Capacitors And Electronic Troubleshooting - RCA CR-88 Radio Receiver!

Capacitor replacement and electronic troubleshooting, let's see how this improves the receivers performance. Bathtub capacitor knowledge contained within! This is Part 3 of the RCA CR-88 Restoration, a part of the GRR Series. To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: / mrcarlsonslab
Part 1: • 1946 Secret Listening ...
Part 2 here: • 1946 Radio Receiver Te...
Part 4 here: • Receiver Restoration S...
Part 5 here: • Electrical Troubleshoo...
Part 6 here: • Electronic Circuit Tro...
Part 7 here: • Find Intermittent Elec...
Part 8 here: • 1940's Radio Receiver ...
Part 9 here: • Restoration Adventure ...
Part 10 here: • RCA AR-88 And RCA CR-8...
Restoration finished: • Finished! Restored 194...
#restoration #electronics #repair

[@MrCarlsonsLab]

To learn electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here: www.patreon.com/MrCarlsonsLab

[@NotGonnaSayFO]

I am leaning towards becoming a patreon. I see there are different levels. Do all levels have access to the tools you have invented, such as those in this video, or are they only for certain levels of patronage?

[@qzepher]

Yes, I am a Patreon member. Dave

[@scottwelch1148]

I grew up in the Arctic, and shortwave was the only way to listen to the radio. When I was 10 years old in Resolute Bay, I had this exact same receiver.

[@MrCarlsonsLab]

Thanks for sharing your story Scott!

[@unlokia]

Gosh it’s a short one today. Seriously, people think one hour videos are “really long” - nope - the longer the better, as he doesn’t miss anything out. ❤

[@adeletanner2262]

Hi Paul. One of my duties while at Raytheon back in the early 70's as a Scientist's Assistant working on the E-3 AWACS Radar and Patriot Missile System designs was fabricating both small, large, and monstrous wiring harnesses. One skill set I aquired along the way was using waxed line, made of high tech polyesters, to wax lace wiring harnesses, some often 2 inches or more in diameter. Small or larrge, each harness was built on plywood walls, with nails driven into them to act like guardrails for the main harness and each branch line, and I often found myself in a huge room at the top of a 24' tall ladder working on a wiring harness some 100' long. So now, here i find myself watching yet another one of your outstanding videos and one of the first things I notice in your CR-88 is the exquisite wax lacing done back in the 1940's by someone who obviously took pride in their work. Just look at how the harness loops are equally distanced from one another and how each loop tie junction is in a straight line with the next. What perfection! Btw, one of the primary reasons why harness line is waxed is because when you pull the line taut at each loop tie junction, the wax, via friction, will keep the line taut and fixed in place like a knot, without your needing to tie one. The WW2 Veterans that taught me how to lace took great pride in their workmanship and instilled the same in me. So now, after some 45+ years repairing boat anchors, I still find myself taking time to admire a rigs wax lacing and reminiscing about days past and my wax lacing mil-spec wiring harnesses... Keep up the great work! 73's

[@MrCarlsonsLab]

Thanks for sharing your story, and taking the time to write Adele!

[@itsonlyme9938]

When I left school at the age of 16 years old and here in the UK my first job was working in a telephone exchange in 1965 was using wax cord to tie all the cable's together. I was also shown how to remove the insulation from the wire with pliers because wire stripers might nick the tined copper wire and fracture it cause it to break.

[@genestatler2514]

Thank you Paul for this series on the CR-88. I was a radio operator in South Korea in 1954-55 and find these videos fascinating. By the way, your new lab is fabulous. Regards from Tennessee.

[@johnbeckham1483]

Mr. Carlson, you have certainly demonstrated the importance of having quality testing equipment in this case checking the overall life capacity of a capacitor no pun intended! I thoroughly enjoy watching you troubleshoot & repair your electronic components indeed! Thank you...

[@leetucker9938]

Mr C super probe is well known . nearly every repair channel pays respect towards the super probe. it truly is a super probe 😗

[@afnDavid]

I predict that the Racal receiver will offer the best performance. Have used quite a few Racal radios and have always been impressed with their specifications/performance. now own: 2x Racal RA6790GM aka R-2174(P)/URR 2x Watkins-Johnson WJ8716 similar to AN/URR-74(V)2 1x Collins Canada HF-2050 aka R-5099/U

[@MrCarlsonsLab]

Those are some nice receivers David.

[@graemebrumfitt6668]

Didn't realise this was over an hour long was so engrosed, excellent job as always Paul and those dials spin SOOOO nice! TFS, GB :)

[@riccroll8190]

Your videos are so relaxing! Actually, most of the time, I don't understand anything about what you're actually doing, but somehow I like it anyway. I don't want to learn how to fix something like this myself, nor do I really want to understand how it works, but it is just cool. I just like the functional Esthetic. ...can't really say why I enjoy watching the videos so much. maybe because it's such conflict-free entertainment that gives an insight into a mysterious world and gives me an impression that the "magic" somehow works, like a journey through time to this exciting epoch of departure from which the devices come. it is also told in a very relaxing way. Thank you for your videos!!!

[@nyckhampson792]

I have to say I know not very much re electronics , but I watched all this episode and will warch more ....amazing Mr Carlson Nick Ireland

[@michaelellard4664]

Love to see your skills and one can use them without having to rely on computer software.

[@dffabryr]

It is amazing the fine work made by you Paul, you are a great teacher and your knowledge and experience is really amazing. For now I do not have time nor the money to work in some of the old rigs I have but I do really enjoy your videos. Beyond that, for the non English natives you make things even easier. Ah! that receiver has a beatiful audio !!!!

[@rubberscorpion]

Hello Mr Carlson :) I am vintage "old" school and I used an RCA-Riders Chanalyst Model 162C , Sure I only did the vintage old AM and SW Radios also Amplifiers back then. That RCA did it's job and well back then. It really is a lower sensitive unit I guess than what you are using here. I sure would LOVE to see you repair/rebuild an RCA chanalyst 162-C on your bench :) Then also available back then to us Old Farts was the RCA Audio Chanalyst Sound System Test Set Model 170-A. I doubt that many of them exist anymore , but I still have my 162-C and not used like it was now. I bet it will need many caps replaced. I also have my Hickock model 670, 1951. I am 70 years old now, doing projects as I can being on SS retirement. I love watching all your videos. I just wish I could afford to join in on your Patreon. Maybe you could offer us old timers on a fixed income a discounted rate ? :) Your electronic friend, Wayne

[@pomme4682]

What a beautifully presented competent account of restoration of a post-war valve receiver! As someone who has spent many years servicing old equipment I found the most common reasons for failure were due to moving parts such as switches or connectors of any kind, especially valve (tube) bases. Next came electrolytic capacitors which after many years might leak, or dry out internally. They do of course need to be supplied with dc to keep their dielectric films intact. For that reason such capacitors are coded with dates and are supposed to have a limited shelf life before installation. They can be reformed by applying a slowing increasing dc and monitoring the leakage current. The failure of the receiver when the tuning dial always reached the same position each time was typical of a shorted tuning capacitor as Mr C showed us very clearly. If controlling the local oscillator, then hiss ceases to be heard from the speaker. It is indeed weird that this should happen inside a screened unit unless tampered with for some unknown reason because it had been correctly put back afterwards. Like Mr C I suspect the capacitor screws had not been tightened fully in the factory and over the years the capacitor plates moved as a result. Thank you Paul, you took me back many years.

[@McTroyd]

A loose screw... finally a problem I can troubleshoot and fix myself!! 😅 J/K Thanks for demystifying all this, Mr. Carlson!

[@JCWise-sf9ww]

Mr Carlson, your a good teacher of electronics restoration techniques, we learn something new with every video. I had done a 1929 Majestic 92 TRF radio restoration recently that had all 5 tuning condenser sections shorting out from rotor plates getting out of position from the cracking white metal that was used to mount them to the shaft. I was very lucky to fix that problem, by bending them. In the RCA CR-88 the shorting oscillator plates was an easy fix in your case.

[@KeritechElectronics]

A thing of beauty and a joy for ever - very elegantly repaired :)

[@davidbeard6851]

It's always great to see these old, sometimes battered boat-anchors spring to life at the hands of Mr Carlson, often better than they were originally. This one has highlighted how good the reception and audio quality were and how quiet the receivers were. Personally I find most modern commercial comms receivers quite harsh to listen to with noisy background and lacking in audio quality. That's undoubtedly the reason I have quite a few old tube receivers in my own shack, some of them home-brewed. Excellent and absorbing video, sound and picture quality just brilliant as always. Looking forward to the next episode.

[@davidolchewsky5365]

Always extremely nice and neat work, Mr. C. Being a perfectionist I always enjoy seeing such work. And I must apologize for my comment earlier about the 3 resistors. I hardly ever read the notes above, mainly due to watching on TV and why I didn't see them. I will look there in the future 4 sure; I actually thought you had done it for a reason. Anyway, sorry. Forgot to add that I finally got all the parts to build your much more accurate capacitor tester. I've got one of those Healthkit testers you showed in the video and don't trust it very much ever since I saw your capacitor tester design.

[@rgrabby2246]

Really like to see the procedures related to replacing the components. I'm new at restoringold readios so seeing exactly how things should be done is really helpful. Thanks for the great videos.

[@bofor3948]

Hats off to you for sharing your error. We can all make them and sharing helps others, hiding or ignoring them would only discredit the person who makes them. As one of my supervisors said to me when I made a drop off. The person who never makes a mistake, is a person who doesn't do anything. Nice work!

[@hullinstruments]

Absolutely! We are all capable of mistakes. And Accepting that is the only way to grow and keep progressing decade after decade. I worked around a few folks who we're slow to admit that fact... And that can lead to a dangerous situation really quick

[@jamieminton172]

New to the channel and now I have some binge watching to do. I have an affinity for all things old, as am I (I grew up with the tube kiosk at Sears). Primarily because the old school engineering was designed and built to be serviceable whereas modern engineering is designed to fail and be discarded and/or replaced. I have a very eclectic and practical skill set. Last week I was replacing a bath tub, repairing the sub-floor, rebuilding/servicing globe valves and troubleshooting a PTAC HVAC unit. Yesterday I did a break job on my neighbor's car (she is on a fixed income and auto shops are outrageously priced). Today, after a few more hours sleep, I have to repair an actuator for my van's heater. Tomorrow it could be a laptop or a network. I say this as preface to my question. . Your expertise is obvious and your narration/explanations are easy enough for a shade tree such as I to grasp. In two videos I have learned what a tub capacitor is and a couple of troubleshooting tips. . This may be only semantics or esthetics. You use the term "Restoration" while installing modern components. Something I would term as repair or upgrades. Why would you not or could you not rebuild the tub capacitors (if only installing new caps in the tub chassis)? That may be my esthetic OCD showing thru. Is it truly "Restoring" to an OEM condition if you were to replace a tube with a modern solid-state circuit? Out of sheer curiosity I want to now find out what is inside that tub chassis. I have a good idea, but the "Cat" has a few more lives to go. Can't wait to see the old RCA humming again. 😉

[@josephrogers5337]

I went through USN electronics school in 1961. I still remember the phrase we learn to know the color code which I will not repeat but not social correct for today but I sill remember ELI the iceman for inductance and capacitance. At that time we had 34 weeks of electronics and 2 weeks of Transistors, NO such thing as IC's then. KC to KHZ today, Micro Micro farad etc. Would love to find one of your restorations in the market place. I do have new modern stuff but I sill remember the old Motorola Push button bedside radio that my grandmother loved to listen to Gene Autry Show. I love your restorations on such high end gear of yesteryear.

[@MrCarlsonsLab]

Thanks for your comment Joseph!

[@peterwooldridge7285]

Well, I didn't understand any of that. But, still watched the entire video and found it fascinating. Thanks very much

[@MrCarlsonsLab]

Glad you enjoyed it!

[@jaredkusner1137]

Thank you. A fantastic lesson in repair and most of all, Trouble shooting. I also like how you take your time and practice neatness in how you do things. I learned so much today.

[@bwithrow011]

Professor Csrlson does it again. He should have several honorary doctorates!

[@phillipwalker8018]

I have enjoyed this series very much as I have a fascination for man-made machines, both mechanical and electronic. Having a very basic knowledge of electronics, I find your explanations very informative. What I love most is the amount of information and expertise you share with us. We start out looking at an electronic device sitting on your bench, but then you explain it's function, how the components work in service of the whole, and then you drill down and explain how those individual components may have changed over time. Some have manufacturing issues, some just get old or something happened to them while they were in service. It's like you see so much more than just that device sitting on your bench. And we are the benefactors of that. Thank you!!!

[@menetec42]

Excellent explanation. The inclusion of the schematic makes it really clear. I will look forward to building this for my workshop. Not quiet sure how the caps are matching the transformers. I'll need to do a little research on that.

[@denisdespins1127]

Man, I'm so glad you got a lot of room to just walk away with ease ! The other room had you bumping your elbows I'm sure !

[@book3100]

I've got to get one of these cool receivers. Seems like fun to slowly cruise back n forth to see what can be heard on different days.

[@Stevie_D]

EXCELLENT video - I enjoy you sharing both electronic and mechanical techniques ... even things that at first might look obvious, there is always something to be gained by watching how others (particularly Paul) handle it. AS ALWAYS, an interesting and fun learning experience! THANK YOU, Mr. Carlson!!!

[@cajuncoinhunter]

I like that ending where everything goes dim and then finally out, that reminds me of a show way back in the 60's ....

[@ianbutler1983]

These audio guys who buy old caps remind me of the guys who buy these monster speaker cables for hundreds of dollars.

[@rgmolpus]

I have two HP Audio Oscillators that I got cheap - sold as broken. I had to replace a few bad parts - easily found - but they refused to track properly. I couldn't align them. The problem was that someone (a tech on Friday afternoon?) had tweaked several of the slit cap plates, so the oscillator wandered all over the place as the warped plates made the frequency generated wander in a very non-linear way. Crazy problem. Crazy fix.

[@paulr8528]

I was wondering why the video disappeared while I was eating breakfast. Good to know it was an update!

[@julioramirez8582]

Description in layman terms, of what why, & how is exceptional. Makes me want to fix my old a/v receiver. Thanks for sharing your knowledge

[@jimw7ry]

1:00:35 When the left hand screw popped when you loosened it, you can clearly see the stator pop over and un-short! COOL!

[@ke4est]

Love the way you did that outro Paul!!

[@davearmstrong1932]

Thank you for your videos. You gave me several ideas why I can't get my tube radios working and showed me why I need to get soldering on my own probe right away,.

[@ronzek3207]

It would be interesting if any of the radio men that built this receiver are still around to see this and your updating.😃Thanks for sharing.

[@3ccdmike]

A sweet walk, thanks. You are very Canadian.

[@DaleDix]

The big new lab is great!

[@Greg-et2dp]

Mr Carlsons lab you are good at restoring vintage shortwave receivers and alignment of vintage shortwave receivers

[@woodywoodlstein9519]

Havnt watched in a few years on purpose so I can binge. Hahaaa. Been watching since near day 1. The only thing Mr C still doesn’t accept is that the L in solder is silent . Like sodder. Hahaaaa. Amazing video as usual. And Rob explains things as though you might be a first time viewer and know nothing about electronic components. Always explains foil or ground side of capacitors and why it’s so important. And why they changed and you literally need a tester to be sure.

[@hestheMaster]

The right kind of soldering iron for each part of the job. No fan of all those old Aerovox metal ( hermetically sealed ) paper in mineral oil capacitors. Mineral oil that has PCB's in it no less. They are old ,tired and shot. Great soldering skills demonstrated Mr. Carlson!

[@FelicianaDelacruz]

Amazing video Mr Carlson! I learned quite a bit from this one and look forward to the rest of this restoration.

[@-JZ-]

Mr. Carlson: Lyricist Neil Peart in the song, "The Spirit of Radio", might best describe the appreciation and general feeling I want to transmit to you about your work: "Invisible airwaves crackle with life/Bright antennae bristle with the energy/Emotional feedback on a timeless wavelength/Bearing a gift beyond price, almost free" THANK YOU for the masterful teaching and bearing the gift.

[@MrCarlsonsLab]

Thank You for your kind comment, and feedback too!

[@vincentstevens5048]

.. And Rush being a Canadian band might resonate (!) even more with Mr. Carlson.

[@Micotech1]

Its nice to see someone working in old stuff, we are a rare breed, however, you look quite young, and maybe your dad taught you your some test fixtures are quite old.

[@lauram5905]

1:00:00 I don't know if it's an intentional design but it's incredibly fascinating that the balance of torque between the two screws sets the position of those fingers. If it is intentional, I bet some poor fellow had to dial that in to perfection for that mil-spec performance. The moment you broke the left screw's tension and it jumped straight towards the middle again was quite an aha-moment from the camera's POV

[@markbatten5178]

Nice work on the caps! They look great. I did want to strangle you for not tightening the right side screw immediately though Lol. Thanks again for the great lesson on bathtub caps!!

[@welderfixer]

Paul, I can only imagine that your IQ must off the high side of the scale. I'm lucky to know what a resistor is. Thank you for sharing your vast knowledge and experience!

[@Drekkag]

Amazing video as usual. Funny how one little screw can mess up a radio. Loving this series and can't wait to see more of your fixing videos along with the great history you find with them. 73, ad0am

[@rubusroo68]

such a gorgeous receiver front is immaculate

[@jeffminnick5209]

Awesome to be sure!!! Loving this series, cant wait to see the Collins and the Racal

[@mbarf4210]

A good modification that is incredibly simple but a possible life saver - short contacts 4 and 5 on S23. This disables the TRANS mode leaving HT on the anodes, preventing the PSU being off load and climbing to over 500v. It still leaves the tx relay contacts available

[@DJRatAttack]

Your repair videos are so fascinating and entertaining and educational I love it thank you for making these

[@Joe-ir4cd]

Hi Paul, as always great lessons and videos !! I have about a dozen boat anchors here. And your instructions and methods are invaluable, in restoring these old pieces of technology ! So... Thanks for sharing your knowledge !!

[@MrCarlsonsLab]

You're welcome Joe!

[@terrym1065]

Totally awesome video, the quality of your videos are benchmark. Thanks Mr C for another in depth and thorough episode, I'm amazed that every one of these are absolutely above textbook perfect. This CR-88 and an appropriate antenna will certainly impress in it's restored to like new condition. Plenty of work to do and I'll be watching and learning. 73

[@peterh1386]

I cannot wait to see you align the 40MC/s filter in the Racal RA17!!!

[@rickoneill4343]

There it is! Welcome back.

[@InvinceableFrontRun]

Interesting to view and expanding knowledge.

[@mlkegates5857]

One word.....SUPERB !!!

[@keithmckenney4970]

I have a Marconi CSR5A that does the exact same thing. At one part of the tuning dial it goes completely dead. Now I am going to take a closer look at the capacitor plates!!

[@MrCarlsonsLab]

That, the oscillator tube, and the mixer tube are suspect.

[@keithmckenney4970]

@@MrCarlsonsLab Thanks!

[@whosonedphone]

That outer foil tester got me very excited!

[@duroxkilo]

this series is great. i found a vintage 150 Watts American Beauty 3138 at a garage sale, it's size intrigued me.... it takes like 10 min to get hot (~700F) but it melts a nice puddle like the one at 25:50 in less than 5sec. it makes chassis work a dream. the downside is it's size and weight, zero maneuverability :)

[@00Skyfox]

For that first capacitor block that got replaced, would it have been better to solder the new caps to a strip of copper that was then screwed down to the original mounting holes that held the old capacitor can? And I forget if I've asked before, can caps be adequately tested by hooking up a voltage source to them with an ammeter in line to measure if any microamps are passing through?

[@kirom4265]

Sir you are awesome! I want you to make a video on explain some fundamentals of how transmission and reception works on a simple rc car. I really want to learn how it works from an expert like you

[@qzepher]

Love the video Paul. I was impressed with the way you tested those bathtub capacitors. I also have heard guys say just leave them in the radio! I am in the process of restoring a Collins 32V2 transmitter and was debating whether to replace those bathtub capacitors in the modulator section of the transmitter. There are 4 of them, 2 connected in parallel. So I will plan on getting them out of there. I need to build some of your personal testing devices. Dave K9UX

[@Antony_Jenner]

Maybe someone though those screws where trimmers, you never know! Great video Paul.

[@LarryDeSilva64]

interesting that you are going to compare it to a BC348 receiver i rebuilt my BC348Q with minimal repair work and it has always worked fine. Someone had put a power supply in it and eliminated the dynamotor supply they originally came with. They Super Pro is another great receiver to test along side of it. You didn't name any Hallicrafters I have a Hallicrafters SX28A and it has worked flawlessly for me even though it was made in 1939. thanks for sharing Paul.

[@CrucialSpeaks]

that was great! and the end experience was awesome.

[@thedevilinthecircuit1414]

A simple way to test for a cap's outside foil is to solder two alligator clips to a guitar cable, clip the cap to it, plug into an amp and pinch the cap with finger and thumb. One orientation of the cap will be noisier than the other. The noisiest orientation has the outside foil connected to the center conductor (not the shield) of the guitar cable.

[@davidjernigan7576]

It would be interesting to see how they all compare to something like an icom IC-R8600 or similar. Knowing the icom has a lot more receive range, but just over the bands the older receivers cover.

[@reedreamer9518]

I would like to see this comparison too.

[@egomezmx65]

Another success Paul, great video as always; I noticed the ending is not like before, and dimming the lights is also cool.

[@MrCarlsonsLab]

Glad you enjoyed it!

[@utubejeffo]

Wow! Good finding that capacitor short killing the oscillator! My SP600 doing the same thing isn't that sharp though......as the plates turn, it just gently fades away to no oscillation. On a couple of the other bands, there's no problem at the same place on the dial. Puzzling. Anyhow, great work and as always, EDUCATIONAL! Thanks Mr. C.!

[@MikeFairman]

Thank you Mr Carlson it is great to see this RCA radio being restored to such a very high standard. I will be hopefully restoring my AR88D in the near future & rather than soldering the capacitors to the chassis I was thinking about using 2 ring terminals bolted in the original holes with a suitably bent length of fuse wire soldered between the two. I could then solder the capacitors to the fuse wire. It might be an easier & quicker option. Please let me know if you think it is a good idea or not ☺ Best wishes Mike

[@rdaws73]

Watching these vids is pretty comfy

[@EsotericArctos]

Just curious. Is there a reason you soldered directly to the Chasis, rather than using a lug abd one of the existing holes and original screws to connect up the three capacitors to replace that one capacitor block at the start? I am guessing the original capacitor would have primarily grounded via the screws holding it to the chasis

[@fordmustanggtish]

Thanks for the great video Paul! I'm really looking forward to every new installment of the grand receiver restoration series. By the way I love what you did with that Weller electrical soldering gun to solder capacitors to the chassis. You gave me a great idea.

[@jlucasound]

That loose screw was a "blessing in disguise"! We all now know about a rare but possible problem with the tuning cap! At least it wasn't a case of many, mangled, zig-zag bent fins left for you by an 11 year old! 😲🥴

[@_I_C.Q_I_]

Thank you Mr.Carlson. You keep me motivated!!!!

[@MrCarlsonsLab]

Glad to hear it Jordan!

[@jimmiemack1947]

Well, I guess all us radio hobbiest are doing re-capping wrong. We all should have one of those testers!

[@MrCarlsonsLab]

Time to build one Jimmie!

[@mikefinn2101]

Great Job Paul nice to watch this video glad you took the time on this one and patiently waiting till next video incredible very excited to see this very enjoyable.

[@DanielSmith-rw9ms]

Have you invented some sort of "time machine" also? Didn't even notice a sense of duration watching you. Great presentation, Thanks! I fairly certain I found that same vintage soldering iron new in box in my dad's things. Appears from the '50's

[@jerrymalone8370]

Can't wait to see what those canned capacitors look like inside.

[@fretlessfender]

Lovely, just lovely, planned to watch a couple of minutes... sat the whole thing out ofcourse... Nice work 👏 again!

[@Dyaxxis]

44:25 Gotta love the myths from the audio world constantly perpetuating themselves.

[@nathkrupa3463]

Great Video Mr Carlson Sir. Nice Information On Capacitors sir Please Were A Gloves On Soldering Thank You So Much For Sharing This Video Sir.❤👍👌

[@Tom-W7TMD]

Great video! Thanks so much!

[@Steve-GM0HUU]

👍Excellent series thank you and looking forward to next installment. I wonder if the variable capacitor had been adjusted with a "magic screwdriver".

[@MrCarlsonsLab]

I'm sure, it was probably Golden as well.

[@craigpennington1251]

Great video and learned so much from it. Nice radio too-very nice. Thanks for posting this series on the RCA CR-88.

[@jonathanreedpike]

Perhaps you could label the switches/controls on the projects you show/use/design, it might make them easier to understand.Your explanations are first rate and I think this would make them even more effective for us by allowing us to see settings on your instruments (kinda like subtitles).

[@izzzzzz6]

That screw could have just come loose in transit. Wow The Lab has become huge!

[@Greg-et2dp]

Mr Carlsons lab your vintage rca cr-88 communication receiver is cool 📻 😎 👌 👍

[@leetucker9938]

maybe you can find a number station when the radios are finished and I can listen to it on this channel. it will be easy for you because you are AWESOME

[@itsonlyme9938]

Looking forward to see how you are going to tackle the PSU smoothing caps. I am thinking to gut out the can on mine and then using vero board and clamp it between the box and chassis on my AR88D. I have taken my bath tub cap's apart and it looks like packed sardines in a tin can.

[@MrCarlsonsLab]

Careful with the oil, it's not too friendly.

[@itsonlyme9938]

@@MrCarlsonsLab Yes I know it is nasty stuff. G4LMZ

[@johnblystone8781]

Great video. Looking forward to more. Thanks Paul!

[@warplanner8852]

Paul, to clarify your points on flux cleanup, you specify lacquer thinner. Down here below the border, we go to Home Depot and the like and the lacquer thinner they sell here smells strangely like acetone. I surmise they are one in the same. In any case, I use acetone (sparingly and carefully) to clean up flux and it seems to work quite well. Wherein have I done wrong?

[@MrCarlsonsLab]

Thats kind of strange, they have two totally different odors. Acetone or lacquer thinner both work, same with alcohol.

[@warplanner8852]

@@MrCarlsonsLab actually, Paul, I believe you are correct. I remember "in the old days" there was a difference but recently I happened to have purchased a can of acetone and another of "lacquer thinner" at a big box store here in SoCal that smelled identically. I'll check this out. But, for the record, they all clean the flux off well. Acetone does a better job than alcohol I find because it evaporates more quickly and leaves little or no residue. Alcohol evaporates more slowly and, because of the water content, leaves a haze on PCBs. When building a kit or project, at the end, using a toothbrush and very lightly scrubbing the solder side leaves a bright, shiny piece of work.

[@donl1846]

Nice work Professor Carlson and I can't wait for the next video !