If i want math (and the principal of operation that governs how these things are designed in the first place), I'm sure Carlson has something for me. If I want MASH-style practical field surgery and a visual autopsy, shango's always got us covered.
I used to watch movies as a kid, went to the theatre when ever I could scrape up enough coin for a ticket. Days would see me out in the ditches near town picking up bottles to take to the store for the 3 cent refund on the bottles, to save up for a ticket. One of my favorite themes were about soldiers, and the ones where they had to defuse the bomb in the streets of London WWII flicks kept me on the edge of my seat. Watching this video brings the same sense of excitement to watch that radio go from basket case to flame burning DX system! Thanks a million, love your videos, I always learn something.
What are you going to but in today's world that will last as long at this ole guy has lasted and yet can still be serviced. Funny how you can still get schematics for something 50 years old but nothing for something that is 5 years old ?? Atttttta Boy Shango ! Great Video. Thank You for doing these !
This is a huge job really, so many of those IF cans.... very few people willing to take the trouble to replace all those, you are an electronics saint!
You are spot on about not trying to do the math to get the capacitance values. Even at much lower frequencies, the math only gets you an approximate value. Any engineering course teaches that. Think that's limited to analog? Thinkagain. I worked with an IC engineer in the 1980s, and same thing applies, with the tools available then, but still true even with modern circuit simulation. There are so many factors, including what we used to call lead dress, especially in a 3 dimensional hand wired tube circuit, but again, still applies to printed circuits.
I am Old. Like when this thang was new. All anybody cared about then was AM. FM was just a curiosity. Yeah, I am THAT Old. So no surprise then that the designers focused on AM. Even through the internet and PC speakers this sounds great! Though I never figured Shango was into House Music. Video was overwhemingly informative. Thanks. BTW, JFK got into office with the help of the Mafia and Chicago Machine
I repaired a number of 455 khz IF cans, by carefully drilling off the lip of the brass rivet removing the mica sheet measuring the pf's and then put scotch magic tape over both sides of the mica. Made a hole in the tape where the rivet goes, reinstall everything and super glued the rivet to hold it together. Connected ether 100, 120, 150 or 180 pf micas that were the closest to the original underside. Realigned slugs with the recommended plastic alignment tool that fits the slot in the tuning slug. No problem, less hassle & actually saves time.
I love the chrome squished trapezoid style bezel in front with how it says "Hi Fi" in beautiful turquoise in your grandmother's handwriting as Charles Phoenix would say. Sounds beautiful too! This was a very informative video! I love your no BS style of repair. I thought that the caps would have to go inside the if cans, but it's nice to see they don't have to. Thanks "Garfield" for saving this old beast to live another day.turquiose
Years ago, I repaired an RCA am set that had those riveted cans. I found what the values were from another person in a tube radio forum but, those things came apart exactly like these. I re-assembled them just by turning my iron down and just melting the plastic enough to hold the connectors kinda snug while I soldered the new caps in place then just used a few little blobs of silicon to keep everything where it needed to be. Still plays just fine and that has been atleast 15 years ago. Really enjoy your videos btw!
Fascinating video! Shango worked really hard to bring this receiver back to life. Hearing CONELRAD test broadcasts at those little triangles with "news and official information" on the AM side of the dial would be period-correct, too. I remember seeing radios like this as a youngster.
I'm watching this on Saturday near LA at just after 8pm and you got me tune into Metropolis on my right ear on my phone while I'm watching this episode on my computer and in my left ear. Thanks for posting this Shango. Not a minute too long.
This video is a keeper on such a rare opportunity to see how difficult repairing IF transformers with SMD are and how to do a two step process to get the right capacitor values needed to get the LC filtering right. Very scientifically done by Shango. No math needed procedure.
Great work, it sounds really good. The percent tolerance is the initial from factory, not the temperature coefficient or drift. So you could hand pick a 10% closer than a random 5% and it would be stable the same, assuming its tempco and drift are the same. It should be pertty close with the same style of silver mica. Peak aligning the FM IF will usually cause distortion on stations that modulate close to the maximum since the IF bandwidth is too narrow. To get it perfect you really need to sweep align it.
@shango066 FRIGGIN AWESOME video!!!!!! These are the kind of vids I like, lots of get down and dirty to see how to make it work. Thorough explanation of your thought process as you go, thanks for this EXCELLENT video, I know it takes a lot of time to do these and we all appreciate them. 🙂
I mostly enjoyed this because of the airwaives. I envy deeply all the action on am in the US and that radio sounded really pretty. There´s no am left in Germany, next to none in the UK and they want to scrap fm, too. Then what? I was born in the 70´s near the inner German border and when I was Young I´d never imagined all the goodness to go away. Last in the 90´s I was drunk at home and found a blues show on am from Poland. Memorieees, sweet memorieees...
Used to have a fisher stereo tube receiver with separate AM/FM stereo tuner dials. You could play AM talk radio and mix the stereo FM audio over it. Had 45+ tubes in it. Brown, beige with gold trim. With I still had it.
That TiniSA-Ultra is a really handy tool. I saw it on your channel a few weeks back and I thought I have to order that. It turned up last week and I really like it. Going to be super handy, especially for AM alignment, and way simpler to use than what I've got now. I also like the fact that you can narrow or widen the 10.7 FM bandwidth to whatever you like.
The styrene-skeleton IF transformer tuned by cup cores with this construction was called the "K-Tran". Claim to fame was magnetic shielding. You could place them as closely as you like with no risk of magnetic coupling between them. Most that we see have thin metal plates separated by plain mica sheets. The tension spring under the rivet loses tension as the plastic shrinks with age, and the internal capacitance drops too low to resonate. CB radio receivers from the 1960s were full of them. The estimated repair price for those can be truly shocking when you add up a half-dozen K-Trans in the labor total.
Awesome video. I’ve had various AM/FM tube radios, many of which suffered from very weak reception and I think they probably suffered the same thing. Even after a complete re-tube, they did not get any improvement. I wish I still lived in California. I would have paid you to fix a couple of my units. Awesome job, thanks for sharing with us 😊
nice to enjoy my Saturday Morning with Shango. Just love this exciting channel. Greatful for a nice channel to watch and learn. You do amazing things with really Mint Museum quality TV and Radios. Thanks for the education and fun to deepen my electronics hoby.
I just wanted to offer some in put on radio reception that my improve if you ground on end of am out and fm out to utility ground you may have to go back and forth to see witch on draws best signal hell I use to use roof antenna or the old rabbit ears with dial that clicks as you turn it even that work good near window faceing north or south great Job the radio keep up the good work
I know it is out of the question now days, but back in the 1950's. when it was hot as hell at night, we used to go out in the front yard of our farm house, it wasn't much of a yard, there was no lawn, just bare ground, the front step was a rail road tie, about 25 yards from the door was mom's cloths line where she left the close pins on the wire. No electricty meant no light but dad would bring out a barn lantern and the mosquito's would gather to feast on our blood as we tried to cool off in the night air. Dad used to get an old tire from the pile behind the garage and pour some gas inside it, the light it on fire. that black smoke kept the mosquito's at bay and the light gave a warm glow over the entire scene. There no neighbors within miles to call in the fire we were quite alone. Sometimes dad would pull out his old 22/32 kit revolver and plink at mom's cloths pins, he was a crack shot but mom would get pissed because it broke her pins. Ah for the good old days.
SMD = Red Meat for the Shango-Faithful! Would have been neat to have see the S-curve coming out of the discriminator on a scope. Anyway, great video, and I have to agree that you tenaciously hung in there trying different capacitors. On the silver-micas, many times you can find an old-ham's junkbox that has hundreds as they were recognized as very valuable in the day because it was about the only way to tame a homemade VFO in a tube-set. They are very reliable and the only ones I've seen go bad are the ones with a lot of high-voltage on them.
Superb , I really enjoyed watching that . I have learned such a lot from you . Here in the UK I have never experienced SMD . Maybe climate or the type of if transformers .
dont seem to get 'silver mica disease' , certainly not in the same way, in UK IFTs, they dont 'integrate' the capacitors within the base/former, but use separate caps, so no 'arcing' between them, failure of those separate ones does occasionally occur, usually going low capacity or open, but very rare
its interesting to see ow you took a capacitance reading, i would have thought you would use the electrodes of the caps too. never realised thhey incorporated caps into the if cans lie that. i am guessing they did not give a specific value of the caps in the can and hence you used trim caps.
Wow, I can't believe I know something about electronics shango66 doesn't.. standard practice is you put 120 puff on each side. It's not that critical. Put the capacitor on top in between the two metal tabs after you bend them up, put the capacitor leads through the holes alongside the metal legs out through the bottom. Wrap it around the legs and solder, it holds everything in place, no need for silicone or anything else.
It's super critical, 120 would be way outside the cores ability to adjust. But hey I guess if you only watch the first 10 minutes that's what you would assume
You can calculate the capacitance of the mica wafer by using a capacitor area calculator. you'll need to find the area of the "plates" and the thickness of the wafer. Then the relative permeability of the mica. The formula is this: Farads = permiability * electricalConstant * (areaInMeters / thicknessInMeters) The electricalConstant is "0.00000000000885418781762". And the permiability for mica is 2 to 7... There's probably a common type that's used across all IF transformer capacitors so if you calculate it for one with a known value, you can calculate for any other IF transformer cap.
Oh hello amigo shango, ah boa tarde, bom shango adoro os seus vídeos, vi que você arrumou o rádio, e eu vendo o seu vídeo hoje eu vi a 🐱 oncinha deitada dentro de um saco, você filmou ela, e ela nem acordou... awww ela é muito bonitinha 🐱 Oh hello friend Shango, oh good afternoon, good Shango I love your videos, I saw that you fixed the radio, and I was watching your video today and I saw 🐱 o n c i n h a lying inside a bag, you filmed her, and she didn't even wake up... awww she's so cute 🐱
Legos or Lucite? 13:55 re: "Steps"; silly, earlier i zoomed in to see if Transformer 'tower' pieces slipped together, only to find you included 'steps'. ... _but of course_ Interesting design. the Art of _dis & reassembling._ Nice Work!
I had a pair of those crescent flush cutters, loved them a lot... until the cutter blade sheard off and nearly hite in the eye! Still plan to get a new pair sometime as the cheap flush cutters just don't seem the same
I was able to use medium thick super glue, to fix the removed rivet problem. The FM detector can was SMD twinckulated too. The caps in the AM usually about 100pF .. FMs seem to be either about 33 or 50 puff.
Since the FM IF's are so hard to adjust, I'd have super glued the coil forms to the plastic inside the can. Maybe even leave the trimmers in place and not even try to tune and destroy the coils.
I have a number of late 40's and into the 50's FM radios that have a dual peak when tuning. I assume they need detector alignment. I guess they need to be zeroed.
IHey Shango, is the Tiny SA Ultra suitable to align FM and FM stereo as well as Standard Broadcast, SW, LW etc.? If not what do you recommend for aligning tuners and receivers, vacuum bulb and soiled state? This is a great video on SMD. I'm very happy you posted it to clear up many things that were previous questions I had.
Shango, What about the HP 8640b and the 8656b? I see you using them on your videos? Are they good units to have, which do you recommend along with An ST1000A? Thanks Shango! @@shango066
I think the AM caps needed to be tuned away from what you measured may have to do with the added inductance of the trimmer cap leads. The FM will be even more critical of this added inductance to each transformer.
Oh hello amigo shango, ah! boa noite, ah gostei de ver o funcionamento do Radio, & gostei também de ver a 🐱 oncinha dentro de um saco, ela estava dormindo né.... Bom amigo shango, eu adoro os seus vídeos, boa noite velho amigo Oh hello friend shango, ah! good night, oh, I liked watching the Radio work, & I also liked seeing the 🐱 leopard inside a bag, she was sleeping, right? Good friend shango, I love her videos, good night old friend
Ah shango esqueci de lhe perguntar, esse móvel é o radio & a TV né, a TV você vai arrumar ela ? Oh shango, I forgot to ask you, this piece of furniture is the radio & TV, right? You're going to fix the TV, right?
