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
Paul, no need to ever apologize for camera movement or out of focus moments. The content and educational value of your videos more than makes up for whatever little camera shifts happen while you move between schematic diagrams and the equipment itself. Great videos, sir.
Really enjoyable. It is always nice to know that you're not the only guy who gets done with a rebuild, then gets the opportunity to troubleshoot the rest. Like the Echophone EC1 I did. Gave me lots of interesting challenges.
@MrCarlsonsLab you mentioned that the oil filled capacitors had some nasty chemicals in them, but it's only recently that I discovered how nasty. Would you be able to do a segment on PCB and it's dangers? It's an important safety aspect. Thanks for all your hard work on these videos, much appreciated!
I have a AR88 which I’m also restoring at the same time as this. Mine is a lot rougher than this. Though it seems to have Bletchley park history which I like
Nice! When you go thru the IF alignment with sweep and tracking scope, would appreciate detailed explanation of scope and generator connections and set up. I've never been able to get a sweep generator and scope setup to work. Many thanks!
Paul ... Thanks for letting us sit next to you during this journey Sir! An old tube receiver was my introduction to SWLing in the early 60's .... sparked a love affair with electronics and Ham radio - 73 - KF6IF
Amazing results. My unit could use your talents desperately. No one around here does this type work. That RCA 88 is a very nice radio. Have learned so much from your videos on how things work. Thanks for posting all of them.
Wow! I play with electronics, but I will never work on such a thing. But I still love to watch your videos and it's great to see and hear how you describe what you are doing. You could have said: "I looked at the wiring" and that would be technically enough. But you describe it far more in detail because you know that is the difficult part. Great!
I’ve never seen a tube tester. That thing is cool. I remember as a kid a tv repairman coming to the house with a leather bag like a visiting doctor with a bunch of tubes and fixing our tv.
The reason the power supply filter cap has to be replaced is that it is a 3 section unit consisting of three 4 mfd oil impregnated paper caps, each rated for 500 v. When the set is put into standby, the B+ is removed from the tubes and its voltage soars high to 480 v. The old 3 section unit can no longer reliably withstand that and the dielectric begins to break down. You are correct in using polypropylene film replacements provided their rated v. is at least 630 v. Also, it is a fool's errand to try to retain the stock capacitor can because the 3 capacitors are potted in tar inside the can, making for a difficult messy salvage job.
Hi Paul. It is always a pleasure watching you working on a lot of electronic equipment, but most of all, refurbishing vintage short wave receivers. Since 1974, I have owned a Hammarland SP-600 (great receiver), which around 10yrs ago stopped working. I am looking forward to see you restoring one of those!
I think this is the first project I've seen where so many tubes needed replacing. This radio must have had some serious use. It's going to be a great one once it's fully restored and adjusted
The professional way to upgrade an old CR-88 communications receiver indeed! Your videos are both very informing & entertaining to say the least! Thank you...
Working on an IG-82 (AG-10) Heathkit Sine/Square Gen. There is one 4uf film cap. It connects from the flatness adjust circuit to the plate of a 6CL6 (104v). Based on all the info you've dropped, here and patron, new stuff (parts) are way better build, and don't over think it with replacements. I'll post pics and the community when it's completed. Thank you.
Watching Mr. Carlson install the three electrolytic capacitors reminded me of the three same caps I replaced in the three AR’s I restored. At the time of these restorations I elected to take the route of removing/separating the original power supply electrolytic inner encasement from its outer metal chassis enclosure cover. I mounted the replacement electrolytics on a perfboard in the chassis opening where the originals were mounted and covered the perfboard with the original outer power supply metal cover enclosure, minus the inner capacitor encasement, so it maintained cosmetic originality. I was able to do this without compromising the inner encasement containing the three original power supply electrolytics. Those three electrolytic capacitors are mounted in a sealed metal encasement inside the chassis mounted outer metal enclosure cover (riveted). This original configuration may not be the same for every RCA AR/CR produced but this was the way it was for the three AR’s I restored. You never know what you might run into with an AR/CR restoration. I have the original electrolytic encasements stored in my shop and still no signs of leakage from any of them. I would not recommend the method I utilized unless the inner electrolytic encasement show signs of physical leakage and at that point removal is a must. If removal of the electrolytic encasement is require proper PPE is worn as it hard to say what chemicals and/or oils lurk inside that encasement. Mr. Carlson’s method is a lot easier and faster and, as Mr. Carlson states, a lot more efficient without having to utilize that long wiring harness. I continue watching this restoration series with enthusiasm!
With an old-school analog tube tester, it's always nice to START with a new tube or two in order to establish how that tester will display a healthy tube. MOST tubes on my analog tester go about half way up the good scale.. but 6AQ5 only goes 1/4th of the way up on a fresh one.
Nice to see that you were able to locate a connection diagram for this receiver. Looking at the old Rider perpetual trouble shooter manuals, I've noticed some manufacturers included connection diagrams. Most did not. I'm in the middle of an old Sears Model 1806, variant 2, receiver rebuild. This unit was made by Colonial. The schematic is as bare bones as you can get. It shows all the circuitry, but a lot of stuff isn't labeled. There's nothing to indicate what coils are associated with what band. The tube elements are shown, but there's no pin outs. You have to refer to a receiving tube manual. I've been doing a lot of wire chasing with a multimeter.
Mr Carlson, I have used those same Polypropylene capacitors in some of my restoration work. For example I used them in restoring a 1929 Majestic 92 radio's power supply and in a 1940's HP 300C audio generator. Very nice compact caps.
An impressive unit Paul, lots of room to hang Capacitors which makes it easy. I'll be interested to follow along with your troubleshooting efforts in the next episode 🙂
in my AR 88 the 2.7k dropper resistor to the VR 150 was faulty. There is also a lot of heat traveling down the post wires and the solder joints became dry to the VR150. The BFO components are inside the BFO can and over time they became cooked due to being inside the can from the heat of the valve's.
Hello, Mr. Carlson". It's been a while since 'I've said hello and wanted to do so, especially with this series your doing with the RCA CR-88. The time you're taking to explain in detail, steps and procedures in resurrecting this receiver is well-appreciated. Plus, you make a darn good teacher the way you explain the schematics. As a novice, I appreciate your time and effort in your presentation. Thank you again for educating me and keeping me out of the Bingo halls. Cheers my friend and stay safe.
NICE. Two memories popped in my head... One, my mother asking my dad if he had unplugged the set and him getting knock on his keaster. Mom shaking her head, chuckling and saying, "I warned you". The second was not so much a memory but I would not have been surprised if Fibber McGee and Molly came blaring out as U were tuning the dial. "Be careful with that door.... Fibber!???"
Paul, I dont remember if you ever discussed this, but how does a youngish man like yourself learn all about tube equipment? Where did you get your knowledge and build your expertise? By the time I got into work in the mid-70's everything was already solid state so while I did learn about, for example, current limited variacs in college I never really had to apply any of that knowledge. I remember my grandparents having a tube radio when I was a nipper, the glow used to fascinate me (and scare me) but I never had the opportunity to work on anything with tubes. I live vicariously through your videos :) Thanks again, this series has been really interesting.
👍Thanks for video. I was little surprised that you had to replace all(?) the 6SG7s. Though, I suppose many of these sets clocked up many operational hours which might explain them all being low gain.
Nice video, once more Paul. One thing I wondered about though. You were happy with the new filter caps being closer to the filter coils. Less noise to be picked up (if any). However you decided to leave the old wires in. Why not remove them altogether to eliminate any potential noise being picked up?
The "W must mean weak" made me chuckle! For sure, in your case, W sure did mean weak! If I remember right, W was a code for a ruggedized military tube. Which for a CR-88 would make a lot of sense. :) Great video series! If I ever see one of these AR-88 or CR-88's for a price I can afford I'll grab one. If I remember right, you've got a Hammarlund Super Pro awaiting restoration? I have been working on a military SP-200 (BC-794) for almost a year now (full restoration) and very close to firing it up! :)
You're right about tubes with a W being military grade, but that is if it's a part of the factory printed tube numbers. The W he described was hand written on the top of the tube.
I replaced the rectifier tube on my AR88 with silicon diodes. This was a bad move as the reduced forward resistance of the silicon diodes caused the first smoothing inductance to burn and go short circuit because of the higher current pulses. It also raised the HT voltage by about 20 volts. I managed to cobble up the bias circuit, but I should have left the old double diode in place.
OMG how did you get my dads soldering gun... :) That thing was scary. I've used your technique to replace capacitors When I did my Heathkit Oscilloscope cleanup. It worked great and everything still looked stock and nice
Paul, an idea for a future video would be to discuss technical issues related to those bathtub capacitors. What is the point of putting some caps in an oil(?) bath inside a metal box? Are they off the shelf parts or always custom made? Three caps in one box with two of them having a common end with a third that has its separate leads seems a rather odd design. Why not three separate caps in the box and then connecting the ends of two together?
Your videos are so insightful for restoring old radios. I rarely see an older FM radio. I have a 1948 AM-FM Stromberg-Carlson (any relation?) Model 1204- 7-tube unit that I'm working on now. Any special advice you'd offer on FM radio restoration? 73 - KB4JN
I like your restaurations, but I tend to replace the "chassis" mount capacitors by remade ones. A dealer here in Germany has them, made be FTCAP. Most likely a variant of their "S series", but in the classic values like 8+8, 16+16, 32+32, 50+50 or 50+100 µF. They are quite expensive, but available and it somehow feels better to me instead of sticking modern ones on the underside of the chassis.
Paul, have you done the National NC-300 yet? (I searched your channel but came up empty). I know it might not be universally interesting given it's a ham band only receiver with no BC band to offer the dramatic sounding first-firing-up magic from a chassis that looks like it couldn't even light up filaments (I love those moments too, btw). You've inspired me to consider restoring a 300 and recapture those days as a kid, 65 years ago, when I excitedly operated 40-meter CW!
Paul, if a circuit calls for an electrolytic capacitor, and you can replace it with a non-electrolytic capacitor, then why would the designers bother using the electrolytic to start with? I'm sure you've covered this previously, but if so, I must have missed it.
Try getting your hands in there. It was hard enough to snip the tail off the zap straps with a small clipper. All that factory lacing was done outside the chassis, (on new flexible wire.) The wire is as hard as a rock now and took heating to gently move it.
The three capacitors in the can are electrolytic, but you are replacing them with a poly capacitor. Are you using "Metallized Polypropylene Film Capacitors" in this restoration? Can you use these capacitors to replace old wet-tantalum capacitors in old test equipment?
I restore radios and most of the AA 5 sets I see have a phono jack. This Bendix I have on the bench has a 3 section filter which is isolated from the chassis. I cut the connections to the can ground and left the remainder of the filter wiring in place reasoning that if a section leaks there would be nowhere for the current to flow. I then located the recap in an open section of the chassis and wired to the set as good practice allows. Does this violate that practice?
Enjoying this series and following along with my own receiver. Is there another way to identify tired tubes if you don't own a tube tester? There aren't many around over here
I many cases you can measure the voltages (and by this, indirectly the currents) around the tube and take quite an educated guess. For example, if they have a cathode resistor and you see that plate and all grid voltages are in spec (or higher) and the drop over the cathode resistor is low, you can be pretty sure that the tube is weak.
Great video and work Paul. A question if I may; do you think that 5 lead filter capacitor was custom built for this receiver, or would it have been an off the shelf component at the time? Seems so specific to be off the shelf. Thanks.
@@hestheMaster Why wouldn't they? Rubber was a perfectly good wire covering. How could they possibly have forseen that it would be deteriorated in 80 years? Now we know the cloth wiring held up the best. But back then cloth may have been considered a hazard used in the lowly consumer-grade machines. RCA and Crosley used rubber wire. Others may have also. At the time it may have been considered superior. Context means everything.
@@totallysmooth1203 Hence me saying there were exceptions. Before the war years ( 1938 to 1941) stock of rubber covered wiring was used up and they went to cloth wires since that is what was only available until the war production board came about so only materials approved to make war products. After the war years ( post 1946)they still had plenty of cloth wiring to use. Did they also use rubber wiring? Yes, some manufacturers went back to rubber for a time.
Hi Paul, nice restoration video and series. However there is one thing that irks me about your methods. First, you really do a great job of retrofitting new-technology components into the old architecture. however your use of cable-ties (you call them zap-straps) is incredibly tacky to me. Instead, you should be using period-type waxed-nylon lace which is either available in natural (an off-white) or black. The lace is super-strong, and allows you to dress cables much more neatly, (close-wrapping) or that require any turns or off-branches. Additionally, the lace will never break or become brittle, unlike cable-ties unless you buy the expensive ties (and know the difference!) Those plastic 'zap-straps' just have to go, they are just so ugly and inappropriate--please stop using them.! Thank You! 73...
![1940's Forestry Radio Receiver And Transmitter [Teardown With Circuit Description]](http://i.ytimg.com/vi/H7RKEDPUy-8/mqdefault.jpg)
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
Paul, no need to ever apologize for camera movement or out of focus moments. The content and educational value of your videos more than makes up for whatever little camera shifts happen while you move between schematic diagrams and the equipment itself. Great videos, sir.
So fun to hear in radio someone speaking of a website, but the receiver is from 1946..
Really enjoyable. It is always nice to know that you're not the only guy who gets done with a rebuild, then gets the opportunity to troubleshoot the rest. Like the Echophone EC1 I did. Gave me lots of interesting challenges.
The Echophone is a fun receiver to rebuild, I would do it over again. Thanks for you comment Leonard!
@MrCarlsonsLab you mentioned that the oil filled capacitors had some nasty chemicals in them, but it's only recently that I discovered how nasty. Would you be able to do a segment on PCB and it's dangers? It's an important safety aspect. Thanks for all your hard work on these videos, much appreciated!
Paul, So wonderful seeing you bring this grand old receiver back to life and better than new. As always, I'm in awe of your knowledge and skill.
Thanks for your kind comment Kevin!
Wow, 30+ minutes of expert instruction, 2 cups of coffee, and a smile on my face … life is good …
I have a AR88 which I’m also restoring at the same time as this. Mine is a lot rougher than this. Though it seems to have Bletchley park history which I like
Mine is in the garage in a
right mess 👎🇬🇧 used to work it along side a KW Vicroy. Thats a mess too. Covered in Cob webs.
Friday evening with Mr Carlson :-)
Nice! When you go thru the IF alignment with sweep and tracking scope, would appreciate detailed explanation of scope and generator connections and set up. I've never been able to get a sweep generator and scope setup to work. Many thanks!
You just can’t beat old school tech for reliability
Paul ... Thanks for letting us sit next to you during this journey Sir! An old tube receiver was my introduction to SWLing in the early 60's .... sparked a love affair with electronics and Ham radio - 73 - KF6IF
Mr Carlsons lab your vintage rca cr-88 is cool 😎 👌 👍
Amazing results. My unit could use your talents desperately. No one around here does this type work. That RCA 88 is a very nice radio. Have learned so much from your videos on how things work. Thanks for posting all of them.
Glad you enjoyed it Craig! Thanks for your kind comment.
@@MrCarlsonsLab You are welcome.
Wow! I play with electronics, but I will never work on such a thing. But I still love to watch your videos and it's great to see and hear how you describe what you are doing. You could have said: "I looked at the wiring" and that would be technically enough. But you describe it far more in detail because you know that is the difficult part. Great!
I’ve never seen a tube tester. That thing is cool. I remember as a kid a tv repairman coming to the house with a leather bag like a visiting doctor with a bunch of tubes and fixing our tv.
The reason the power supply filter cap has to be replaced is that it is a 3 section unit consisting of three 4 mfd oil impregnated paper caps, each rated for 500 v. When the set is put into standby, the B+ is removed from the tubes and its voltage soars high to 480 v. The old 3 section unit can no longer reliably withstand that and the dielectric begins to break down. You are correct in using polypropylene film replacements provided their rated v. is at least 630 v. Also, it is a fool's errand to try to retain the stock capacitor can because the 3 capacitors are potted in tar inside the can, making for a difficult messy salvage job.
Hi Paul. It is always a pleasure watching you working on a lot of electronic equipment, but most of all, refurbishing vintage short wave receivers. Since 1974, I have owned a Hammarland SP-600 (great receiver), which around 10yrs ago stopped working. I am looking forward to see you restoring one of those!
nice! i had an RCA way back when..very relatable.
I think this is the first project I've seen where so many tubes needed replacing. This radio must have had some serious use. It's going to be a great one once it's fully restored and adjusted
Thanks Paul...
The professional way to upgrade an old CR-88 communications receiver indeed! Your videos are both very informing & entertaining to say the least! Thank you...
Working on an IG-82 (AG-10) Heathkit Sine/Square Gen. There is one 4uf film cap. It connects from the flatness adjust circuit to the plate of a 6CL6 (104v). Based on all the info you've dropped, here and patron, new stuff (parts) are way better build, and don't over think it with replacements. I'll post pics and the community when it's completed. Thank you.
Such a beautifully constructed receiver. I love old point to point stuff.
I hope you keep all those tube boxes, they are awesome!
I wondered about that as well. I find it very difficult to throw away vintage component packaging.
Watching Mr. Carlson install the three electrolytic capacitors reminded me of the three same caps I replaced in the three AR’s I restored. At the time of these restorations I elected to take the route of removing/separating the original power supply electrolytic inner encasement from its outer metal chassis enclosure cover. I mounted the replacement electrolytics on a perfboard in the chassis opening where the originals were mounted and covered the perfboard with the original outer power supply metal cover enclosure, minus the inner capacitor encasement, so it maintained cosmetic originality.
I was able to do this without compromising the inner encasement containing the three original power supply electrolytics. Those three electrolytic capacitors are mounted in a sealed metal encasement inside the chassis mounted outer metal enclosure cover (riveted). This original configuration may not be the same for every RCA AR/CR produced but this was the way it was for the three AR’s I restored. You never know what you might run into with an AR/CR restoration. I have the original electrolytic encasements stored in my shop and still no signs of leakage from any of them. I would not recommend the method I utilized unless the inner electrolytic encasement show signs of physical leakage and at that point removal is a must. If removal of the electrolytic encasement is require proper PPE is worn as it hard to say what chemicals and/or oils lurk inside that encasement. Mr. Carlson’s method is a lot easier and faster and, as Mr. Carlson states, a lot more efficient without having to utilize that long wiring harness.
I continue watching this restoration series with enthusiasm!
Always a great learning experience when visiting you in the lab Paul. More troubleshooting awaits. Great series so far Paul!
Mr Carlsons lab your utube videos are awesome 👌 👏 👍
I appreciate that Greg!
With an old-school analog tube tester, it's always nice to START with a new tube or two in order to establish how that tester will display a healthy tube. MOST tubes on my analog tester go about half way up the good scale.. but 6AQ5 only goes 1/4th of the way up on a fresh one.
Enjoyed watching again. On to the next episode.
Nice to see that you were able to locate a connection diagram for this receiver. Looking at the old Rider perpetual trouble shooter manuals, I've noticed some manufacturers included connection diagrams. Most did not. I'm in the middle of an old Sears Model 1806, variant 2, receiver rebuild. This unit was made by Colonial. The schematic is as bare bones as you can get. It shows all the circuitry, but a lot of stuff isn't labeled. There's nothing to indicate what coils are associated with what band. The tube elements are shown, but there's no pin outs. You have to refer to a receiving tube manual. I've been doing a lot of wire chasing with a multimeter.
Mr Carlsons lab you are good at restoring vintage shortwave receivers and alignment of vintage shortwave receivers
This is gonna be a fun watch! Love the series so far
Nice capacitors !
Mr Carlson, I have used those same Polypropylene capacitors in some of my restoration work. For example I used them in restoring a 1929 Majestic 92 radio's power supply and in a 1940's HP 300C audio generator. Very nice compact caps.
An impressive unit Paul, lots of room to hang Capacitors which makes it easy. I'll be interested to follow along with your troubleshooting efforts in the next episode 🙂
Another excellent restoration video, thank you 😊
Coming along nicely Paul, thanks for sharing.
in my AR 88 the 2.7k dropper resistor to the VR 150 was faulty. There is also a lot of heat traveling down the post wires and the solder joints became dry to the VR150.
The BFO components are inside the BFO can and over time they became cooked due to being inside the can from the heat of the valve's.
Thanks, Paul. You do really nice work!
Thanks for the kind comment Robert!
Enjoyed this video very much. Especially the part where you went into detail with the schematic.
Thanks for another good one!
Glad you enjoyed it Terry!
Awesome looking receiver! Thanks for sharing this with us and have a great weekend!
Super info and classroom time Mr C.
Loved it.
Very nice to follow this restoration just love it great job Peter thanks
Hello, Mr. Carlson". It's been a while since 'I've said hello and wanted to do so, especially with this series your doing with the RCA CR-88. The time you're taking to explain in detail, steps and procedures in resurrecting this receiver is well-appreciated. Plus, you make a darn good teacher the way you explain the schematics. As a novice, I appreciate your time and effort in your presentation. Thank you again for educating me and keeping me out of the Bingo halls. Cheers my friend and stay safe.
NICE. Two memories popped in my head... One, my mother asking my dad if he had unplugged the set and him getting knock on his keaster. Mom shaking her head, chuckling and saying, "I warned you". The second was not so much a memory but I would not have been surprised if Fibber McGee and Molly came blaring out as U were tuning the dial. "Be careful with that door.... Fibber!???"
Paul, I dont remember if you ever discussed this, but how does a youngish man like yourself learn all about tube equipment? Where did you get your knowledge and build your expertise?
By the time I got into work in the mid-70's everything was already solid state so while I did learn about, for example, current limited variacs in college I never really had to apply any of that knowledge. I remember my grandparents having a tube radio when I was a nipper, the glow used to fascinate me (and scare me) but I never had the opportunity to work on anything with tubes. I live vicariously through your videos :) Thanks again, this series has been really interesting.
a great fun video to watch and learn from!
Vacuum Tubes, Inner Tubes, "the Tubes", CZcams, Tube Tops, Tube Slide, Tubular Teeth! (Moon Zappa). So many Tubes. 😂😊
You forgot the socks!
a fun project. Keep up the good work, Carlson.
👍Thanks for video. I was little surprised that you had to replace all(?) the 6SG7s. Though, I suppose many of these sets clocked up many operational hours which might explain them all being low gain.
Many of these were on 24/7, so the tube emission is very low. Common for these types of receivers.
Loving this work your doing. I remember the vfo being so smooth just like yours, happy days!
Nice video, once more Paul. One thing I wondered about though. You were happy with the new filter caps being closer to the filter coils. Less noise to be picked up (if any). However you decided to leave the old wires in. Why not remove them altogether to eliminate any potential noise being picked up?
Hi Svein. The disconnected wires will not introduce any noise, as the are just filtered DC. Thanks for your kind comment!
Loving the content, Mr. Carlson!
Great learning I understand every part Mr Carlson sir you are awesome sir thanks for sharing this video sir.
You are most welcome!
The "W must mean weak" made me chuckle! For sure, in your case, W sure did mean weak! If I remember right, W was a code for a ruggedized military tube. Which for a CR-88 would make a lot of sense. :) Great video series! If I ever see one of these AR-88 or CR-88's for a price I can afford I'll grab one. If I remember right, you've got a Hammarlund Super Pro awaiting restoration? I have been working on a military SP-200 (BC-794) for almost a year now (full restoration) and very close to firing it up! :)
You're right about tubes with a W being military grade, but that is if it's a part of the factory printed tube numbers. The W he described was hand written on the top of the tube.
Loving this series, Paul!!!
Loving the series! What a beautiful receiver. Bring it back to its full glory! :)
Wonderful content and an excellent video. That tube tester was, in of itself, amazing. Would be great to understand how it works.
I replaced the rectifier tube on my AR88 with silicon diodes. This was a bad move as the reduced forward resistance of the silicon diodes caused the first smoothing inductance to burn and go short circuit because of the higher current pulses. It also raised the HT voltage by about 20 volts. I managed to cobble up the bias circuit, but I should have left the old double diode in place.
I 💓 the new format!
I grew up in the Solid State Era, so I am surprised/shocked to see something with Tubes from long ago, working so well.
There was a time when RCA actually meant quality. Now they are just sub-par along with everything else that is mass produced
26:30 Oh come on, Mr. Carlson... It's not a bench if it's not messy. (At least that's what I tell my wife. 😅)
Great!!! to be continued... (more learning)!
OMG how did you get my dads soldering gun... :) That thing was scary.
I've used your technique to replace capacitors When I did my Heathkit Oscilloscope cleanup. It worked great and everything still looked stock and nice
Dont make us wait so long for the next one please? :)
You Very Nice Tube Miter
Well Done, beautiful work!
I would call you the Bob Ross of electrons, but Bob Ross was sort of a fraud, you are the real deal! Wish I knew 1% of what you do.
Paul, an idea for a future video would be to discuss technical issues related to those bathtub capacitors. What is the point of putting some caps in an oil(?) bath inside a metal box? Are they off the shelf parts or always custom made? Three caps in one box with two of them having a common end with a third that has its separate leads seems a rather odd design. Why not three separate caps in the box and then connecting the ends of two together?
This guy's a total control freak.
Why did they draw the tubes UPSIDE DOWN? Heh! Thanks! It helps to draw supplemental diagrams for sure! Great info as always! JC
In the words of Jack Nicholson "where does he get those wonderful toys?"
Great technical and educational skills. Shame the radio spectrum is mostly junk.
Absolutely spectacular radio I would like to find an original one but in Italy most are modified due to the different power supply
Your videos are so insightful for restoring old radios. I rarely see an older FM radio. I have a 1948 AM-FM Stromberg-Carlson (any relation?) Model 1204- 7-tube unit that I'm working on now. Any special advice you'd offer on FM radio restoration? 73 - KB4JN
I like your restaurations, but I tend to replace the "chassis" mount capacitors by remade ones. A dealer here in Germany has them, made be FTCAP. Most likely a variant of their "S series", but in the classic values like 8+8, 16+16, 32+32, 50+50 or 50+100 µF.
They are quite expensive, but available and it somehow feels better to me instead of sticking modern ones on the underside of the chassis.
Paul, have you done the National NC-300 yet? (I searched your channel but came up empty). I know it might not be universally interesting given it's a ham band only receiver with no BC band to offer the dramatic sounding first-firing-up magic from a chassis that looks like it couldn't even light up filaments (I love those moments too, btw). You've inspired me to consider restoring a 300 and recapture those days as a kid, 65 years ago, when I excitedly operated 40-meter CW!
See website for details coming out of this old radio would have confused the original users of it!
When you switched it on again I expected some old fashioned music ...
👍
Paul, if a circuit calls for an electrolytic capacitor, and you can replace it with a non-electrolytic capacitor, then why would the designers bother using the electrolytic to start with? I'm sure you've covered this previously, but if so, I must have missed it.
Why do not lace the wiring with lacing twine?
Try getting your hands in there. It was hard enough to snip the tail off the zap straps with a small clipper. All that factory lacing was done outside the chassis, (on new flexible wire.) The wire is as hard as a rock now and took heating to gently move it.
The three capacitors in the can are electrolytic, but you are replacing them with a poly capacitor.
Are you using "Metallized Polypropylene Film Capacitors" in this restoration?
Can you use these capacitors to replace old wet-tantalum capacitors in old test equipment?
Would seem Number 5 is "not" alive. :)
Ouch😅
I restore radios and most of the AA 5 sets I see have a phono jack. This Bendix I have on the bench has a 3 section filter which is isolated from the chassis. I cut the connections to the can ground and left the remainder of the filter wiring in place reasoning that if a section leaks there would be nowhere for the current to flow. I then located the recap in an open section of the chassis and wired to the set as good practice allows. Does this violate that practice?
I can't remember, but maybe the BFO is non op on BCB by design.
Hi, is part 4 video out? thanks
Enjoying this series and following along with my own receiver. Is there another way to identify tired tubes if you don't own a tube tester? There aren't many around over here
I many cases you can measure the voltages (and by this, indirectly the currents) around the tube and take quite an educated guess. For example, if they have a cathode resistor and you see that plate and all grid voltages are in spec (or higher) and the drop over the cathode resistor is low, you can be pretty sure that the tube is weak.
Great video and work Paul. A question if I may; do you think that 5 lead filter capacitor was custom built for this receiver, or would it have been an off the shelf component at the time? Seems so specific to be off the shelf. Thanks.
Does anybody know the part number or name for the hooks and tab that connect HP half rack gear together for a 19" rack mount?
Paul, is your Heathkit Tube Checker from a kit, or did you purchase it intact?
What was the capacitance of the filter caps? and can one change out all electrolytic caps with non electrolytic caps? why or why not?
I noticed that you have a bare wire from ground to #5 of the old capacitor. Keeping it discharged? If so then why not the other 2?
My error, please disregard my previous reply.
I hope the Aliens don't hear about your " Super Probe. " 😱
I wonder if this thing is full of rubber wiring like the 2 1946 RCA's I've just finished up.
I think they wouldn't use rubber wiring in commercial grade receivers but only in retail ones but , there are always exceptions.
@@hestheMaster Why wouldn't they? Rubber was a perfectly good wire covering. How could they possibly have forseen that it would be deteriorated in 80 years? Now we know the cloth wiring held up the best. But back then cloth may have been considered a hazard used in the lowly consumer-grade machines. RCA and Crosley used rubber wire. Others may have also. At the time it may have been considered superior. Context means everything.
@@totallysmooth1203 Hence me saying there were exceptions. Before the war years ( 1938 to 1941) stock of rubber covered wiring was used up and they went to cloth wires since that is what was only available until the war production board came about so only materials approved to make war products. After the war years ( post 1946)they still had plenty of cloth wiring to use. Did they also use rubber wiring? Yes, some manufacturers went back to rubber for a time.
🙏👏👏👏🙏
Hi Paul, nice restoration video and series. However there is one thing that irks me about your methods.
First, you really do a great job of retrofitting new-technology components into the old architecture. however your use of cable-ties (you call them zap-straps) is incredibly tacky to me. Instead, you should be using period-type waxed-nylon lace which is either available in natural (an off-white) or black. The lace is super-strong, and allows you to dress cables much more neatly, (close-wrapping) or that require any turns or off-branches.
Additionally, the lace will never break or become brittle, unlike cable-ties unless you buy the expensive ties (and know the difference!)
Those plastic 'zap-straps' just have to go, they are just so ugly and inappropriate--please stop using them.! Thank You! 73...
Is it for sale.$
AOA I ASK SOME THIGS PLS WRITE THE CONTANT NUMBER