in alternators. All of what I recognise in a lot of your videos. Of course I get the relays and transformers as well also. Thanks for sharing. Maybe this old dog can learn something! From what I have taken from your videos you can draw a lot of parallels in comparing a lot of circuits. Amazing!
Hi. I allways have been an electronic entusiast and i make some repairs myself, you way to work is just amazing, after start watching your videos i totaly changed my way of fault finding and to work and the results are amazing. Thanks for that and continue the great job. 73 frok CT3LG
Thank you for sharing this..... I have an original IC756 and I can handle the 'lines' in the screen, but not the loss of my tuner.... The motors are built pretty much the way your IC-746 is.... Once again, THANKS...... 73
Thanks for the lesson Paul.I'm going to buy a 746 for a spare and run it mostly on 2m sideband and 6m.and a ant good to 15m.My other radio is a Ken.590sg.There's a group of hams that I've been talking to sense the early 1990s on 3.788-or787.6am to 8am, then a Canada net comes on at 8am.Like to see you get on and join us some morning.73 from Ronnie kn4u.one of your patreons.
I notice that instead of replacing the part you try to fix it first. I always try to do the same. I enjoy watching your video's. Thanks for sharing brother. 73's kg2nc
Ruben Got to make the most of this "throw away" time. Another neat perk of repairing this stuff; you get to see what was going through their head (or what wasn't) when they designed this stuff. Thanks for your comment!
Great! I was in trouble, when i opened microwave ovens timing and switching clock mechanism, because it was jammed for some reason. I opened it up and all gears game out. It took me about 4 hours to imagine how they were there. It was a nightmare to my little brains. In the end i managed to reassemly micro wave ovens clock and it work very well. :)
Such a nice radio and then these motors inside ... They are very much like the 28byj-48, often regarded as "the cheapest stepper motors available". Who else had an 101hero 3D-Printer and recognized the motors at once? ;-)
You really do need to get proper jewelers screwdrivers. ;) I enjoy watching all your vids as does the wife. I especially like the fact you don't ramble on about extraneous things totally unrelated the subject matter at hand.
The opening shot of your eqt bay has more test equipment than perhaps the space shuttle. Great breakdown analysis. You must have some clock making skills too. Very nice repair. Super glue is amazing stuff if you know how to use it.
I also use the term "hex key". Seems like down here in the south though most everyone says "allen wrench". So when i say hex key i usually get an odd look :-). Enjoying your channel, another great video sir. 73
As Garth would say "Most Excellent" video. I am always impressed with your presentation style. If you need a victim for another video I have an old TM-733 that I have been thinking about sprinkling holy water on. Lol
I have the same transceiver and mine just may have the same problem, now I know what to look for! I do have to comment on your tuning procedure as I tune mine differently. I simply hold the TUNE button down and it will not only turn the tune on, holding it a bit longer will make it go into the tune mode where the rig will go to low power and auto tune in CW mode. But your way seems to work as good. Nice job! 73 Rod KB8DNS
+poikaa3 I like to use as little power as possible to get through the tune... Just easier on parts. Sometimes the SWR will change with the power output level, so I test it again at higher power when it's through the first tune cycle. Thanks for your comment!
Hey - good video there. I've already re-done the LCD display supply much the same way you did. TO-220 package screwed right to the wall. My auto tuner is also knackered and have been putting off digging into it. The way this winter is going here in CT, it may be weeks before I resume the motorcycling activities so I might have time to dig into the pig.
Thanks for a very instructive and delightful video - I learned yet more about how to diagnose problems that seem impossible at first, but are a breeze if you approach them methodically. No specialized tools - no complex test equipment - just simple diagnostic techniques that are usable for all sorts of problems. Awesome..! Mike - AA6ML
Had the exact same fault on my 746, even the same motor. I called Icom and they sent me a new motor, although the design changed somewhat and a connector adapter is needed. Haven't had any issues since.
I'm surprised that after 8 years apparently no one has mentioned this, but those parts you glued together are friction clutches. They are designed to not be one solid piece on purpose. You were onto something when you said "I wonder why they didn't make them like this to begin with". Their purpose is to slip if the motor tries to rotate beyond the travel limits of the capacitor, keeping the gears from tearing themselves to bits. There is a similar type of friction clutch in the gear assembly of automotive power windows.
I have one of these lovely IC-746 radios. It hasn't given me a lick of difficulty, and I hope I don't have to contend with the antenna tuner issue. But at least now I have a clue on how to. :-)
