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This is something I've been thinking of offering for some time now as I have been learning and developing my skills, abilities and knowledge for more than 50 years. Much was learned on my own, some from others along the way. So on this page I'll share these  (for what they are worth) with those that are interested. I do not claim to have all the answers or imply that I know it all or the ultimate expert. Some may disagree with my procedures and methods. What I offer is what has worked for me and some of what I suggest may be considered novel. New tips will be added as time permits. Those of you that wish to contribute, feel free to contact me with your tips and if used, I'll give appropriate credit.

Some of these tips require some basic knowledge of electronics to understand. In order to service or repair something properly, you not only need to have certain skills with your hands, but you must first understand how it works.

With electronics, like any other technical field, it takes years to become a properly skilled technician whether it's with old radios or modern technology. There is no crash course that will make you a overnight expert. There are many out there that learn about the basic things that fail most often (like the electrolytic capacitors and other capacitors that are constructed from paper and foil). Replacing these items will often bring the radio back to life but beyond that if the radio fails to work properly, they are lost as they do not know how to troubleshoot. I call these guys memory technicians or electronic mechanics.  Without an understanding of electronics or how something works, it's impossible to trouble shoot a serious problem. So I suggest to these folks; find an old course in basic electronics and radio repair, study it, learn the theory of how a radio works. It's not that hard and very rewarding when the time comes to repair, restore or troubleshoot a problem.

If you are seriously interested in learning about radio, I would start at the beginning and first learn basic electricity, then basic electronics. Afterwards you should find an old vintage course that deals with tube technology and radio repair.  As stated above, many of the tips I give require a basic understanding of electronics. So if you don't understand basic electronics, please don't ask me to explain. For the non theoretical issues, feel free to ask if you have questions.

This is a new endeavor and I will be adding subjects as time permits. As this page grows, I'll categorize and alphabetize them. Other than the first 2 or 3 tips, the subjects are not in any particular order.

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Tip #1 Always do this first!

This first tip is so simple, yet extremely important and in my opinion the most valuable. It's usually not included in most courses in electronics. I learned this very early as an apprentice TV repairman at the age of 15 from Jake Rodman (Supreme Radio & TV service), a first class TV technician in my home town of Ashland, KY,:

Always give the piece you are about to service a good visual inspection. Give it serious scrutiny, not just a glance or quick once over. Be diligent, give the piece (or pieces) a good cleaning, look between the components, the tuning condenser, remove the tubes, inspect the sockets. Look on the underside for sloppy workmanship done by a previous technician or mechanic (this is often the source of many problems). A great deal can be leaned by noticing the physical condition of the chassis. For example; a burned resistor, blown-out capacitor, sloppy soldering, a bundle of wires all globed together by the previous mechanic who just clipped off & left the leads & wires of previous replaced components. Look for material leaking & oozing from a transformer or canned component. Notice anything that looks out of place.

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Tip #2 SAFETY ON THE REPAIR BENCH!

Always use an isolation transformer when working on an AC/DC radio or television (sets without a power transformer). Failure to do so can result in a serious electric shock plus damage to your test equipment when you hook up the ground lead to a "hot" chassis.

DO NOT plug your test equipment into the isolation transformer, just the radio. I've seen folks wire their isolation transformer to a plug strip with all their equipment plugged into it and wonder why their "scope's" ground lead went up in smoke when they connected it to the radio chassis. If all your equipment is plugged into the isolation transformer, then nothing is "isolated"! Only the radio (or television) under test should be plugged into the isolation transformer!

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Tip #3 Line Cord Polarity! THIS IS AN IMPORTANT SAFETY ISSUE!

You may get a minor shock on most series strung (AC/DC) tube radios as one side of the chassis is usually connected to the line cord either directly or by a capacitor. In the case of the type that is connected by a capacitor the shock is normal and not deadly unless the capacitor is shorted. You can get a deadly shock if the "HOT" side of the line cord is connected directly to the chassis (some early sets were!). Visually check the wiring, that's the best way to tell which side of the line cord goes to ground (or the chassis). Some ground buses float above the chassis. No matter which side of the chassis the line cord connects to, you can still get a shock because the o/o switch will determine which way the chassis comes to the line cord potential (on, one side off, the other) Some of those sets were deadly as one side of the cord was tied directly to the chassis.

The only safe way to prevent a shock is to make some minor wiring changes to the set so the neutral side of the line cord is connected (with a polarized plug) directly to the chassis (or common if it's floating above chassis potential) and wire the "hot" side to the switch. This way the neutral or ground is always at the chassis or "common" potential and you wont get shocked (as long as the polarized plug is plug into a correctly wired socket. You will have to alter the chassis wiring a little so you are switching the "hot" side of the AC line into the circuitry and not the chassis or "common".

When working on these AC/DC series strung chassis's (no power transformer), always use an isolation transformer to prevent electrical shock or destroying your test equipment. Plug only the radio into the transformer, not your test equipment. If both are plugged into the transformer, your equipment can still be damaged depending on it's polarity with respect to the radio chassis.

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Tip #4 DON'T ..

PLUG THAT OLD RADIO IN!! Click here for this tip.

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Tip #5 SAFETY!

Never stick both hands into a live radio or TV cabinet or the chassis. Always disconnect the power cord, don't just rely on the on/off switch to turn off the power. Discharge the high voltage in a TV set before handling the CRT or HV components. Do it several times as sometimes in some early TV's the CRT will retain high voltage and recharge itself several times after being discharged. This is because it was not fully discharged the first or second time due to internal resistance of the anode.

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Tip #6 Cleaning old wood radio cabinets

If it's really, really dirty, first remove the insides (chassis). Then vacuum and clean it with care. The procedure to use will depend on what it's contaminated with. If it's just household dust, a powerful vacuum cleaner (with crevice tool attachment) and small, stiff paint brush is all that's needed. If it's caked with rust, crud and or rodent debris, that's a more serious matter. For normal cleaning, the cabinet should first be wiped down with a cloth quite damp with household ammonia diluted with water (about 50/50) being careful not allow the liquid to soak into the wood. This will get rid of the water soluble contaminates. Then wipe dry and clean again with paint thinner or cigarette lighter fluid (NOT LACQUER THINNER!). When dry, wipe it real good with Scots "Liquid Gold", wipe down and use a good furniture polish such as "Oz". Sometimes this is all that's needed.

If the finish is not satisfactory, looks dull or maybe has been sun bleached, I would treat the finish with "Mar-A-way" (a product I use). After using according to directions apply a good furniture polish.

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Tip #7  Spiffing up old wood radio cabinets

If after doing as I suggest above and there are minor flaws, scars and surface scratches that show, here's how to make the cabinet look better without a re-finish job.

Minor sun bleaching and surface scratches (scratches that have not penetrated into the wood).

1st, I would treat the finish with "Mar-A-way" (a product I use). After using according to directions apply a good furniture polish.

If still not satisfactory, one more thing can be tried and that is an "amalgam", I make my own by mixing equal parts of Gum Turpentine and Boiled Linseed oil. This is best done in small areas (4 - 6" square) using "0000" steel wool, soaked with the "amalgam", rubbing in a circular fashion. Do a section at a time until the entire surface is done wiping down after about 20 passes for each section. When all done then repeat the process with a soft cloth. Then do the same again, this time with long strokes across the entire surface following the grain pattern.

2nd, after the "Mar-A-way" treatment and if you are pleased with the results, use a good furniture polish such as "Oz". If there are still scratches that show, you can use a felt tipped pen that's made for this purpose. These come in a variety of colors and there are a number of brands on the market. Not all of these brands work all that good. The two best I have found are the "Mohawk" brand, second best is the "Scratch Fix" pens from the Miller company. Don't waste you money on the "Minwax" brand, I find these to be vastly inferior. Keep in mind that if the scratches go through the finish and into the wood, you can't make these go away without the efforts and expertise of a wood re-finisher or finish repair. Finish repair is very specialized and I will not get that serious.

3rd, If still not satisfactory, one more thing can be tried and that is an "amalgam", I make my own by mixing equal parts of Gum Turpentine and Boiled Linseed oil. This is best done in small areas (4 - 6" square) using "0000" steel wool, soaked with the "amalgam". Rub vigorously in a circular fashion  a section at a time until the entire surface is done. Wipe down (remove the excess)  after about 20 passes for each section. When all done then repeat the process with a soft cloth. Then do the same again, this time with long strokes across the entire surface following the grain pattern.

Crazing (the finish is alligator'd but still intact). Treat as suggested in step 3 (above).

If the above does not leave the cabinet looking presentable, the only thing left is to strip it and re-finish.

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Tip #8  determining capacitor voltage ratings

Many of the old schematics did not include the voltage values. It's pretty easy to determine the voltage ratings by the type of power supply.

If it's a power transformer'd unit, then go with 450 for the filters and at least 400 volts for the B+ by-pass & coupling caps and 200 volts for the cathode by-pass caps. It does not hurt to overvalue the voltage rating a bit, but never under rate them.

If the radio has series strung heaters (no power transformer), then 150 - 160 volts is the typical rating of the filter caps, coupling & B+ by-pass should be at least 200 volts. I would still recommend 400 - 600 volts for these as the lower voltage capacitors are hard to find in new stock (they are usually rated at 630 volts).

Most new old stock paper capacitors will be leaky and I would not recommend using them unless you have good capacitor checker that will apply full rated voltage to test for leakage.

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Tip #9  Testing capacitors (can you check 'em in circuit?)

Some use an ohmmeter to check capacitors. This test will certainly reveal a dead shorted capacitor, it will not tell you if one is breaking down under voltage.

"In circuit" capacitor checkers have limited reliability and usage as you cannot check for leakage with such and instrument. To check for leakage requires applying the operating voltage, the Heath IM-11 or IT-28 can apply up to 600 volts to the capacitor being tested. You can only do this with one end of the capacitor disconnected.

So the answer is you can only check for capacitance with an "in circuit" checker. Most problems with capacitors is due to leakage current caused by a breakdown of the capacitor's dielectric. Such leaky capacitors will often pass with flying colors a "capacitance" check as they only break down when the operating voltage is applied.

I use and recommend the Heath IM-11 or IT-28 and the Sencore LC53 "Z Meter". If you want a more serious analyzer, I would recommend any of the Sprague "Tel-O-Mike" units that have been restored and calibrated.

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Tip #10  Removing the potting material from transformer & capacitor cans (the black* stuff that looks like pitch or tar)

Remove the container from the chassis and place it in the freezer over night. The potting material will become very brittle and you can bang around on the can and often the entire contents will just fall out. For the more stubborn ones, you can tap or chip the stuff away with a screwdriver until it's loose enough that the whole insides can be dumped. Be careful and don't gouge to deep in the can as you may damage good components such as a transformer or choke. Do it outside or over a garbage can, that stuff will get on your floor and shoes and if you think getting the stuff out of the can was a problem, you have an even  bigger one removing it from you carpet. When you tap on the can use a wood block between the hammer and can so you don't ding it up.

* there are different materials used for "potting" components and other colors will be found. Some have fairly low melting point such as "Pine Pitch" that is amber in color. This can be melted with a heat gun, saved and reused.

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Tip #11  Early radio antenna & volume control problems

Early radio receivers made from the early 1920's to mid 1930's work a bit different than later radio sets. All required a "long wire" antenna and few during that period had "automatic volume control". In the early days a typical radio installation required an antenna strung up outside on poles or from the house roof-top to a barn, tree or pole of some kind. Radio stations during the 1920's & early 30's where often far away and to receive them, the higher and longer the antenna, the better. A typical antenna installation was about 100' long for good reception of distant stations.

If there was a local station in your area, this was another problem because unlike modern radios (or those made after the mid 1930's), there was no "automatic volume control". This meant a strong local station would boom in, usually overloading the radio often to the point that you could not turn down the volume. The solution to this was to remove the antenna altogether or shorten it substantially. This is still problem today when operating some  vintage radios. You'll find local stations will "boom" in at very loud volume and more distant stations require advancement of the volume control. This is normal for this early technology. These days with so many local stations a wire 15 -20' long lying on the floor or stuffed out of sight between your carpet and base board will allow you to pick-up local stations.

If you have an attic, a wire strung up there will work just fine for distant reception. Another option is to purchase a modern devise called an active antenna, it uses a telescoping rod and has an amplifier built into the base that works as a "long wire" antenna. I have not used such a devise but see them advertised (I believe Radio Shack had them at one time and may still). I have heard positive feedback from those that have used them.

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Tip #12  Automatic Volume Control (AVC) what does this mean?

In the early days of Radio (early 20's - mid 30's), radio receivers did not have "Automatic Volume Control". So when tuning one of these radio sets a strong local station would come with loud, often with uncontrollable volume. Then if you wanted to listen to a weak distant station, you had to first turned up the volume, sometimes to it's maximum setting. If you forgot to turn the volume down when tuning back to your local station, your speaker might want  to "jump out of it's cabinet".

This problem was solved by improvements in the tuning circuits and the addition of a circuit called AVC (automatic volume control) or  AGC (automatic gain control). This provided a fairly even volume level throughout the tuning range. Extremely weak stations, however would still require an increase in manual volume control as AVC operated within a certain parameters and it's function would drop out when the signal dropped below a certain level.

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 Tip #13  Testing Vacuum tubes

 is there and "NOS" test?  < click

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Tip #14 Checking your Phono amp & cartridge.

Here's a simple test to determine whether a no (or weak) sound is the electronics or your cartridge.

Lift up the tone arm so you can view the underside, locate the two small wires that connect to the cartridge holder and make sure they are connected to the holder.

Then turn on the unit and turn the volume up to listening level and with a small screwdriver of other small, narrow metallic object such as a nut pick, while holding this object in one hand (the arm is metal so don't hold the arm with your other hand or this test may not work) touch each wire connection to the cartridge holder (one at a time and don't short them together and not to worry, you won't get shocked). If the amplifier's electronics  is working, you should get a loud hum when touching one of these wires. This loud hum should increase and decrease in volume level when the volume control is turned up or down, it should be quite loud at the high volume setting.

If you get only a weak or slight sound, chances are the phono's amplifier is not working and you will not hear any controllable sound from the stylus. If you hear the hum I described, either the cartridge is defective or there is a contact or wiring problem to the electronic amplifier.

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Tip #15  Noise or sound "cut out" when tuning in stations

The problem with noise and static when you tune can be caused by one of 3 things:

1) Dirty wiper contacts between the rotor plates and shaft (this is the small metal clip that makes contact with the rotating shaft of the tuning condenser and frame right in the middle of the tuning condenser, it will have two (or more) of these depending on the radio.

2) The plates of the tuning condenser may be bent and contact is occurring between the movable and stationary plates.

3) "crystal whiskers" may have grown between the plates on the tuning condenser. These are difficult to remove, you can determine this by using a loupe or magnifying glass and take a close look at the condenser. If this is the case I can give you instructions on how to deal with this problem. I'll publish more info on "crystal whiskers" later.

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Tip #16  Cleaning noisy controls, poor or open switch contacts

These problem can usually be corrected with "Craig DeoxIT D5" if applied properly.

DeoxIT D5 is very effective but a bit expensive, so don't waste it by bathing your switch or control in it, it is not meant to be used a washing agent. Using to much can be detrimental as the residue will attach contaminates and can create a short or have a semiconductor effect. It works best with a tiny amount placed in the proper place. Many controls and switches have internal access if you know where to look. Many are sealed and in order to clean them you must either take 'em apart or carefully drill a tiny hole so you can squirt a whiff of "DeoxIT" inside. One must be very careful when drilling the hole because if you don't, you'll ruin the control or switch.

Here's how I do it:

Start by using the tip of a hypodermic needle (.027" OD). Break it off of the syringe fitting and file the sharp end blunt so you don't stick yourself. Then force one end into the plastic tube that comes with the "DeoxIT".

Now you have tip that will fit into tiny areas. View the image I've created so you can see the areas where the "DeoxIT" can be squirted (remember use a very small quick squirt). Once your sure you've got the stuff inside the control or switch, work the control throughout it's rotation a few times and work the switch on & off 10 - 12 times. I've found that unless the contacts are broken, burnt or damaged, this method will restore proper operation. A good switch should measure "0" ohms (in the on position) if working properly.

With toggle switches, place the switch so the toggle is straight up and give it a squirt downward so it gets into the bottom of the switch (where the electrical contacts are). Then toggle it 12 - 15 times.

After you have  successfully restored the switch to proper operation, I suggest you then blow I out with a few squirts of canned air to remove any excess "DeoxIT".

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Tip #17  SOLID STATE REPLACEMENTS FOR HICKOK TUBE TESTER'S TUBES?

  Click here for this tip.

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Tip #18  Deluxing or "Spiffing Up" a wood radio cabinet.

You have a wood radio cabinet which could be real wood, wood veneer or a "Faux" or "Photo Finish". It looks pretty good but want to make it look better without re-finishing it - What To Do -

First, give it a good cleaning. There are usually two types of crud on an old radio cabinet; (1) greasy, waxy stuff from household contaminate, candles, dirty oily fingers etc. (2) foodstuffs (again from dirty fingers, kids or just plain slobs). Different cleaners are required as one wont have much of an effect on the other. Here's what I have found that works very well:

(1) Clean off the water soluble stuff with a damp (not soaking wet) cloth with an ammonia based cleaner. This works on the foodstuff contamination (the remains of the peanut butter & jelly sandwich for example). Be careful not to get the surface too wet, you don't want to let the cleaner soak into the wood.

(2) Then for the waxy, greasy film, I've found that cigarette lighter fluid (or paint thinner) works best on this household stuff that has accumulated over the years. Whatever you do, DO NOT USE LACQUER THINNER! (It will dissolve the finish). Wet # 0000 steel wool with the paint thinner or cigarette lighter fluid and give it a good rubbing, going with the grain (careful not to rub off the finish). Do this until it looks nice an clean, then wipe it down with the fluid. If the finish looks good at this point, go to step #3. If the finish is discolored, has minor surface scratches, or irregular or blotched color, I recommend and use "Mar-A-Way". It can be purchased from the distributor in Portland, Hoch & Selby just off Sandy Blvd on 25th Ave. Scratches that go through the finish will not be corrected by using Mar-A-Way.

(3) After you get it clean and smooth, touch up any remaining scratches with a felt tipped staining pen of the correct color. I recommend and use either the "Miller" or "Mohawk" brand felt tip touch-up staining pens, they come in a variety of colors. I've tried the Minwax" brand with disappointing results. Now, if the original finish is intact, go to step #5. Only do step #4 If the finish is worn into the wood.

(4) Now give the treated area several coats of lacquer (I prefer Deft), steel wool it again (no more cigarette lighter fluid) then clean (to remove the dust particles) now a few more coats of lacquer and give it a final steel wool rub down. Clean it  real good and do step #5.

(5)  The finish will now look too glossy (or dull if your just completed step #3). Now here's the real secret of restoring it back to an original looking finish. Rub the entire cabinet with a "Deluxing " compound. You can find such a product under the Mohawk or Behlen brands at most woodworkers suppliers. A good rubbing with these product will give amazing results and well worth the time and "elbow grease". If you can't find a deluxing rub, make your own by using rottenstone wetted with lemon oil.

Closing note, step five should always be done on any newly painted or refinished cabinet for that original finish look. Not doing so will give it that just painted or obvious refinished look.

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Tip #19  old style spaghetti, make your own

When restoring old battery radios (and some early AC sets) of the 20's you'll often need the old style lacquered spaghetti which can be difficult (if not impossible) to find.

When it comes to the old style spaghetti, you can make your own