1946 Secret Listening Post Radio Receiver - Will it Work? Lets Restore it - The RCA CR-88 

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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…🙂

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.

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 😊

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.

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.

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.

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

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.

Great to see the master at work once again.

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."

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.

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.

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.

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.

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.

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 RU-vid 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

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

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

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.

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.

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

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

❤️❤️ 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.

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

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

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.

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

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.

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

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.

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.

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 .

Very interesting introduction. Thanks for the refresher course.

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

Yay, back on the bench !!!

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..... 😮‍💨

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

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 ;-)

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

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.

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

I owned one of these marvelous receivers in the mid 70s -- the golden age of international shortwave broadcasting. I've owned many fine radios since then, including my current Elecraft K4, but none gave me the sheer listening pleasure of my AR88LF. In 1977, I added digital frequency readout by building the kit highlighted in the February issue of Popular Electronics. For an immersive taste of how this receiver was used during the war, I highly recommend the novel "Enigma" by Robert Harris.

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

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

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

Mr. Carlson your knowledge is amazing!

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

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

I do some work on heavy, old test equipment, so I made a big Lazy Susan with a brake on the side. I put the gear on its side and just spin it around as needed. At first glance I figured this rig would be comparable to my SX-25. But as you go through the circuitry I see this was a sports car compared to my daily commuter car.

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...

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. !!!

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!

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

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

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.

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

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

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.

Ready for part 2 of the Grand Receiver Restoration Series, being able move the heavy item around is very smart safe.

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.

Great video Paul and thanks for sharing.

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

My dad had a similar sized WW2 era radio. It was one piece of electronics that we curious kids knew better than to mess with. 😀 He donated it to a local warbirds museum.

Hi there, very keen to see you start work on the CR88. I have an AR88 that I use regularly for 160m AM nets. I'll be watching each episode closely for tips on AGC and alignment. Many thanks, VK3AKG.

It’s a beauty!

This is a really cool radio, when it first came on it sounded so good way better than most. Good video Paul.

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.

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.❤

Great to see the master at work once again..

It is not only amazing that you got this receiver working but that it is not bodged in any way. Well taken care for but it does have some issues due to it's old age. Can't wait for part 2 Paul!

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

Good Many thanks Nice to see a proper receiver

I love being crammed with information.

Time to get out the popcorn and enjoy, once more, Mr. Carlson's fantastic work. Looking forward to this one. Thanks, Paul, glad you are back at it!

Hey Paul, may I suggest placing a mirror suspended over your bench at an angle so it reflects from the surface of your bench then bounced to your camera. This way you have the freedom to work at the bench and the viewer have a top down view of your bench. We used this setup for decades for cooking shows to get a view into the pots and tabletop. Just my $0.02USD

Felt floor tiles are also good to slide them boat anchors over a workbench. The felt goes downward and the equipment rests on the underside of the tile

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.

oh, I'm looking forward to part two. I imagine delving into checking some tubes or capacitors to determine which parts need cleaning or replacing? Can't wait to see the process. Love the 30 minute episodes format.

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 RU-vid. 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.

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

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

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

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

I have one of these, used to belong to my dad. It still works perfectly too, weighs a ton, quite literally bomb proof, they had to be! Still have the manual for it too! Although mine has the model No. AR-88, & has a black fascia panel, but looks the same, except yours has an additional control knob at the bottom centre of the faceplate. Your multimeter, with detachable display, never seen one like that before, very handy!

I enjoyed this video and looking forward to the full restoration of this receiver and others. I have an old Hallicrafters SX-25 that I got when started in Ham Radio back when I was just entering jr. high school almost 40 years ago. I thought is look old then as heath kits are what took my interest back then. Now I cherish this old "boat anchor" and hope to have it restored some day. I thoroughly enjoy you channel and it's an inspiration to me. Thank for sharing your knowledge.

That is such a beautiful radio and as old as it is, it is still in good shape. Definitely need some TLC. I was really amazed on how clean the chassis was. Thanks for sharing the video hello from the Texas hill country. Steve

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.

Really looking forward to this restoration thankyou

It's so good to see you working on a restoration again. This RCA radio will be hard to find a blank frequency on the AM broadcast band when you are done with it. Having 2 RF and 3 IF stages this will be one very sensitive hot radio receiver!

👍 Looking forward to the rest of this series. The snippets of broadcast station audio we heard sounded amazing.

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

A friend had an AR88. It was wonderful!

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

I'm 66 now, but back in the 1970s I was really into short wave recievers and ex military sets were still available. I had the famous " 19 set " and "22 set" , B 209 ect but I always wanted the AR88 but could never afford one! I was always impressed by the quality of construction and the fact that they were designed for ease of maintenance and repair. Nothing can come close to listening to the short wave bands by the warm glow of the dial lights , and the distinctive smell of warm varnish and hot valves ( tubes)! It's ironic that now that I am well able to afford one ,they are very,very scarce in the UK. This one looks absolutely mint condition, and totally un molested.

Good to be back on your channel Paul, and very happy you picked the AR88 as the next project. I have two of these beasts which i need to re-visit, so I will be keen to follow your journey. Interesting colour scheme on yours, not the normal black. My first AR88 i bought many years ago, and it has all the tuning tools, plus the allen key!!

As a teenager in the1960s in the UK, there was still a great deal of government surplus equipment available from WW2. The communications receiver that I wanted was the AR88D, but it was way beyond my means at the time. What was the difference between the AR88D and the CR88? They seem to be very similar externally.

Wow! What an amazing looking receiver. Really looking forward to seeing this get back up to par!

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.

I has an AR-88, quite a lovely set. Ceramic tube sockets and band switch wafers. It was the 90 Lbs that got old, sold it.