1946 Secret Listening Post Radio Receiver - Will it Work? Lets Restore it - 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

[@jamesengelstad3849]

Tnx! The first thing I noticed was the right inside panel has been pried out. Ouch! I have I Collins 75a4 that I have used for years for comms all over the world. Any thoughts? Jim WA7JNF

[@AnonymousSquirrel123]

*My biggest question is where did you find this thing? I've been looking for an 88 for years - nothing. Where did this come from?*

[@matthewblackwood4704]

Hey Mr. Carlson. I have an old vacuum tube case FULL of vintage tubes still in their box, is that something you would be interested in? It's been sitting in my father in laws garage since before I was born. There is a vintage oscilloscope and some other old electronics equipment also.

[@jamesbryan3917]

A

[@markvolstad9380]

@@AnonymousSquirrel123 I've seen a couple at the Dayton Hamvention flea market, but they were in pretty rough shape.

[@restorerestoration4705]

Great to see the master at work once again..

[@freemantransmission]

In the 70’s as a young teenager, I bought one of these from a used surplus electronics shop on Craig St. In Montreal. The shop owner “let me have it” for $100, a lot of money for me in those days. I can still remember the cab driver’s surprise at the weight when we loaded it his trunk. I lugged it a few steps at a time up to my mom’s apartment. I think they weigh in at just about 100 lbs. Countless hours of fun tuning in the world…🙂

[@bruceclaxton5721]

Dear Mr Carlson, first of all let me tell you that I am a full Patreon member. I have carefully followed every one of these KZbin videos you did on the RCA CR-88, the reason being that I purchased a CR-91A out of Canada and had intentions of rebuilding it completely, I have a fellow Canadian ham in Northern Ontario, who has completed 4-5 of these over the years and is helping me along. While I was waiting for the radio to arrive, I had an idea to build a simple rotator, that would allow 360 degree rotation of these to work on them. I proofed it in Solid Works with 3D models and made some simple drawings and proceeded to build it just before the radio arrived. I was absolutely thrilled with the simplicity and safety of my device and my ham friend in Ontario, thought it was amazing. It is built of 3/4" plywood and a couple of 20" lengths of 2 x 2( 1-1/2) popular . Total cost on this was about $60-$75 and if you have the plywood would be next to nothing . It sits on a 22 x 24 base with felt sliders on the bottom of it, so it can be turned around. I have been using in for the last couple of weeks, while re-capping and working on the transmission. I did some balance work to find the axis of rotation and hit it right on in the first try. It does involve drilling 2- 1/2" holes in the triangular side frames, to install the axis bolts, which are a couple of 1/2-16 x 3" long hex bolts.How can I share this with other members, as I think they would love the ability to rotate this whole chassis 360 degrees with one finger. Thank You Bruce KO4UHL

[@PDZ1122]

I have zero idea of what he's talking about, but it's really interesting!

[@glennbailey6505]

I am a retired industrial engineer and view Mr. Carlson’s videos from time to time with the same enthusiasm as he has. I cannot get enough of this stuff even in my retirement years! I have separately restored three AR’s 88’s over the past ten years and these are remarkable receivers for what they were intended. After restoration, RF/IF/OSC alignment can be a bit challenging, especially if the alignment is way off before beginning, but once properly aligned there is nothing better to just sit back and listen to this marvel of 1940’s technologies. My hat is off to you Mr. Carlson for doing what you do and the professionalism you exhibit. Keep up the excellent work.

[@MrCarlsonsLab]

Thanks for your kind comment Glenn!

[@jeffclark2725]

Well said, did these machines have tape or some other recording devices built in?

[@glennbailey6505]

@@jeffclark2725 I am not aware of any internal recording capabilities of the AR’s or CR’s or at least for the one’s I restored did not have any internal recording capabilities. I would assume where most AR’S were stationed for surveillance during WWII audio recording capabilities were handled with an external wire recorder and later tape recording.

[@jeffclark2725]

@glennbailey6505 ok,I wasn't sure, was a thought, when I was hearing about it being a really great radio,reciver,and all it was capable of, an external recorder was the way to go

[@itsonlyme9938]

@@jeffclark2725 No

[@MrPatdeeee]

Kind Sir Paul, I heard you say "Butchered" and that brought back nostalgia for yrs ago; when I was a RCA Service Co, technician and Instructor. Now we ONLY fixed RCA electronics. But "RCA Victor" sold them to any one. This caused a big problem. IE: Many technicians from other Co's were not trained well; and they almost always butchered, when trying to fix it. Then they would fight with RCA Service Co; to get it right for FREE. And I can't tell you how many Radios, and TV's I had; that were butchered horribly. And RCA Victor's "Distributors"; would force us to fix it. Yet with NO money. IE: RCA Victor wanted to keep their high. And many a time; the Radio or TV was so bad, it would take weeks to fix it right. Then the distributors would race cane, that we didn't do it earlier. Believe it or not. I am so pleased Paul that you do it right.❤

[@vacuumfireradio253]

There are so many cheap AR88 receivers in the UK I hope UK viewers are encouraged and motivated by this series to buy one and have a go. If you have room for just one vintage receiver in the shack this is the one to get. I have over 30 different models from Collins to RCA. Excellent work. Thank you.

[@jessemontano762]

Im a simple man.. I see a new video from prof Carlson, I click. 👍

[@mnpd3]

I can clearly remember switching the receiver and transmitter in the older days. Yep, I'm that old.

[@jessebimbo6361]

Enjoy your channel it’s the best I am a radio nut

[@djosbun]

I don’t do this type of work but I can honestly say that this channel is one of the 10 best on KZbin. The attention to detail, the technical information and the presentation is SUPERB.

[@johnwest7993]

I've done this type of work for 60 years, and I agree with you. I still wonder how someone substantially younger than I knows so much more about old radios.

[@djosbun]

@@johnwest7993 Sixty years……God bless you! You made a three hour video talking about electronics history that you’ve witnessed I’d watch ever second of it.

[@MrCarlsonsLab]

Thanks for your kind comments!

[@DanielSmith-rw9ms]

Agreed!

[@Steve-GM0HUU]

Those other 9 channels must be very good if they can be compared with Mr Carlson's. 😄.

[@erin19030]

Very interesting introduction. Thanks for the refresher course.

[@jamesstephenpeyton3305]

I used similar Spillsbury-Tindal radios in the arctic during the 60’s.

[@nickwallette6201]

Seeing the inside of a point-to-point wired device fills me with a sense of existential dread. I know there's a lot of love for them among electronics enthusiasts, but, IMO, _bless_ the printed circuit board.

[@brianwood5220]

Great video Paul and thanks for sharing.

[@deeparks3112]

Thanks. In our Secret Listening Post the workhorse receivers were RCA and Collins R390A's - and indeed they were built to take a beating. Each intercept position had two receivers so you could dial in both sides of a conversation. These days everything is automated on the intercept side, and extremely little "live" intercept done. Fun times.

[@TonyLing]

Great to see the master at work once again.

[@MrCarlsonsLab]

Thank you kindly.

[@tomwaller6893]

In the 1960s, I trained as a Special Radio officer in 224 Signal Squadron Loubourgh near Leicester. Many of the Set Room positions were AR88 receivers. What memories.

[@5cloudwalker]

I just realized why I find resurrecting really old radios 📻 more engaging.. they had character. The insides of your radio receivers are interesting but the outside they are all just grey boxes with knobs and dials… nostalgic wise I imagine families huddled around these old wooden radio cabinets with their colourful dials knobs etc. guess it’s just the romantic part of me to see such things resurrected 😊

[@I-Libertine]

Bingo. Perfectly said.

[@ml.2770]

I don't believe you that you 'just realized'.

[@higgme1ster]

That gizmo reminds me of our Collins R390 radios we had in the USAF Tech Control facilities to monitor our HF frequencies and tune up FSK radioteletype signals. I loved that thing. Oh yes, everything we did was Top Secret too. Our Air Force Specialty was discontinued years ago when Digital Communications made us obsolete.

[@edwatts9890]

I just completed my Icom X75 collection. They will all be receiving new electrolytic capacitors; and the IC-375A needs a new frequency encoder, which I found for $75.00. So, I have IC-275H (2m), IC-375A (1.25m), IC-475H (70cm), IC-575 (10m and 6m), and IC-1275 (23cm). I also have the Log Cabin Republican unicorn TV-1275 ATV modulator for the -1275. My interest in amateur radio has suddenly been rekindled. I am also "restifying" a Hallicrafters SX-42 with gold-plated tube sockets, a chrome-plated chassis à la E.H. Scott, precision polyester capacitors, new resistors, and so on. Thank you, Mister Carlson, for all that you do. Your efforts and time are not wasted. Would that I could live next door. Ed, KI6DCB

[@danielfoster2788]

Mr. Carlson‘s lab is the very best! Seriously, he is direct, methodical , no politics, an avid learner and a profound teacher. You won’t escape reality by him and his teachings a purified reality. In my lifetime? I want so much to meet with those of Mr. Carlson’s kind influential pro-meanor ;-)

[@DIlic-iz9tx]

_The radio receiver is first class. There are no such quality radio receivers today._

[@rodleger7132]

Love the new workbench areas. Great to see the vacuum equipment being brought back into service.

[@martinsiebert1368]

I restored an Eddystone Model 730/A1: It's the best receiver in my shack. Very similar design in circuits and functions with your CR-88. These kinds of radios were built without any compromises in electrics and mechanics. The complete opposite of today's disposable goods.

[@aserta]

You can also use a welcome mat. The kind that has a rubber substrate and an office carpet top. Flip it upside down, rubber up, and you'll be able to slide stuff down on it because the dense carpet is almost like a cushion of air. It will also never slide on the rubber. Heaviest stuff i've moved using this method is a cast iron radiator on a parquet floor.

[@crackthefoundation_]

Hm, thanks i'll remember this!

[@zulumax1]

I buy the door mats from the dollar store for this purpose.

[@2tallB]

This is why I always scan the comments on good videos. You pick up all kinds of info. [thumbs up]

[@luminousfractal420]

We used to use old carpet on site when we were stripping houses, pretty good until it tears 🤣 have to say it was a lot easier sliding a carpet around than it was to fill and tip a wheelbarrow 3x over.

[@thedevilinthecircuit1414]

Another option is a foot mat designed for automobiles. These are available in auto parts shops. The type designed for the rear seating area are usually rectangular and 12" x 14" size or so.

[@Go4Corvette]

I use a rubber antistatic mat with wax paper under it so it easily slides around my bench. Great video, thank you, Mike

[@sEngineer-il8im]

This inspired me to start restoring my Hallicrafter Sky champion 1939 Receiver!

[@markshogan2642]

I’ve always loved old tube transmitters and receivers. Back when my cousin James and I were about thirteen, we Jerry rigged a walkie-talkie as a transmitter up with an old Ham radio receiver. We timed the receiver to the broadcast band and tried to transmit. I think we managed to partially jam a local AM radio stations signal. I’ve always wondered if the FCC was trying to find us. We were trying to transmit for about twenty to thirty minutes. It’s also a miracle we didn’t get electrocuted with the high voltage in that receiver. I wish I had it today. It was old enough to have had a copper chassis.

[@maryrafuse3851]

Mr. Carlson is a Canadian treasure. Such a wonderful thinker & communicator. All of this in a great engineer. So much of the code gathered with this type of radio was fed into places like Bletchley Park. The "Y" stations gathered intel under the most unusual of conditions, mostly from within what was then the British Empire. Mr. Carlson is working with living history embodied in this radio and others like it. The RCA AR-88's were amazing along with the HRO's treasured by the "Y" Service.

[@alexwild4350]

Yes but the Y service was alot of school boys too young for active service though some were taken in despite this, and those operating at home used regen receivers they built themselves. The spirit of the times.

[@maryrafuse3851]

@@alexwild4350 That was part of the Y service which also operated secretly at a very professional level.

[@STR82DVD]

I was, once upon a time, a Rad Op in another life. I'm pretty familiar with those particular broadcasts and I still DX the odd rogue signal on my Tecsun PL-368 SSB or my Eton Elite Executive SSB. 73 Mr. Carlson.

[@matushoffej]

Mr. Carlson is a great person, he cares about his videos and always takes the effort to explain everything nicely. Thank you very much for that. Regarding the last video regarding the comments, I have a question for Mr.Carslon. Is there a chance that sometime in the future you will also design some circuits for amateur radio amateurs? For example some simple wobbler that could be connected to an oscilloscope and set filters with it, some simple VF circuits or maybe even some parts of radio amateur devices. In any case, I wish you all the best from Slovakia.

[@rjpmcmillan]

My mother used these radios during WWII when she was a "Y" station operator at RAF Chicksands. When I was 10 -12, she taught me "Morse code". At 30 WPM, she was just ticking over, I never got anywhere near that.

[@johnbobbitt6872]

I had an AR-88 in my bedroom as a kid in the early 50s. My dad had bunches of these on Guam for diversity reception of teletype in 1944-1945.

[@Nonsense62365]

THIS IS VERY COOL! AWESOME

[@greggorr314]

TEMPEST without the teapot! Cable companies used to sniff out "borrowed" cable boxes this way.

[@kristereriksson3086]

❤️❤️ Had one for over 35 years, bought it around 1978 100% original, working, newer touched or repaired. Even had trimmer tools inside. It have now a home at a private collector. Have been told by previous owner (SK) it was only 2 samples in Sweden, CR-88 much more common. Dont know if that is true. Many memories when i was a very active DXer. Now hamradio but still listening.

[@OldePhart]

Yay, back on the bench !!!

[@alanambrose2204]

LSW Jim. Used these over 60 years ago on a Y station. Always a joy to use. Always received AFN Tangier better than British sets. Ha ha.

[@tonip...tarraco]

This is a really cool radio... Good video... Greetings from Spain ( Tarragona)...

[@CuriousMarc]

It’s a beauty!

[@MrCarlsonsLab]

Thanks Marc!

[@Greg-et2dp]

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

[@utubejeffo]

Great! The receive series is on again....I'll be hanging on this very attentively. I have a SP600 that just fails to work in segments of certain bands. 6C4 oscillator tube just gently fades gradually out and stops oscillating as you tune across those segments. Puzzling. Got tired of fooling with it, so looking forward to the SP600 episodes. It's also an acrobatic flashlight nightmare to align that turret inside! A cold-war chunk of superb Hammarlund engineering and a two-man carry!! I put it on a turntable to get at it while it frustrated me. Keep on keeping on, Mr. C. Thank you!! 73, Jeff

[@brianveitenheimer4492]

I have a CR-91 A and it’s been my main SWL receiver for years. It weighs 109lbs and is the quietest receiver I’ve ever heard. Very selective and a joy to use.

[@carlmclelland7624]

VERY interesting show, and you earned my subscription. Let's see, I've got a couple solid state rigs in the shop, and prefer to use my Yaesu FTdx1200 for it's simplicity. That said, when I feel nostalgic, I've got a couple Swan 350s and a Swan 500, but the 'crown jewel' in the shack is my Drake 'C' series system, along with a Drake L-4 amp. I look forward to watching your channel and learning new things.... Carl, KF7GJO I forgot to add; I use foam shop flooring to set the rigs on so I don't mar the benchtop, and, a muffin pan to hold nuts, bolts, screws, and all the other things that tend to get lost when you 'go inside the boxes'....

[@WeWereYoungandCrazy]

When I operated novice ham radio station, WN5DVY, in 1969 this model was my receiver. I still have it. Hasn't been turned on since 1970ish. The transmitter I used was a Heathkit (what else) DX-60. I still have it. Those were the days.

[@raymondlau6507]

Mr Carlson's lab always looks so nice, neat and organized. When I try a project it looks like a crazy haphazard mess of tools and parts all strewn about. I want to be more like Mr Carlson.

[@michaelmoore7975]

Yup. A model of organized work ethic, occupation, environment, appearance and life in general.

[@elkabong6429]

You and I both! Maybe in my next life?

[@hernerweisenberg7052]

Only the genius can navigate chaos with success, simple folk like most of us need a place for everything or we forget where we put it ;D

[@LawyerCalhoun1]

I always wanted an AR-88, but never saw one for sale at a hamfest. About 12 years ago, at the day of set up at Dayton, I saw someone offering a CR-91, a variant of the AR-88. As I was getting up the courage to use my negotiation skills, a friend of the seller swoops down and buys it from under my nose.

[@timgreen6547]

Just started this video . I own 4 of these . 2 ar-88lf and 2 cr-88a's . Almost all of them I have had to replace the filter caps . Warning they are full pf PCB oil and most of them are already leaking and are soaking the wire harness . By far my favorite receiver . I also have the r-390 sp-600 75a4 , nc-300 nc-303 etc etc etc etc and I always come back to the RCA workhorse .

[@davidquerry8869]

I'm not really into electronics, but yet, I still totally enjoy your channel.

[@careycraig4360]

Great Video! This CR-88 Radio has special meaning for me. My Father was in the R.C.A.F as an Electronics Communication Tech. from 1948-1968. This CR-88 Radio was exactly the type of equipment he would have worked on. In 1968 the CND Military put a lot of these Radio up for SURPLUS. You could buy at that time a fully Crated Radio Surplus from a Military Surplus Store for about $50CND. I had one in my home at that time,, in fact I had two different models, a CR-91 and a CR-91A. The only difference I can remember between them was one had the BROADCAST BAND and the other received frequencies BELOW the BROADCAST BAND. These indeed are Very Sensitive and Capable Receivers despite there age. The Very Best designs and components were used in their construction. The Broadcast Band ran from about 540Khz to 1800KHZ. I had a long wire antenna attached to my radio and I could receive and identify Broadcast Stations at every 10KHZ interval on that Band 540-550-560-570 ect ect on and on up to 1800KHZ AMAZING! of course the AM Band was more popular back then and at night you could listen to Stations over a 1000 miles away like they were right in your own neighbourhood. My Father took me on several occassions to his work site. The Military had Receiving sites that had HUGE ANTENNA FARMS. in those days back in the 60's and not far from the Receiving Sites would be a Transmiting Site with it's own Huge Antenna Farm. All Very interesting to a young fellow like me at the time. I am going to follow you on your restoration project with this CR-88. You have a GREAT CHANNEL going here. !!!

[@edyoung6573]

Man I miss those radios!! I had a hammarlund HQ 180C (with clock) I use to listen to shortwave radio and still have all my QSL cards, my favorite and most memorable is from Arni Coro from Radio Cuba got it in the 80's. He read my report on the Air!! Had to sell it when my wife and down sized.

[@faxcapper]

I am SO going to enjoy this restoration!!!!

[@leradiodigiorgio-iu1edh]

Beautiful receiver, my cousin owns one and I've been courting him for a long time to get it, I've had the opportunity to listen to it and it's really very performing In Italy it is rarely seen in radio or amateur radio markets

[@georgekoerner6591]

Mr. Carlson your knowledge is amazing!

[@waltneitzel4950]

I have a surplus Belmont Radio BC 348 aircraft receiver (Aluminum chassis. ) from about 1942 That still sort of works, and has some cobbled up modifications. It was originally a dynamotor model but I converted it to an external power supply. I also have to use an external amplifier for the sound as the audio tube stage doesn't work. In the past I would listen to WWV at 10 mhz to set my clocks but of course now days every cell phone can tell time to the second. I also have a lot of information such as the schematics for just about every different BC 348 versions that was made. I once had the portable version of the BC 348 too but salvaged the tubes and some parts off of it and tossed it, as it was too heavy to lug around in my Air Force transfers. The aircraft version is heavy too but since it is mostly aluminum it is still possible to move around fairly easily. The RCA CR-88 looks like a pretty neat receiver and I envy you. I enjoyed you video and looking at your electronics lab. At a young age in the USAF I learned aircraft and ground Radar systems.

[@MrCarlsonsLab]

Thanks for sharing your story Walt!

[@waltneitzel4950]

@@MrCarlsonsLab You are welcome. Good luck in restoring the CR-88 receiver. It seems there a lot of surplus BC 348"s still available but I didn't see any CR-88's. As well made as they look, maybe people are hanging on to them.

[@jcramond73]

I can't believe I'm on the edge of my seat Paul ! Being a former Artilleryman I've always wanted to see the insides of these famous receivers, I've heard so much about them from retired Army officers and engineers.

[@heidgandreiter8438]

Hi Mr. Carlson, there's EVP spirit audio at 0.5x video speed: 23:16 'The energy.. is making me crazy', 23:19 'I hate it', next one possibly says 23:21 'I'm causing.. a mischief'. 23:37 'Have you heard of the Chinese balloon?', 23:43 'Afraid of it'. 24:06 'You're..', 24:08 'lucky', 24:09 'That nobody is..', 24:11 'bothering you'. 24:20 possibly 'I am a spirit in the radio'. Next EVP sounds like Danish language: 24:56 'Jeg hader dig Heid Gandreiter' ('I hate you Heid Gandreiter'), 25:03 'Hold op' ('Stop'), 25:16 'Giv op' ('Give up'). Thank you The Völve, Asatru shaman

[@W1RMD]

My other half ordered me some 1n16 Nixie tubes from the Ukraine as a Christmas present. (Nice to support them). After waiting for them what seemed like forever, they finally got here today. This video comes out today as well. What do I do? Watch Mr. Carlson's lab of course. What I nice looking receiver! I can't wait to get inside it. What a great start to a great year!

[@davidportch8837]

brilliant Paul... really been looking forwards to seeing you restore this receiver... many thanks ... have my seat booked and popcorn at the ready...

[@restoredoutboards]

My CR-88 played beautifully when I bought it in 2022 at Dayton Hamvention. I replaced the filter caps that were physically leaking. But otherwise it is original and I use it almost daily. I did replace the BFO tube after it failed. It was original to the radio…so the warranty was up. 😂 I love this radio. Looking forward to this series. Thanks so much for sharing.

[@MrCarlsonsLab]

Glad your enjoying!

[@albertjones1386]

I came across this site on youtube and your receiver might have been use there. The title is Abandoned Chopmist Hill WWII Listening Station | Rhode Island by Jason Allard.. Here is more information "In this tiny little state (Rhode Island) we had a great big military secret: arguably the most powerful radio listening station in United States, capable of picking up German tank communications in North Africa and Japanese movements the Pacific, among many others. Welcome to the Chopmist Hill Listening Station."

[@javiervidaurre6325]

Wow! Plenty of elbow room. You can spread out. I like seeing your variac head on, your coaxial antenna cx's also. I am intrigued by daily videos. More of a real time record with bite size advance, maybe one hour's work a day edited down to 15 minutes or less. This would provide for ingestion, digestion and reflection and allows one to follow along on their own device. Or run parallel resto projects pointing out similarities between the equipment following similar steps. A project several orders of magnitude above your Echophone EC-1 restoration. I will shut-up now🙃

[@trig6712]

Good Many thanks Nice to see a proper receiver

[@organiccold]

Hi Paul, the new lab makes the videos way more engaging. Those RCA are amazing. 73

[@mcg6762]

Very competent videos and content. I just wish the videos had more modern electronics in them. For me, these old receivers are very uninteresting.

[@jorgeargerich1091]

A-ma-zing receiver! With such amount of vacuum tubes !!!! It had been really a pleasure to use it back then, in the 50's and 60's and on... I start listening to shortwave bands by the end of the 60's when I was a child. On one hand, the bands were "boiling" of signals and broadcast radios (there was still the "cold war" time), and on the other hand, there were no electric noises, like today. I used to spend the whole night listening...

[@davidmccarthy6061]

I was hoping you would get a 1946 broadcast!

[@stansmith7400]

Enjoyed the video. I will be watching the others as well. I have my Dad's National 240C receiver and will be attempting to restore it soon. I do know that it has a bad power transformer. Hence the first step will be finding a replacement or repairing the original.

[@oldergoy]

Glad to have you back and have been waiting for this receiver to come up for restoration. It was my dream to have receiver to own in 1959 me a new ham with an 1154 British airborne radio. A few older hams had the AR88 but I could only watch and listen. I ended up with BC348 that came onto the British surplus market. So I will be glued to your channel thanks for this. John Ve7ban Sidney.

[@mindblast3901]

Had one of these in the 90.s uk Great receive up there with yaesu of the time good video 73

[@joes3485]

Most of these older radios have spring contacts that keep the center shaft of the variable capacitor grounded. If they become corroded it stops the operation and tuning of the circuit it is connected to. Plates shorting together are a possibility. Careful observation of the plates while turning the tuning knob using a bright light can often reveal the culprit vanes/plates. Also there are many variable capacitors which had ball bearings at either end of the center shaft. In some cases I have found a missing ball bearing in the bottom of the receiver. Reinserting one of those is no small task. Clean all the variable capacitor pivot points of any dried out lubrication and renew the lubrication. Clean all of the spring contacts that ground the capacitor shaft and clean the surface of the shaft that touches the spring. Then relubricate those spots. Some units may have dust that has settled between the variable capacitor plates and can cause erratic tuning too. Various methods of cleaning these can be used. I have used the silver heat sink compound made for CPU chips to quieten bad spots on the shaft or grounding springs that have proved to be stubborn. Use the silver compound very sparingly. It can easily get spread to points where you don't want it. Nice project! This should be a rewarding one to work on.

[@OleF112]

Fine work, Paul. Nice to see the first real action on your new lab and bench. 73 de Olaf, Germany.

[@MrCarlsonsLab]

Many thanks!

[@Antony_Jenner]

I was mesmerised by these radios as a child and thanks to Paul inspiring me I now have a Hallicrafters S20-R which I imported from the US to Australia. It cost more to ship than to buy though. I am mainly a valve amp builder but have a pretty good understanding of these radios and enjoy listening at night to foreign broadcasts.

[@tomstrum6259]

Absolutely excellent info content & Presentation style ! ....Your auditory provides the much needed "Forgotten " specialized circuitry & design info....Thx for these grea Detailed videos....

[@MrCarlsonsLab]

My pleasure!

[@bjorngve]

I am from Sweden, we had listening stations also here during WW2. Often located under roof tops in the big cities. Any one happens to know about what the Swedes used? Maybe Ericsson made? I have not researched this. Comparable performance? Now I get an idea about how they used this equipment. There was surveillance at any level. Mail was opened. There was also many telephonists working secretly tapping the telephone wires.

[@paullucas4791]

I had the AR88D, it was so sensitive but very very heavy!

[@DavidTipton101]

Very well built unit Paul. It's amazing what can be made when price is not a factor. Cheers 🙂

[@thegrassisntgreenertodaytony]

It is so clean! I cringed when I saw those oil filled caps (aerovox) I have a Collins 51j-4 I got from auction that is... Gonna need.. first a full analysis, then a lot of work. There's an odd tube substituion made as well as a mod inside, that appears to have been either from Collins or a fairly competant tech. Looking forward to what you do with those oil-filled caps. My plan is to just replace them. Some restorers I have seen will gut them, put modern caps inside. But the oil is fairly carinogenic I think? Can't wait to see this get done! :)

[@littlebear5219]

This is the radio that got me interested in ham radio and electronics . I had the AR88LF some these radios have been used to intercept German enigma code’s at Bletchley park In the uk in ww2 As you say this radio is great

[@markvolstad9380]

I believe the radios were actually used at several monitoring stations along the coast. The encrypted messages were then forwarded to Bletchley Park for decoding. Bletchley Park was a top secret installation, and having large antenna arrays on premises would have been a dead giveaway of its purpose.

[@charlieoscar09]

Really looking forward to this restoration thankyou

[@renowden2010]

Hi Paul - I am another AR-88 owner waiting patiently for some tips on how to get it working again. I heard you say in the previous video that the broadcast band was removed to stop the operators listening to local stuff on duty - I think there was a more operational reason than this. The LF model (like mine which is an early model with a plain yellow tuning dial) has extra low bands 73-205kHz and 195-550kHz which were to pick up the marine bands, so presumably for navy and admiralty use. To do this they had to move the IF to 735kHz which would have been in the middle of the broadcast band. In addition to accommodate the new bands something had to go so 535-1600kHz was lost and the higher bands were squeezed up a bit.

[@johnrobinson8691]

The new area looks really nice, many cool things will be done in there!

[@LarryDeSilva64]

Great overview of the CR88 Paul. Great to see a restoration video in the lab again. Thanks for sharing.

[@benrose7534]

Very neat . man a guy can learn alot from you

[@alexmckenna1171]

A friend had an AR88. It was wonderful!

[@towerman75]

Another great start. This one is special because the age is the same age as me. All I have to do, is to get Mr. Carlson to restore this old body, and maybe I can help him with some of those old equipment restorations. HiHi

[@larrydee8859]

Thank you so much for your very informative video mr. Carlson. You explain things so well. Thanks again.

[@MrCarlsonsLab]

You are very welcome

[@davidsprocket5141]

WOW it's alive! So good to see this restoration. I got an AR-88LF about 1973. I still have it and it works great. No broadcast band coverage. 75 to 550 Kc then 1.5 to 30Mc

[@banditman142536]

When I watch your channel Sir, I hear lines of a song in my head. It goes like this "Simply the best. Better than all the rest." You are the alpha and omega of electronics on the net. I think you are fantastic to watch and listen to. May you live long and prosper, Keep it coming. I would not want to pay your electric bill though.

[@charliebrown5611]

I had one of those circa 1968.

[@alicemoon9008]

No Complaint’s - Great 👍🏼 Job ….. Hi 👋 from Chertanovo Chopper’s Custom Club ….. Moscow City 🌆 ….. Russia 🇷🇺 …..

[@mattbates6887]

The last time I had the pleasure of tuning the amazing RCA AR88D here in the UK, was way back in the late 70s, when I visited an old ham radio op. I was an SWL at the time, so as you can imagine it was quite an experience for me. I was impressed by his AR88D VFO stability on the higher HF bands as I remember, and listening to the 160M Ham band UK fishphone radio was great fun on that receiver. The intermittent tuning problem, might be the tuning variable capacitor earthing springs not making proper contact with the capacitance vanes shaft. Great video, look forward to the next one.

[@wheelieblind]

When I work with computer related technology I sometimes put cardboard down form an old box I don't need anymore. Newspaper has worked for some smaller stuff too.

[@nixraff7802]

it's great that many other receivers will follow in their great videos. I'm looking forward. but first I am excited for part 2 of this restoration of the CR-88

[@johnhodgson5313]

Well done Mr. Carlson. I have worked on many old receivers and studied theory from books from the 40's until recently, then I discovered KZbin. I wasn't aware of using 2 RF stages to keep the local oscillator from radiating out the antenna. The tips and tricks on how to prevent bench destruction from old iron are about 5o years too late for me, but I will pass them along to the next generation.

[@btfou]

I love being crammed with information.

[@eottoe2001]

Did any of the tube "appliances" ever have cooling fans? As a kid I don't recall any did. When had a tube amp, I remembered it put out a lot heat. (I like these videos a lot.I have a lot more respect the engineer and tech people in the past.)

[@MrCarlsonsLab]

Fans cause oscillator drift, so receivers can not have fans. Fans in amplifiers are fine (no oscillators in them,) but anywhere frequency stability is paramount, there can be no forced air.

[@praha007]

I am getting more and more jealous of all those beautifull devices you find. Overhere it looks like all is throwed away or people ask hundreds of euros for old devices..... 😮‍💨