1946 Radio Receiver Teardown - The RCA CR-88!

[@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

[@Poppinwheeeeellllllieeeeez]

I legitimately thought you were going to do more hi-fi videos.

[@davids8449]

@@Poppinwheeeeellllllieeeeez Give the chap a chance...... Besides I have two RCA 88 one upstairs and one down...I have waiting for a instructional video like this for some time ( comment from England )

[@MrTalaue]

@@Poppinwheeeeellllllieeeeez This is much more interesting.

[@jimw7ry]

@@Poppinwheeeeellllllieeeeez There are lots of them on youtube. But not near the quality of production, camera shots and content.

[@robertmacdonald345]

Hello Watching this video as I write this, Just thought I would throw this out there, If in situations like this and Sliding heavy pieces out, Is it able to put a wooden/Plastic Dowel under it to help get it out, and Not Smashing your Fingers???

[@frankowalker4662]

When I was 10 or 11 I opened up an oil-filled capacitor in the garden. What a mess, there was oil everywhere and that patch of grass never looked the same after that. LOL.

[@maxjakobsen5526]

You always go out of your way to explain things, without time elapsing, but at a calm pace so that everyone can join in - it's just super professional - I love your fantastic videos.

[@MrCarlsonsLab]

I appreciate that!

[@MrMersh-ts7jl]

you're a treasure to students of the craft like myself. I thank you for everything here and on Patreon. I've learned and put into practice so much from your teachings.

[@MrCarlsonsLab]

Thank You for your kind feedback.

[@MrMersh-ts7jl]

​@@MrCarlsonsLabit's more than appropriate. I look forward to every video!

[@WackyT08]

This is what I like about your restoration videos, Paul! It's not all about Retrobrighting plastics. It's actually about electronics. 👍

[@barrieshepherd7694]

Thanks so much for bringing back memories from 50 years ago. I had the AR88 version, spent hours in front of it spinning that wonderful geared tuning knob - such a stable and brilliant receiver. HF aviation reception presented no problem with just a 60 foot length of wire to the fence post!. I did look inside and under the screening covers and wondered then about re-alignment but seeing all the twiddle points, and not having any test equipment, I resisted the temptation. I had a hairbrained plan to find a motor and appropriate gear to add so I could tune it from my bed - fortunately I held off that master plan! I regret selling it - but 8 years later I got more than I paid for it.

[@MrCarlsonsLab]

Thanks for sharing your story Barrie!

[@jimcandela9037]

I once had an AR-88. I got it from Ozona Bob, W5PYT (SK) about 30 years ago. Bob bought it sight unseen from the Yellow Sheets, and it arrived incomplete. It was missing an IF can, the phasing IF can, the mode switch, and the wiring harness was diked out! Bob gave it to me, and I promised I'd try to get it back in service. It took several years, but I did get it working quite well before Bob died in 1999. It actually HAD the alignment tool!! Some comments as I remember them. The AR-88 and CR-88 had a different IF frequency, but the IF can coils inside were identical. The only difference was the internal fixed capacitors (Mica I believe). One thing that floored me was the HV DC power supply with dual chokes and several oil capacitors for the filter. Any attempt to add more bass to the audio was offset with the C-L-C-L-C filter being excited into resonance from audio as low as 200hz. Jim Wd5JKO

[@MrCarlsonsLab]

Thanks for sharing your story Jim.

[@deplorable9022]

I thoroughly enjoy these videos. I have learned so much about safety and the importance of being aware of dangerous areas of a circuit containing leathal voltages. I must say that heaven forbid there were some sort of natural disaster like a cosmic radiation burst that knocked out all of our solid-state electronics or an EMP attack, the only electronic devices that would work would be vintage vacuum tube electronic devices. There are not many people alive today who have the knowledge and skillset to revamp and maintain this era of electronics. People like Mr. Carlson are very valuable and should be respected because of their willingness to help teach others to carry on their knowledge and keep it alive to new people interested in electronics.

[@JCWise-sf9ww]

You made one of the best decisions with your channel to keep your videos to about 1/2 hour and can pack a lot into that shorter time frame. A little bit at a time each week, I like it better this way. You cover every detail of what your working on, very nicely. 😀👍🥰

[@stevemercure902]

I am aware of 2 types of oil filled caps in the world. Ones that are leaking, and those who are about to start leaking. I'm very much enjoying your work on this beauty. 73 de W5EN

[@davidquerry8869]

Enjoying the new shop/format.

[@rotaxtwin]

That is a beautiful example, great to see it being massaged by someone of your abilities & experience.

[@nelsonjoaquim5918]

Ok Paul.... let's see what part3 shows us. Thanks for all your efforts! Cheers

[@terrym1065]

Simply amazing! The minds that created this absolutely incredible machine 80 yrs ago is nothing less than astonishing, using the available components at the time and engineering the mechanical processes is just magical. A lot of that was going on back then, Los Alamos, White Sands, Trinity Site... What's even more intriguing is how you know what these people were doing and thinking when building these things. I certainly hope that a bio is in the future sometime as you're pretty magical yourself Mr C.😉 73

[@MrCarlsonsLab]

Thanks for your kind words Terry!

[@glennbillings4621]

Paul, your lessons and knowledge helped me to get my 51-J4 working again. Thanks, keep it up! Glenn

[@paulcarlsen4088]

Look at the shine on the workbench! 👍

[@MrCarlsonsLab]

Thats a great name too! :^)

[@papaloongie]

Hi Paul. Great series. In downtown Copenhagen there is a museum known as the “post office museum “. I understand it has been relocated since, but they had a great display of a listening station and a number of disguised receivers and transmitters. The pride of the collection was an AR-88. It took a minute, (10-15 years) but I finally snagged one. It’s in decent condition, has the reverse reading meter, etc. These were often used in embassies, as well as collins 51js and others. Many thanks for all your efforts . Greetings from Montreal.

[@DrJaneLuciferian]

I love how detailed your step-by-step explanations are. It's helpful for someone who doesn't work with analog electronics, and it's quite endearing, Paul :^)

[@MrCarlsonsLab]

Glad you enjoyed it!

[@larrydee8859]

Thank you so much, Mr. Carlson, for another very informative vintage radio repair, troubleshooting video! Your lectures here, are very interesting, and pleasant to follow. (I always enjoyed working with vintage vacuum tube radios). Thanks again.

[@MrCarlsonsLab]

You are very welcome!

[@davids8449]

Some years ago I purchased a number of new old stock parts for my RCA AR88 all in their original wax paper a power transformer the large capacitor block to name but a few. Upon opening the large transformer from its wax paper which had not been opened since 1943 I found a copy of an American News paper which was used as packing the front page give an update of the war. ( Comment from England )

[@itsonlyme9938]

In 1975 I went down to a surplus shop here in the UK and purchased a new output transformer for my AR88 and that came in USA news paper about the war effort making bombers.

[@davids8449]

You were indeed lucky,. I also have a new output transformer for the same 88 upon opening the wax wrapping a few months ago there was some 1943 America straw used as packing

[@leearft8605]

The curse of making such a beautiful bench top Paul, a piece of Masonite also works well as a protective surface

[@luke8210]

Honestly, I feel like I'm in school every video. Thank you sir.

[@MrCarlsonsLab]

You are very welcome!

[@utubejeffo]

You cannot stress enough the value of shielding in these old receivers with all that dangling point-to-point wiring going on, and all those zillions of screws giving the whole thing not just bonding but physical integrity. This is a cold-war treasure and it's in great, good hands. Thank you!!

[@wa7215]

Speaking of ‘physical integrity’ of construction of electronic devices, just reminded me, that back in the early 1970’s as a then young and pimply faced Government ABC radio tech, I had the opportunity, to peer, into the innards, of a Wandel & Golterman Spectrum Analyser, that was being used for sweeping the response of some NEC low power, TV ‘Translator’ Transmitters, and their tower-mounted Antenna Arrays, that we were installing at that time, throughout remote and regional areas of Australia, and comparing the ‘physical’ construction of that device, to the construction of this 1940’s era RCA receiver, are a bit like comparing chalk, and cheese. The build quality, of the engineering in the W&G Analyser was, eye-opening, with every individual section of the circuit, being separately, fully compartmentalised, and with the entire, chassis, of the whole thing, being made from 1/3” (8mm) thick, Die-Cast, Aluminium, and with Teflon standoffs, and insulators, and gold-plated RF-coils, and contacts, used throughout it, everywhere. Needless to say, it weighed ‘a Ton’ (figuratively speaking) and was valued , at more, than my own, then, entire, annual salary. Needless to say, we treated it, ..reverently. 😉

[@DanielSmith-rw9ms]

Absolutely Wonderful Radio. I like how you can "parallel" park it on your new bench.

[@lektrikzz8763]

My AR88 has gradually lost performance and I was thinking of refreshing it this year... now I will wait for your hints to see all the things I might otherwise have missed! Many thanks.

[@DavidTipton101]

Fantastically impressive piece of equipment Paul. From the front it looks much younger than it is. Nice work as usual.

[@mauryfeskanich4523]

Hi Paul, I’ve found that using three or four dowels of appropriate size as rollers can be helpful to get a heavy chassis in and out of its cabinet.

[@davidportch8837]

another wonderful restoration Paul...loving this series...

[@3ccdmike]

That set has great aesthetics.

[@2006chame]

just wanna say thank you for sharing these incredible videos showing deep knowledge and tricks to repair

[@richards200]

I know absolutely zero about radios, but I can see that this one is a work of art and was designed / built by people who had some pride in their work

[@randypullman1155]

Another exciting video. Personally im here for the replacement of near 100 yr old components and the expertise placement of 2023 components. Cheers!

[@LarryDeSilva64]

with the wire looms and the way that is constructed it looks just as good as a piece of Collins Gear. Everything has a place and is separated from each stage to keep the radio from just taking off from RF. Very nice look inside the radio Paul. Thanks.

[@nathkrupa3463]

You are awesome Mr Carlson sir great. Nice and beautiful model sir thanks for sharing another video. 👍

[@Greg-et2dp]

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

[@bob9483]

Time to slow down and enjoy some time at the bench with Mr Carlson…

[@jeffclark2725]

Well said, i usually save these videos to watch on sunday mornings, that thing does look heavy, and with the components getting removed that case probobly gets really flexible, he is a real artist

[@coryengel]

The sound is better in the new lab. It’s less dead-we can hear just enough room echo to make it sound natural and lifelike.

[@Greg-et2dp]

Mr Carlsons lab you RCA RECEIVER CR - 88 from 1946 is cool 😎 👌 👍

[@donl1846]

For something that old it is in remarkable condition inside and out. Thank you Professor Carlson for taking us along with this project.

[@JimmytheCow2000]

That alignment is going to be amazing! Thank you for the videos, I love the new bench, love that you read my comment. Thank you for teaching me and showing me so much. Thank you

[@MrCarlsonsLab]

You are so welcome!

[@tomstrum6259]

What a splendid Special receiver that's in relatively great condition !! .....Radios that Large & heavy needs heav6 duty Side grip handles !!

[@hestheMaster]

Impresively well built receiver! Thanks for the tour "under the hood" so to speak Paul . Loved the peek inside and detailing calm demeanor with what you will do to it. Can't wait until part 3.

[@RckyMtneer]

Cool. There were a number of versions of this radio. I have an AR-88 as well as an SC-88.

[@iskandertime747]

Great series Paul!

[@flicewatter]

Beautiful piece of equipment...

[@MikeFairman]

Thank you so much Mr Carlson! I have a RCA AD88D which I bought in the early 1980's. I have not used it for a long time & I have been waiting for you to restore one so I could attempt to do mine. I was not sure on whether or not to replace the oil filled caps as I had heard they would be ok. I will definitely replace mine now. My AR88D has been modified at some point & a ECC83 has been added. Not sure why but hopefully I will be able to figure it out 😄 I look forward to your next videos. Thanks again 👍

[@MrCarlsonsLab]

Hi Mike. The ECC83 or 12AX7 is probably a product detector. A real common modification way back when.

[@alexisstarsmith1477]

Bizarre funny - went to pick up my tablet as you pulled up the tuning capacitor lid, swear my tablet felt the same 😂

[@liamtheinventor1522]

From what I have learned oil caps like the ones in you video could contain PCBs or polychlorinated biphenyls which are hazardous. As a side note PCBs are very hard to dispose of because they are resistant to acids, electricity and fire.

[@Greg-et2dp]

Mr Carlsons lab I can't wait when it is done the RCA RECEIVER

[@jamespaterson7597]

very interesting mr carlson thank you

[@MrCarlsonsLab]

You are very welcome

[@mikefinn2101]

Wow It was so nice this morning to watch this long awaited next part of a very rare expensive radio restoration great to finally see the insides and see it restoration process begin, looking forward to the next video. great job too Paul. Be waiting for next videos Love watching makes my day 73s wb7qxu

[@nickademuss42]

That radio does not have built in obsolescence, what a tank!

[@thormusique]

What a wonderful project! I'm really enjoying this, cheers!

[@chansetwo]

Many years ago, when I received my AR-88 from a friend in the UK, I was advised not to change the bathtub caps - even if they are leaking oil. I'm glad I listened to that advice. To this day, my AR-88 works flawlessly with nearly all original parts - including tubes. The bathtub caps I have checked test within original tolerance, under voltage. If the caps leak oil, I would rather clean and seal them, rather than shotgun them. The oil is probably toxic, but manageable if you're consciousness. Just don't eat it or smoke it,

[@peteshulver9221]

Another splendid video Paul I can’t wait for the next stage 😀

[@TheBudliner]

Great info, another vintage gem brought back to the world by a great technician. Wish I was in a better place in life to splurge on your patrion. I’m sitting on no less than a hundred cbs short wave receivers testers and you have a great ability to get to the gist of these problems. It’s the the 4 year old that sits at a piano and it’s amazing, and I can study for years and just can’t get it. But I won’t give up. Thanks for sharing all your knowledge ❤

[@2169scs]

Excellent

[@MrCarlsonsLab]

Thanks!

[@davelowets]

That's one hell of a receiver from that time period... 👌

[@McTroyd]

Looks like you could use a gantry with a camera mount over the bench. Perhaps another Patreon invention? Really cool receiver. Love that gearing up front.

[@mortwin6054]

Loving this keep up the good work

[@IanScottJohnston]

For heavy equipment like this I have a large Lazy Susan, makes moving it around a lot easier.

[@levi2bear]

You are such a gifted instructor. I really have learned so much from you thanks again.

[@MrCarlsonsLab]

You are so welcome!

[@mchavez56]

Foam Core: you can get black or white or "kraft brown" and also non-acidic for museum quality work: there is also some 1/2 inch stuff with various names one of which was "gaterboard"

[@Alexelectricalengineering]

Nice as always, the capacitors are filled with polychlorinated biphenyl oil's, if I am right, I was see them in old motor run capacitors often, the smell is really unique

[@freddybee4029]

This was the first shortwave receiver that I owned back in 1976

[@edwatts9890]

I'm five seconds in, and I have to ask: New microphone? New audio processor? New studio? New larynx? The sound is much more "lively" than in the past, and that is obvious on my phone!

[@W1RMD]

Great job! This is giving me incentive to get my Johnson Invader 2000 back on the air with the Heathkit SB 300 RX. I helped support the Ukraine and bought some 1N16 nixie tubes to build a cool frequency like the one you built back in 2016. I love seeing the old transmitters and receivers that you restore on here. Great to see you back in "full operation" again. Can't wait for the next Patreon project as well. Best regards!

[@trip5003]

Awesome vid . If you lift the case a bit and slide your protection mat under the feet of the case you can then slide the inside component right out onto the matt without any concern of wrecking your table top . It will hold the mat in place . 👍

[@richpelto248]

Excellent 😊❗

[@JamesFord-mo7vg]

Nice radio love the old stuff over modern

[@bernhardbjornsen7155]

I learned electronics at Ft Devens working on the R390

[@sootydave1]

A lovely radio soon to be back to it's glory. I have the AR 88LF radio that I soon will be restoring, Mine still has the original tools in the clips.😀

[@Greg-et2dp]

Mr Carlsons the RCA cr-88 receiver is will built 💪 👌 ♥️ 😎 👍

[@lindonprice2482]

I think that mrw stands for Montreal radio works, the original assembler of that radio.

[@jimgiordano8218]

the board is called "Foam Core" perfect for what you are using it for.

[@monfrig6959]

Your a GENIUS !!!

[@Satchmoeddie]

I am thinking of repurposing an old air hockey table for the part of the bench where all the stuff I work on goes. Variable fan pressure and I can balance it between moving heavy stuff around with one finger and making all of my small parts fly away.

[@georgekoerner6591]

Great job and information!

[@billysharp3388]

Never a disappointment watching you do what you do so well.

[@aserta]

I'll be honest. Something made me expect some sort of carnage when the back was shown in the previous episode... but this ain't bad. It's actually quite a bit cleaner than other examples i've seen online, cleaner than other other-than-civilian equipment i've seen. What a great little capsule.

[@HectorLopez-jw2ke]

Hello. Please make a tour explaning every equipment on the back.

[@renowden2010]

I thought mine was clean but yours looks like it came off the factory floor. At 11:40 in the video you will see at the back of the shot on the side of the chassis there is a little spring clip. That is where there should be an Allen key (2mm I think) intended to remove the front panel knobs. As usual it is missing.

[@dashcamandy2242]

I was wondering what that little spring clip was for...

[@tomk1tl39]

We had these AR-88's when I worked as a CW op @ WPA/Port Arthur TX RCA coastal station....they were excellent on the 4/6/8MCs band but were so-so on t he upper HF frequencies.......we used 600Ω 'cans' but installed a step down xfmr 600:8 Ω so I could use a regular headset to keep the external noise to a minimum...it definitely was not a quiet room as we were monitoring 500KCs while at the operating position(s).

[@MrCarlsonsLab]

Thanks for sharing your story Tom!

[@woodsprout]

20:17 ~ Hi Mr. Carlson. Can you please tell me what this goose neck lamp is called? I have been looking for one of these with this shape. Thank you.

[@Calamity_Jack]

Just a minor note that the black paper-faced foam board is commonly referred to foamcore. It's typically used as rigid backing for photographs and picture framing, but it has other uses (as you've shown). Very interesting rebuild, looking forward to the next ones!

[@robozstarrr8930]

i currently place the black foam bds on my ( sun-facing ) windows to passively help keep my place a little warmer . . . i'll switch to white ones come summer!

[@gandalf87264]

It looks like a fantastic car radio. It will make my center console look very impressive. I will try to keep my toes out of it.

[@johnnorton6085]

I'm very interested in how you hook up the 50-ohm input of the spectrum analyzer. Thanks for doing these. I love your videos.

[@MrCarlsonsLab]

The input (one of them) of my spectrum analyzer is 1M Ohm. It's an HP 3585B. I use this input for these alignments.

[@leonardpeters3266]

Just a beautiful piece of engineering. Wow.

[@MyltonEE]

Nice video, very interesting. The only thing missing is the sound of your old tube mike :)

[@solarbirdyz]

I'm very much looking forward to the part where you clean and lubricate the gearing and tuning capacitors. I've been putting a junked EICO 379 frequency generator back into working order (so very many parts have been broken, including physical components - it was very dead) and while my cleaning and lubrication so far has done a lot, I think there's a fair bit more room for improvement in the tuning gears. The black foam material is usually called formcore, by the way. Because it's paperboard, but with a core of foam.

[@olegrovnyakov8474]

Hi Paul, thanks for the new episode! My tiny amount of scepticism for this 32-minutes video: 5 minutes of intro; 6 minutes of how to open the case and how to move it around a table carefully; 5 minutes of outro and about what you're going to do for the next episode. (Not to offend you! :)

[@MrCarlsonsLab]

My advice to you: Read the comments from people that own these receivers (AR-88's included,) see if they find these videos beneficial.

[@olegrovnyakov8474]

@@MrCarlsonsLab I don't deny it's beneficial for viewers. Usefulness and conciseness are different things. It's about information/time ratio: this episode could be squeezed in half without loss of helpful information.

[@faxcapper]

Epic!!!

[@robschertler8099]

Paul, I have a prediction. I do think that you will end up doing those oil capacitor rebuilds. After all, you did that wild 'Transformer Repair {Depotting}' episode 4 years ago. These should be easier than that, and they will look SO FACTORY when completed. That can be a whole episode by itself.

[@dougtaylor7724]

What weighs more? The radio or the alignment manual?

[@derekloudon8731]

I’m really enjoying the shorter videos that take you through the various stages of restoration. A long ‘all in one’ session could be difficult to follow.

[@christophermarshall5765]

A long time ago, I was a CB radio operator. Needed a licence at the time. A friend of mine showed me a book he had which covered repairing CB radios. One question was: " Your radio starts smoking. What is it you do next?" My friend wrote: " Turn it off, some b@#!%^&'s got a big linear amplifier!!" I had to chuckle. Have you seen Yaesu's FT-710 radio? They are good. I bought one a few days ago. Just waiting for conditions to improve.

[@ariedekker7350]

Thanks Mr. C. from pe1krx

[@itsonlyme9938]

My Ar88D came with as rare as hens teeth special tools for adjusting the plunger trimer caps which are clipped to the tuning capacitor box.

[@MrCarlsonsLab]

You are very lucky!

[@itsonlyme9938]

@@MrCarlsonsLab My AR88D is date stamped on the tuning gear drive mech 1943 by the navy and those trim tools must have been supplied with the set from the factory all those years ago.

[@patprop74]

10:00 perhaps a small overhead crane would have been handy hahaha, you know something was made to last when it weights as much as 20 modern radios

[@KingLoopie1]

Foam board... Makes great home built rc aircraft!