How to restore vintage broadcasting equipment 102
Follow along with me as I show you how I restore my vintage Tv cameras, support equipment, and radios! This page will be an on going project. Updated every month. Keep checking back as I will add information to this page as I restore some of the vintage equipment in my collection!
Where do I start? Here is a list of what I do first to evaluate a restoration project!
For this project, I will restore to working condition a CCU (camera control unit) for a RCA TK-31A camera.
I will hope you have had some training in electronics BEFORE you attempt this kind of project. I will not teach elementary 101 electronics in this article.
NOTE: This information is the way I restore equipment. You might do it a different way. My way works for me! Please do not write me and say your way is better! This is simply a guide. Use good judgement!
Read this entire page BEFORE doing anything!
Do's and Dont's!!!!!!!!
1. Do NOT simply plug the unit in to see if it will come on!!!!!! I promise you, you will blow up some caps, and spread PCBs all over your vintage project! Some caps can be "reformed". (I'll explain this later). You can cause major damage to your item if you try to plug it in too early! This is the WORST thing you can do!!!!!!!!!!!
2. Inspect all parts very well!
3. Have a skematic BEFORE you begin your project!
4. Write down the numbers of all the tubes before you remove them!
5. Do NOT use Windex to clean the item! (More later on this)
6. Take your time! Do not rush to get it working!
HERE WE GO!!!!!
1. A complete visual inspection of the unit. I look for damaged wires, electronic components, and missing parts.
2. A skematic is a MUST here! In older equipment, most of the time I find parts labels have worn off, or mice have chewed off the insulation. Do NOT attempt to restore something without a skematic! They can be found!
3. If the unit has tubes, remove them FIRST! Write down the location and numbers of all tubes. In older equipment, the numbers on the tubes might simply wipe off with just your hands touching them! If you expect this will happen, put a piece of tape on each tube, and write the number on it.
If the tubes are dirty, gently wipe off the dirt with a moist paper towel. Avoid the area with the tube numbers on it. Windex or soapy water will take the tube numbers right off!!!!! BIG MISTAKE!!!! I have done it!
4. Remove all tubes, and store them in a safe place. If you have a tube tester, "You better, if you want to do this kind of work", test each tube.
a. Tube testing hints!
ALWAYS do a low voltage tube test! If the tube is a 6 volt, test it on 5 volts! If the meter falls discard the tube! This is the biggest mistake most repairmen make. If the filament load is high, you might get a lower filament voltage. A good tested tube might FAIL at a lower heater voltage!
Tubes CAN be found! I have over 8,000 tubes. Call ME if you need one!
5. Time to clean the unit. Be careful what you use! Some cleaners can eat the labels right off your project! Warm water is the best. I use lots of rags, paper towels, and Q-tips! Stubborn grime, can be cleaned with Windex, but BE Carefull! Q-Tips are good here, as you can get into small places, and aviod the labels.
Clean very well! Dust and dirt can damage your unit, especially if there is rat or mouse urine inside! Yes, it is true! The little buggers LOVE to nest in old equipment. They pee everywhere! Wear rubber gloves and a dust mask if you think you have to clean up rodent waste! Throw away all cleaning materials ASAP after cleaning! Avoid areas with paper labels. Once gone, they can't be replaced! Don't put tape over them either! Be careful when cleaning old paper caps. The writing might come off! Also tube numbers printed on the chassis could be gone and you will not know where to put the tubes back! (Here is where that skematic helps)!!! I normally write all tube numbers with a pencil next to each tube!
6. Checking eletronic components.
Here is where you have to be a do-it-yourself-tech!!!! If do you not know what you are doing, BE CAREFUL!!!!!! The test equipment made today is very easy to use! All you need is:
a. A digital Multi tester
b. A capacitor in-circuit ESR Meter
c. A good scope
d. Soldering iron
e. Simple tools
g. Spare parts, (oh-oh) You have none!!!! More on this later!
h. TIME and Patience!
Here we GO!
1. Check all tubes first. Throw away all weak or low filament tested tubes.
2. Next, check ALL caps! Every one! Start with the Electrolytics. The new ESR meters will check the caps in-circuit! Follow directions that came with your meter. Do NOT use one of the old capacitor testers. They are NO GOOD! Buy a ESR meter, or forget the do-it-yourself restoration! All caps can be found! Check the links at the end of this page for places to find spare parts!
3. Check all wires. Every connection! Pull on it, look for bad solder joints, cracked insulation, or shorts. Replace ALL bad wires! (You might have to do some splice work here).
4. Look at all electronic parts. All resistors, caps, chokes, tube sockets, etc. Look for shorts, bad connections, etc.
5. If you have the information, take resistance measuremants on all transformers. (If you can't do this, don't worry, after you fire the unit up, you can make voltage measurements then).
6. You should not have to test resistors unless they look burnt, or have cracks in them. I find most will still work!
7. Check all diodes.
8. Check all Chokes.
9. Clean the case. Knobs, dials, etc. Be careful NOT to wipe the numbers off. Replacements can be bought. Check the links at the end of this page.
10. Replace the power cord if brittle, or cracks can be seen.
11. If your unit has any motors, or fans, take them out. Open them up, clean out all grime, oil when needed. Clean the brushes.
12. Do a final cleaning inside.
13. Replace the tubes.
14. Sometimes the power cord in missing. You can make one with a new cord, and if the female connector is different from anything you have ever seen before, use insulated clip leads to connect it up. Watch for shorts!!!!
15. If the unit requies a seperate power supply, (and you are lucky enough to have it) restore it in the same way way as explained above.
16. If a external power supply is needed, you must have your own bench supply. I will not go into this. You either know how to use one, or you don't! Be aware of the current draw here!
17. Do not worry about fully restoring the case, paint job, etc. If the unit fires up, them you can take that step later!
18. If you do need spare parts, there are many places you can buy them. Many on the internet. I will have links to some great places on this page soon.
Lets fire it UP!!!!!!
Now we are almost ready to turn it on!!!!!
Important!!!!!! Re-Check everything! Make sure you have put all the tubes back in the correct place, there are no shorted wires, etc.
1. Read the manual! Most have first time set up information. Where to set the controls, etc. On vintage tv equipment, there are settings for every knob for first time operation.
2. Here is where you need the Variac. Get a good one. You can't turn on equipment without it! If you have a current meter, USE IT!
Do NOT simply plug it in the wall AC outlet!!!! DUMB!!!!!!!!!!!!!!!
All your restoration work will be lost if you rush these next steps!
3. Find the pins on the unit that supply the AC filament voltage. Clip lead a AC power cord to these pins, and slowly bring up the 117 volts AC to the filament transformer ONLY! You want to "cook" the tube heaters for hours FIRST, before you supply high voltage to the unit! Look at all the tubes. Turn out the lights. Make sure ALL the tubes are lighting up. Non lit tubes, could mean a bad tube socket. Twist the tube a bit to see if the filament lights up! Replace the socket if you have to.
4. Go have lunch! Let the tubes cook! After you have taken a long needed rest, turn off the filament voltage, take all the tubes out, check them again, do a low voltage test, and replace any bad, or weak tubes! This sounds stupid, but I have found bad tubes later, that tested good before I let them cook in the unit!
5. After the filament warm up test, you are ready for the SMOKE TEST! Yes, thats what we call it! Hook up the Sync generator if it requires one. Make sure you have ALL the required pulses! Do NOT fire a vintage piece of equipment up without the correct Sync pulses connected!!! Hook up the main power cord, turn on the Variac, and start with about 25 volts. Let each step cook for about five minutes. Go up in 5 volt steps. I don't care if this takes ALL DAY! Do NOT rush this! Here is where you (re-form the caps)!
This means bringing up the voltage SLOWLY to all the caps. Even some bad caps "could" become good again if you re-form them!
As you SLOWLY bring up the voltage, look at the unit and if you see any of the following, turn OFF the power!
b. Hissing sounds, (this can be bad! Its the sound of a electrolytic cap leaking) If this happens, you might be leaking PCBs all over the place! If you hear this sound, you may NOW PANIC! Turn off the power, and RUN like hell! Do not breath, open the windows, and close the doors to the rest of your house. I have even fired up suspect equipment in the back yard, if I thought caps might blow! You have heard about PCBs. Its true! You do NOT want to breath this crap in your lungs. It could cause Cancer many years later.
After you have aired out the shop, put on a mask, and gloves, and take the unit outside. You can safely clean it all up, just do not breath in the fumes, or touch it with your bare hands. Better be careful now, than sorry later! I have had a few caps explode on me, and I have taken my time cleaning up the mess. Scrub all areas with soap and water. Dispose of the cleaning items safely. The PCBs are invisible. Good LUCK! All I can say here, is, use good judgement. Don't be scared, just use common sense! I am not the PCB expert here. Just be aware, this stuff can be harmful!
c. Glowing tubes, really bright RED or BLUE is not good!
e. FIRE!!! Not good either!
f. Nothing! Sounds weird, but after about 90 volts, SOMETHING should be happening! ( Did I mention to check the fuses)!!!!!
g. If you take your time, you should see the tubes lite up, and if its a video camera, the CRT should be lit up. It might be rolling, horz or vert, that is ok. It should be better as you bring up the voltage.
On old cameras, make sure the Beams are OFF!!!!!!!
h. IF it made it this far, continue bringing up the voltage until you reach full power. LET it cook for a while! A LONG while!!!!! Again, watch for problems.
Remember, this is NOT Electronics 101. I hope you "kinda" know what you are doing.
If you are working on a radio, or non camera piece of equipment, the same steps should apply.
If the unit dies a few minutes, or hours after you get it working, don't throw it across the room. Simply go back to step #1 and start all over again! I do it, and so can YOU! A lot of the parts might have been sitting for 30 + years or MORE! Yes, reforming the caps really helps, but they still can die on you!. Its good to check the caps again with your ESR meter after you have run the unit for a while.
The TK-31 CCU un-restored.
Lots of grime, some old bad caps!
The same CCU, restored, with NOS caps! I got lucky here, I did not have to put Orange Drops in this unit. It looks better with original type caps!
The other side, not too bad, but needed some cleaning up!
All cleaned up, tubes tested, bad ones replaced.
Some of my test equipment. I have a few tube testers. The oldies work just fine!
The Multi Meter is on the left, the Cap ESR meter is in the center, the current meter is on the right.
Some of the caps I use.
You MUST have a Variac!
Here we are!!!! The RCA TK-31A CCU working! Easy as PIE!!! HA!
Stay tuned, links to vintage equipment companies coming soon!
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Last modified on Sunday, May 05, 2002