Well, you must be interested...you made it to page two.... now we get to the FUN STUFF .... let's make a radio !!!!
LET THE FUN BEGIN
HERE is a shot of the stack of radios I ended up with. We are starting with the lower right unit.
INTRODUCING THE LOWER RIGHT.... S 38 A SERIAL AB-362267
This unit was not in too bad of shape. I decided to just replace caps, and align if possible. We will also try to salvage the cabinet as is.
THE UNDERSIDE OF THE S-38B REVEALS THE LARGE ELECTROLYTIC CAP IS NOT ORIGINAL . EVERYTHING ELSE LOOKS FINE AND NO OTHER MODIFICATIONS WERE NOTICED. A REAL GOOD CANDIDATE FOR A FIRST PROJECT
THE TOP CHASSIS IS ALL IN TACT WITH NOTHING MISSING EXCEPT FOR THE MAIN TUNING CAP DIAL CORD.
This is the best cabinet I got. As you can tell, it is in "fair" shape. We will see how it cleans up.
The cabinet cleaned up well. I used ammonia and water and cleaned inside and out. I then used automotive rubbing compound . Be careful around the lettering !!!! Following that, a liberal coat of "Turtle" wax finished it up.
TIME FOR THE ELECTRONICS !!!
THE FIRST THING YOU NEED IS THE SCHEMATIC !!! They are readily available on the web. However we have made it easy.
S-38
S-38 A
S-38 B
S-38C
S-38 D
S-38
E
I HOPE YOU HAVE A HIGH SPEED CONNECTION !!
I don't usually include links on my web sites, as they never stay accurate, but I did find a few that were inspirations to me.
COMPLETE OFF THE CHASSIS RESTORATION
REPAIRING ALL AMERICAN FIVE RADIOS
AND FOR FUN.......
DANGER WILL ROBINSON !!!!!!!!
Please don't be tempted to turn this thing on yet. If that large cap is shorted, you may lose a tube or another components. Besides, we haven't talked about the isolation transformer yet.
HERE IS AN ISOLATION TRANSFORMER THAT WE WILL BE USING
LEARN HOW TO BUILD ONE HERE
Take off the knobs. The set screws on these knobs IS NOT an Allen wrench !!! You must use a 5 sided "spline" wrench. They are available at hardware stores. I bought mine on EBAY. Do a search for Hallicrafters and you will find them. If you use an Allen wrench, you will probably mess up the screw and never get it out. And just as I say that, I find one screw that the "spline" wrench doesn't fit. I Had to use an Allen wrench..
You might want to put a drop of penetrating oil on the set screws of each knob. Let it soak in overnight, before trying to remove the knobs. The set screws may be frozen in place and you might break them if you use too much force.
I use a glass jar to store all the knobs and screws and such. Use what ever works for you.
Remove the radio from the cabinet. If it has a bottom and back, remove them. the chassis is held in place by 4 screws on the bottom and the front panel screws. They hold the red slide switches.
THE FIRST THING I do is take a paint brush and brush away as much of the dust and dirt as possible. Do not try to get it all squeeky clean, just get the bulk of the dirt. If you have an air compressor, use it as well...
NOW CHECK THE TUBES to make sure the proper tubes are in the proper socket. I found several that were INCORRECT
We are using our S-38A as an example....Please consult your diagram
LETS CHANGE ALL THE CAPS !!!
FOR GOOD INFORMATION ON CAPACITORS SEE http://antiqueradio.org/recap.htm GO READ IT...
OK...WELCOME BACK ...
A WORD ABOUT THE CAPACITORS. We are ONLY changing the round "orangish" type... These always go bad. The square type at the top of the picture are Mica caps and should not need replaced. Same with the resistors, but we will talk more about those soon..
THE FIRST THING WE DO, is make a drawing of all the cap locations... If you remove one, then get distracted,. you may forget where it goes..... You should also consult the schematic !!!! Make sure the idiot with the phone jack and knob (see above) didn't change one with the wrong value !!!!
Changing the caps is really easy. I prefer to remove the old cap entirely, RATHER THAN cut the leads and attach the new cap to the old leads..... I find that by using "solder wick" I can remove the caps fairly easily. (make sure you make a drawing of the cap location) Be extra careful with the tube sockets. If you bust off the connection, you may have to replace the socket...Not a fun job
Make sure you check your work, and there are NO leads touching that shouldn't be.....
One thing to look for when changing caps. Many times the makers will use the long cap leads to go to more than one place. They may feed them thru a tube socket terminal, then on to a ground. When this happens, just cut the lead at the first junction and wrap the new cap there.
HINT: YOU CAN USE A "TOOTHPICK" TO MAKE A HOLE IN A TERMINAL.. (SOLDER WON'T STICK TO IT) JUST HEAT UP THE JUNCTION AND "POKE" THE TOOTH PICK THRU.
Here is the chassis following capacitor replacement. The large RED cap, is the electrolytic for the power supply. The original also included the cathode cap for the audio output tube. I used a three section cap for the power supply, and a separate cap for the output tube. This capacitor came with a "sticky mount" attached. You simply peel off the bottom paper and "stick" the cap to the chassis. Don't do it. I have found that they will not stick on the metal for very long. Tie it down.
There is plenty of room for the small cap. The output tube is on the bottom second from the left... Notice the small blue component....that is the small capacitor. On the right : typical caps removed from an S-38
The problem with the picture on the left is : The new capacitors LOOK NEW. Perhaps you want to leave the "origional look" There is a way. You can "re-make" the capacitors. The small caps can be "re-stuffed" into old shells. The power supply capacitor is another challange. After a couple of tries, I decided they were too hard to take apart and re-stuff......so I made new ones !!!!
FIND OUT HOW TO DO IT HERE
Let's take a look at the schematic.... you have one right ?? Please follow along.....
See how the 120VAC comes in ? One side is grounded. C 36 is a .25MFD that goes from the hot side to ground... If that cap shorts, you "should" trip a breaker. It is a good idea to have a fuse in this line. (more on that later, as well as some ideas for making this radio safer) .... For now, we want to restore it to original condition, BEFORE making any modifications. Coming off of Pin 8 on the 35Z5 rectifier tubes is a 470mmf cap. It is MICA and should not need changed. Take a look at the 3 resistors that is across the Electrolytic cap. If they are cracked or look like that have seen some serious heat, you may want to change them as well. Also check the 330 ohm resistor across the indicator lamp... It is also a good time to check the lamp as well.
Now is also a good time to check the continuity of all the tubes. The heater (of filaments) of the tubes are IN SERIES ... Like the old style Christmas Tree lights, if one tube opens THEY ARE GO DARK..
Now lets check the chassis insulators !!!
Keep in mind, we MUST keep the case ISOLATED from the chassis. Look at Picture 1 & 2 . There are 2 sub-assemblies that hold the front panel slide switches. These are isolated via a rubber grommet. They are installed with rivets so you may have to drill them out. The rear of the chassis is isolated with standard rubber grommets.
To string or not to string..... Some people do not re-string the tuning capacitor if the string is not broken. If you plan on using this radio, I suggest you re-string NOW. It will save you lots of frustration later..
THIS GUIDE IS ALSO AVAILABLE ON THE SCHEMATIC.....YOU DID DOWNLOAD ONE, RIGHT ??
COMPLETED S38A CHASSIS.... CLEAN CHASSIS WITH AMONIA & WATER (CAREFULLY) BUFF WITH 0000 STEEL WOOL.....
A LITTLE RED SPRAY PAINT ON THE POINTER... READY FOR THE CASE !!!!
VICTIM NUMBER 2 AN S-38B
A COUPLE OF OBSERVATIONS ON THE B VERSION. It looks like Hallicrafters got the message about insulating the chassis. On this version, the tuning shafts have been changed from metal to a non conducting rod. AND the volume control and band switch are isolated from the main chassis. So BOZO with the 1/4 inch set screw (see above) may have survived if his radio was a "B" version.. A "cardboard" cover has been added to the back of the unit to help insulate the rear from "hands" reaching around the radio. However, the "rivets" that hold the cover in place defeats the whole purpose. They have also added a "cheater" cord to the chassis. A connector that only works when the back cover is installed...This unit is very dirty but I see no modifications to the unit and it should clean up and restore well...
ANOTHER difference in this unit was the filter capacitor. (C-14b) It has been increase from 40mfd (on the A version) to 60 mfd. I used a 47mfd with no problem.
RESTORATION OF THIS RADIO WENT VERY SMOOTHLY. Following the replacement of all the capacitors, the unit was fired up slowly. Nothing happened !! Checks fount that the ON OFF switch was bad, so it was temporally jumperd. Voltages looked normal but the audio was very low. Turning the volume control up had NO effect on the audio. The control did not "feel" right so a replacement was installed. The new POT also solved the switch problem and the audio was restored to normal. Preliminary checks found stations on all 4 bands. Alignment and cabinet refurbishing to follow.
BEFORE AND AFTER..... THE SECRET HERE IS "SHOE POLISH" .... CLEAN THE CABINET WITH A LIGHT CLEANER (AMONIA & WATER)...THEN APPLY A THIN COAT OF BLACK SHOE POLISH.... IT WONT HIDE THE MAJOR DEFECTS, BUT WILL FILL IN SMALL SCRATCHES......THIS METHOD WORKS WELL WITH CABINETS IN GOOD SHAPE. MOST OF OURS WILL NEED REPAINTED. WE ARE TRYING TO GET ONE SET OF S-38'S AS ORIGINAL AS POSSIBLE....
LETS PAINT THE POINTERS !!!
Notice the "safety glasses !!! The pointers we "wire brushed" before painting. Never use power tools without "saety glasses !!
Minor touch up on the alignment was all that was needed.
Back in the case it goes... Make sure you check ALL the insulators and make sure they are properly installed...
This rig really sounds good, and is ready for the display case..
WAIT !!!!! we forgot to talk abut cleaning knobs !!!!
Soak knobs for a couple days in dish
soap
USE A TOOTHBRUSH TO SCRUB OUT THE DIRT...oh, by the way, don't drop the knobs on the floor......they will break.. extremely fragile....
finished !!!!
here it is !!!... with back and bottom.... MAKE SURE the insulators are installed !!!!
LET'S TAKE A LOOK AT SOME OF THE OTHER CANDIDATES FOR RESTORATION......
This first S-38 is NOT GOOD. We see MAJOR rust on the chassis as well as the tuning capacitor. If you look carefully at PIC 3, you can see where the alignment caps are ALL rusty. Also the OSC transformer looks damaged. This rig will take a MAJOR off the chassis restoration. It's too bad, as the case in in pretty decent shape We will set it aside for now.... lets look at our second candidate :
Well, this one isn't much better. MAJOR rust. CASE has been repainted. This one is also being set aside... We only have one more S-38 in the pile.
This by far the best in the bunch. I think if we take the cabinet from number 1 and the chassis from number 3, we might end up with something. HOWEVER, we can't do that as these are different versions . Number 1 is the smooth black version, while this one is the wrinkle black. Under close examination, you can see that the BFO tube is in a different spot (closer to the tuning cap) Number 3 IS a different version. But I think this cabinet can be cleaned up. I don't see any major mods under the chassis. There is some rust on the chassis, but it looks cleanable.
FOR A LOOK AT THE RESTORATION PROGRESS ON THIS RADIO CLICK HERE (UPDATED 3-09)
We now have an A & B version completed and on the shelf for use and display. Let's continue with out FIRST complete "Off the Chassis restoration. An S-38C
S-38C OFF THE CHASSIS RESTORATION
As you can see, this one is NOT GOOD.... As bought on E-bay for parts, this cabinet needs repainted. The chassis is pretty dirty and rusted.. The first thing to do after removing unit from case , it to drill out all the chassis sub-assemblies. Also remove all the tubes sockets, and all terminal strips. Drill out the slide switches and remove the tuning shafts.. MAKE SURE you save ALL the components and take pictures or make drawings of EVERYTHING. Taking that time now will save HOURS later. This is where a digital camera really comes in handy. Strip this chassis down to bare metal. Clean it well. Now you don't have to worry about what kind of cleaner to use,. You can't harm it. Once it is clean you can either sand blast it, or sand it. Don't sand it glossy smooth. Now you have a choice to make. Either paint the chassis or have it re-plated. I chose to repaint for this one. I found some "Hammertone" paint from Rustolem that I wanted to try... Do not paint the under-side, just the top. We may re-plate one later, as I learn more about it. This is what makes this hobby so much fun, you get to learn NEW things. Like using Shoe polish and safety glasses, AND TOOTH PICKS...)
Chassis has been cleaned , sandblasted and painted.. New Tube sockets... Ready to re-string the tuning and start wiring. Interesting to note that on this C, they have gone back to the metal tuning shafts and the band switch and volume control are no longer isolated from the chassis
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02/24/09