Delco High Performance Radio Receiver! [Repair] 

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A complete restoration would be great to watch and then listen to it.

30:23 - I had a problem with 455Khz IF years ago. I was living in Bangor, Me. One of their AM stations, WABI, broadcasted at 910 KHz, *exactly double the IF* ! So, when tuning in, you'd get a beat-frequency that would go to 'DC' if tuned in correctly :) To fix the problem, I just jacked up the IF of the receiver and tweaked the oscillator to compensate.

Great job. These are not just old radios, they are functional works of vintage art.

FYI I worked for Delco Electronics in Kokomo, Indiana my entire career (1977 - 2008), and we made some of the best radio receivers, along with several firsts in the auto industry (first in-dash radio receiver, first push button receiver, first electronic ignition module). I would have been surprised if you weren't impressed by this radio. It's also possible that all cases were made in ivory and painted brown at the factory.

TY. I was having a bad day so I thought I'd listen to you and 45 minutes later the world seems like an okay place again. 🙂

Excellent job Paul! Your genius antenna booster device works like a treat. Not having to physically connect equipment to the radio makes it the absolute ideal way to align a radio. No influence on the test radio, & perfect safety for the test gear! The huge difference after alignment demonstrates the sensitivity of the radio, & the perfection of your test gear! A restoration video of this receiver would be an excellent watch, where I'm sure you could make it perform even better, if that's even possible. Thank you!

Can you align, and peak up a radio, without test equipment or very limited cost test equipment. And if so do a video on how you would carry that out. Obviously not expecting the results to be as perfect but still put the radio in to a good state of usability. Keep up the good work on the channel, just recapped my first Ekco U319 radio, inspired by you channel. And it works!! Or at least receives channels on all bands!! Thanks from the Norfolk Broads UK

WOW!..indeed. Can only imagine how full restoration of this receiver will improve the performance. This is going to be a solid project. Thanks for the video and work.

29:20...Your "Power Antenna" lightly Inductive Coupled alignment creation is Deff the best "Non-Loading" non-Disruptive Rf/If alignment method ever seen !! ...Big thx for showing this Superior technique...

Thanks a million Paul, for working on this great radio. I love old tube type radios. I will be anxiously waiting for the restoration on it. All the best from Gene in Tennessee. 😄

I don't know half of what you're saying, but I love it. Haha!

I've not worked on any of my radio collection in 10 years but after watching some of your videos I'm ready to resume. Thank you for reminding me of how much I enjoy bringing them back to life.

I really like when you work on these types of radios!

US buildings that used 110VDC, I found the Electra Hotel in downtown Chicago. It had a steam plant for heating, domestic hot water and to Generate its own electricity. In the room that I rented had a sign above the one outlet stating caution 110 direct-current. Got a tour of the boiler room it was quite impressive. (Talk about off grid)

Wow Paul great video! Keep them coming! I learn so much from you.

Hmm, I have learned from You, that these Old, almost Ancient Radios, receive very well and this was long before Transistors and Integrated Circuits were invented

Your stress relief on the power cord is a great idea!

Finally a normal mr.Carlson video Also Richard from the channel Learn electronics repair tried to contact you about a rare tube filled thing if you were interested in it but your Email did not work or could not find it ... anyway you may want to contact him .. if he still has it .. tell him dutch told you about it it was a german device

As an engineer myself it's so great to see this old radio working again. It also reminds us just how good some of these older tube sets were :-)

Keep your grounds close, and your neutrals closer.

Would've been scary if it said "this the civil defense network, please proceed to your nearest shelter and await instruction from a civil defense official, repeat, proceed calmly to your nearest shelter and await further instruction." 🤯😳😱🥺

Zap straps! Is that because they are attached to something electrical? 😜 And then you said zip ties! I can count on no fingers that I have heard of zap straps before I saw this video! Cable tie & zip-tie for the people of down under! 😁 Learn something new every day, besides the electronics that I love to watch! 👍

Is “Zap Strap” some Canadian brand of zip ties? Never heard that in my 55 years.

I've gotten somewhat skeptical about published IF frequencies. Did a radio for a friend and noted that the cans were tuned to about 445kHz (not a typo.) I retuned them to the published 470 and found the dial wouldn't track worth a hoot, so I reset it back to 445 and everything was back to the way it should be.

I think I'm going to start shopping for one of these All American 6 radios. They sound great. Although there aren't nearly the number of AM broadcast stations around as there were, There's still enough to make getting one worth while. Thanks Mr. C for another great video.

I was watching Adam Salvage and he was talking about how things are not made to be repaired just replaced. He was sharing about the disconnect young people have with learning how things work and how to repair things. He used cars as an example and how new cars are designed to not be fixed by the owner. So as with him, thank you for showing and passing a long your knowledge so just maybe these skills are not lost to time.

Interesting that there is no tuned circuit between the RF amplifier and converter. Also interesting that they used 456 kHz IF to avoid RCA patents.

sir,question please. theres only 3 videos on rx bc348 restoration. may i ask where are the rest. you started resto n then they vanished.. i only just came in so the resto was in '23.. where can i find full set please. ty Sir

Interesting that it tunes all the way to 1700 kc as old as the radio is.

I want to understand "hot receiver" in context with radios I actually own -- is it hot compared to say an ic-705 or is it hot compared to say an 80s pocket transistor radio ?

I think your devices for showing the leakage in these old capacitors are clever and educational for the purpose of these videos. But , the conclusion I've come to in the end of the day is that all these old caps are simply to be assumed as bad and are to be replaced. It's just a matter of their age, as they're all long past their EOL. No point in even testing them. I've given up even checking them, because I seldom find a single one that is any good. This includes the electrolytic caps in transistor radios going back as recently as the early 1980s. On a conventional cap tester, I'm finding many of these are now showing readings 30-50% higher than spec, indicating substantially increased leakage. One can only wonder the implications for all the car electronics that are full of these things that are sitting in a much less friendly environment. The modules become unobtanium after 10 yrs or less, and the car becomes totally unfixable.

Very interesting part about those caps / elco's. Like you, I have the experience that most "cans" are "gone" after more or less 50 years. Even less, depending of the heat (from nearby tubes) they had to endure during their life. Thanks for uploading!

Blessed love my brother, Is it possible for you to repair a ham radio for me please an thanks, I watch your videos, and think you are the right guy for the task, I have learn a lot from you bro, You are great bro, watching from Jamaica west Indies !!.

It's a nice and simple radio with some quirks - I'm pretty baffled by the chassis and signal ground connections. Aerovox looking fine and dandy enough for restuffing and while I'd certainly want to put the HV lytics inside the cardboard tube, its small diameter makse it impractical or impossible to do so. I don't tune IF filters by ear - I always do it by measuring the DC voltage on a demodulator diode after disconnecting the automatic gain control feedback line to the stages. Going back from last to first filter and reducing the signal level after I get to the sweet spot. I agree that tuning the IF filters often works wonders - it's a pretty easy adjustment provided you have a sine wave generator (even one that goes to 500k...1M) and a frequency counter to ensure precision.

Be good to see some sensitivity and selectivity measurements with numbers 😅😅😅

That's a great gizmo you've invented, Paul. Nice radio too. Looking forward to the restoration.

These old tube sets work a lot better than many people today would think. I've lined up many radios like this, and yes you can do it by ear. To get the signal into the set without connecting the signal generator directly to it, I just take a lead from the sig. gen., and make a loop of a few turns and simply place it near the set. I keep the signal low, so the a.g.c. in the set doesn't kick in, and line up the IF like that. So a signal generator and a good ear is all you really need!

High Performance Radio Receiver!

Take some good pictures of how that dial is strung if there is no diagram! 📻

I've been missing these kinds of videos so thanks for making one. It's a trip down memory lane for me for when I first got into your channel about 4 years ago. I've really come a long way (and I've got a long way to go) with my electronic knowledge in that time. Thanks for being such a great teacher!

So when you end up with hum after replacing the multi-section capacitors, what sort of things should we look for to make it go away? I run into this when I'm doing my amateur restorations of radios like this or things like tube CB radios. I love the antenna 'caster' device! So handy and useful when you're working down in the basement like many of us are.

Great Mr Carlson sir nice I enjoyed the show thanks for this video sir you are awesome ❤️ ❤😊❤

I look forward to the restoration and multitude of tech tips you provide. Hopefully when testing at night you can receive KNX1070 from Los Angeles.

They switched the chassis side because the service receptacles and plugs were not polarized. Therefore, if the chassis side was connected to the hot side of the line it would be at full line voltage 24/7.

Great video Mr C. Wish we made things like this agn. LFOD !

Sometimes the AA6 works dramatically better than the AA5. You wouldn't think that just one more tube would make such a huge difference.

The harder to find Delco model R-1236 with pushbuttons circa 1946. It actually came only in the ivory finish. The non push button version came in either ivory ( R-1234) or brown ( R-1235). Interesting "junk box" power booster antenna none like I have ever seen! Impressed by your cleverness using a Compactron Mr. Carlson. Of course I don' t want to possibly send a signal out to the whole neighborhood. Or do I? LOL. Excellent revival and alignment of an old tube receiver!

Great stuff love the vidoes. After starting to watch your videos some years ago I have since renovated many valve radio sets, sadly in the UK there is almost no MW or LW. Of an everning and using one of my ham antennas I can often pickup up chinese stations, for some reason. I shall be joining Patreon at some point soon. I really want to build a super probe, your capacitor tester and now you have that aerial thingy too.

Two weeks have passed,since i have finished my last tube radio project, a nordmende Carmen 57,last Job was restuffing the power supply filter capacitor, 3x 50uF, restuffed with 3x 47uF 400 volt ones,and polishing all brass parts at the Front of the radio. Works perfect, no hum at all,amazing Sound quality. Even the original schematic is still intact, which is really helpful, for checking resistors, and all the voltages.

My grin was directly coupled to the alignment stick as you tweaked up the signal. Reminds me of younger days out in my grandpa’s fixit shop.😁 📻

Paul, please include some information on what string would make a good string for the dial string replacement.

Is the difference from a 5 tube to a 6 due to a pre-amp or RF amp in the antenna side?

Those old tube radios predating the NRSC mask by several years have such good audio even with the dumbing down of the transmitter audio chain. I believe that a radio like this coupled with a well matched antenna at the transmitter site can come really close to fm ! Great audio bandwidth! Sometimes newer isn’t always better

Looks like the power cord still rubbing against the tuning shaft😅 testing old capacitors is a waste of time

thankyou sir for sharing your knowledge, experience and the best home lab, a dream home lab i wish i had. Your a gentlemen and i love watching your content,

An awesome video and a real piece of electronic artwork. I absolutely love watching your videos and learning new tips and things I didn't know previously! A huge thank you!

Mr C, you need to try the radio at night with an external antenna to see how many stations you can get.

Enjoyed this video, Paul and always look forward to keeping up with your latest installment. Love your new shop and your lift truck!! I wish the testing gear that you put out on your own was in kit form as I would purchase all of them just for the experience of putting something together that you designed but I do know there are just so many hours in a day and I do appreciate that you even make these inventions available to us. Thank You!!

really enjoyed this... as I do all of your videos... Many thanks Paul... Great little radio...look forwards to the full restoration in due course.

They used that cabinet in many RCA sets, also. I have several.

Great job Paul you make it look so easy.

What do you do with all the equipment you repair? You could probably fill a large Barn with everything you have demonstrated on RU-vid. Where do you buy your potential projects. eBay? Amateur Radio Flea Markets? Antique stores? I really enjoy watching your troubleshooting.

Hi Paul .. I've been following you about 3 years, full of enjoyment. In fact you unwittingly motivated me to join the Ottawa Vintage Radio Club and talk up some of your creations. Awhile ago I loved your re & re of a Knight local AM transmitter ('intercom or baby monitor), and now I see your power amp is rather like a low-power a.m. transmitter. We're interested in the low-plate voltage 'space-charge' mode tube receivers, and now I'm wondering if low-voltage transmitter would work. Would be so much fun to see you explore space-charge tube radios: good projects for youngsters are in reach there. There were very early 'hikers' sets with one or two s.c. triodes.

How are you? I hope you are very well. You are an inspiration to me, I watch every video of your channel. I think you are an inspiration name right so I think your videos should be released regularly which inspires me a lot. stay well Weren't you uploading videos to Facebook?❤❤❤❤

Always interesting!

Thank you for doing the radio alignment on this Delco. I’ve had some difficulties learning how to do it. You made it simple to understand. If I may I’d like to ask a question not related to this video. I have an 1950 Buick with a 6 volt battery. I’m unable to jump start the car because the newer cars are 12 volt. Can you provide some information on how to drop the voltage to 6 volt if I use a 12 volt battery? Many thanks

I have been dealing with electrics/electronics for nearly fifty years and have NEVER EVER come across a mains switch going short. We have fuses in our plugs here in the UK in any case. If there is a fuse of the correct rating, in the live(hot) it will blow whichever order it’s connected in. I think someone assuming the set is “ safe” when switched off, or the socket not being accessible to switch off to change the fuse presents much more of a risk.

Well that electrolytic cap, either was bad or good, was completely normal to test as "leaky" after 40+ years of disuse. It is of course good to replace it anyways, but it would be even better to try to reform it via a HV current limited power supply, and then test it for leakage and capacitance :)

Hello Paul. Can you let me know if I can purchase a kit of parts from you to build your Capacitor Leakage Tester. 73 Gerald

I'd like to know how to intercept a 3G cell signaĺ and convert it to 5G. Obsolete equipment that still functions can no longer communicate as 3G service is decommisioned.

Also seen this report twice. Thanks for making it. 73 pe1krx

I rewired the power switch on one of my radios to break the neutral going to the tube filament on the 12sq7 and used a polarized plug

Question, why it’s not possible to align using a station that you receive ? Why do you need to inject 465khz ?

our UK plugs all have a fuse . Awesome repair

When you change the switch topology (switching the live side) could you also add an earth ground to the chassis using a 3 pin power cord? And if so, would there be any advantage to doing that?

Another superb presentation. Looking forward to the restoration.

Why would you not use a Heyco strain relief? Why couldn't you keep the switch connected as is and just connect the polarized line cord appropriately?

Was 'high performance' back then equate to 'high-end' today?

Comment for the algorithm.

Thanks Paul 🙂

that 2 section filter cap is NOT the original.

I really liked the explanation of how a leaky Cap can read high, can't say I thought of that. 🙂

High performance technician makes all the difference !!!!

Radio Google, radio Gaga! 🎩📻

Zip-tie works for me.

Easiest. Radio. To. Rebuild. Love. Them. Very. Reliable

Desire to learn something, tho still lacking process, makes it difficult questioning if Logic was used or established 'Rule' was 'broken'. _you know, for "safety"_ re: 14:05 'making up own symbols'. Isn't that how 'standards' were created? lol "Funny" may be what's noted today. 17:22 *Thanks,* I'll take in All variations in moderation, _still learning._

how does all the ele works with no moving parts to run so many years with no failed run ?

Tanks Paul! Looking forward to this restoration!

Do you sell any of the radios that you have repaired?

Great video! I am excited to see the restoration.

I am wondering about that tuned circuit coil with the capacitor that should not be changed or else you will have to tune it frequently. Why not use an NP0 Capacitor?

Hooray!! Old radio restoration coming!!!!

16:26 Maybe it can pick up the modern rock station at my workplace haha. I kinda wanna send my AA5 AM/FM set in for a restoration. Maybe I'll poke ya on patreon about it further?

Great video, Paul. Do you restore viewer's sets? I have a 1948, Zenith model 7H820 AM/FM radio. It still has the original prewar, Armstrong, 42-50 MHz FM broadcast band and the other two frequencies It would make a very interesting video. I live in Manhattan and could ship to your address in Canada. Please let me know if you're interested.

35:40...The post-Realignment lab/basement sensitivity performance is Incredible !! ...Even without the Outside antenna connection, If you had turned Off all your other lab Equipment & other nearby Interference generating Sources, I bet it Would've picked up many Distant stations better than most "Today's" newest radios !!

You can use an ESR meter on caps the “seem” to have gone up in value.

Very helpful restoration & Alignment tips...Very interesting how Delco Economically incorporated the Rf Preamp stage while using just a standard "2 Gang" AA5 non Rf preamp type variable capacitor Without losing any hot, sensitive, long Distance reception performance !! ...I would've Assumed a much Lower sensitivity performance with the compromised Un-tuned preamp Plate coupling design but it seems to deff work Very well !!

I know of several people that do retro-computer repair. They test ESR but, they won't ever test for leakage because the ESR is good. So you don't see them do a lot of recapping. I'm talking Tantalum caps from the 70's and 80's. would those 50yr old caps be notorious for leakage. I know Tantalums can go bad. They are basically used as filter caps for the IC's in the circuits. myself I just don't take the chance and do a recap in any case. Capacitors are so much better today then they were when I was growing up. Electrolytics are almost always still good. I won't replace those unless I see them leaking or bulging.