It should be considered the rule rather than the exception, that all the tubes in an old domestic radio work. It is the passive components around them, which fails. Conversely, even if a tube tests good, then you still have to thoroughly test it in circuit. The triode oscillator in the conversion tube is a famous example, particularly if the receivers has SW bands.
Additionally, this particular triode is very, very frequently completely dead, but just this half of the converter tube. So the triode dies from having heater voltage applied without HT, causing cathode poisoning.
Yet if you only want the receiver to receive FM, you can simply ignore this issue, and keep using the tube. Eventually you will know which tubes tend to be trouble makers, either inherently, or due to their position in the schematic. Low quality tube testers, like those found in your local repair shop back in the day, are largely useless marketing machines, meant to increase revenue for the tube manufacturers. The inductors and high frequency caps rarely fails, except when there is obvious, mechanical damage.
Particularly for the high end receivers from the eighties you will very, very much need this, if you want to have any hope of restoring the factory spec audio quality. The simple decoders found in receivers from the sixties can also be finicky to align without one.
I agree on the wobbulator with you but you need to know how to operate it the right way and it can be done without. They did it for decades i had several and also build a few myself.
Today I rarely use one. However for cavitys I prefere TDR. I use a tubetester mainly for matching tubes used in instruments lile scopes, sweepers, meters or generators. The Ohm meter showed no problems but my Weston tester showed a short in a tube. I replaced it and the problem was solved.
Done a few radios, a few Yaesu transceivers, a few Racals and Murphys, a collins, T and some otjer militairy stuff. Most jobs are restoring or repairing instruments, from multimetes to network analysers, also a lot of calibration gear, and you need more gear for that. I do have an LCR meter Just recently acquired that.
Forgot to mention that. I wont be working on anything from the 80's I don't think. I plan on only working on the old tube radios in the wooden boxes. My other hobby is woodworking so I am hoping to combine the two hobbies. Restoring Bakelite or plastic cabinets is mostly a matter of cleaning and polishing.
I recommend starting with the gentlest possible means and materials and resorting to stronger methods only if necessary. I begin with warm, soapy water, some clean, soft cloths, and a soft toothbrush for the small crannies. Cotton Q-tips and round toothpicks also come in handy for tight spots.
Beware of powerful solvents, especially when working with an unknown modern plastic. Nothing is more disheartening than watching your newfound treasure start to dissolve under your fingertips! For everyday cleaning, I use nothing stronger than Windex or isopropyl alcohol rubbing alcohol. Novus polish is gentle enough to safely polish the most delicate plastic dial covers, yet the 2 grade works on Bakelite, too. Other collectors polish with various substances, such as very fine-grade automotive rubbing compound, power buffing wheels, and so on.
Some collectors wax Bakelite cabinets after polishing, but I've not found that worth the bother, if you've done a good job of polishing.
Be patient and stay with soft cloths and elbow grease. Caution: the shiny surface layer of Bakelite is quite thin; if you polish too hard with harsh abrasives, you'll dig down into the pulpy underlayer of the Bakelite, which nothing will make shiny again. If your cabinet is damaged from sanding or too-harsh polishing, the only remedy is to repaint it. Cracks in Bakelite and plastic cabinets be re-glued with cyanoacrylate "crazy glue" if the break is clean.
Larger defects in a plastic cabinet can be patched with a product called "Plas-T-Pair," available from Antique Electronic Supply. Larger breaks in a Bakelite cabinet may be harder to repair, although I have heard of people patching them with a mixture of ground Bakelite and some sort of glue.
The best learning method is to watch over the shoulder of an experienced repairman. Our Restoration section has many articles on restoring specific radios. These articles contain all sorts of tips and practical advice about repairing electronics and refinishing cabinets.
Books , as mentioned earlier, are another excellent resource. Be sure to check out the Antique Radio Forums website discussions. Browsing these forums will uncover a wealth of information about restoration techniques, and you can also ask forum members for advice about your project. Again, if you're a complete novice in electronics, I recommend practicing on a junky radio before you tear into your treasured antique.
A visit to the local thrift store may provide a suitable tube-powered patient for only a few dollars. It won't be exactly like your "real" radio, but the techniques that you learn will be generally applicable. Practicing on a junker will tell you whether you like this activity, and you can make those inevitable beginner's mistakes on a set that doesn't have great emotional or monetary value.
Phil's Old Radios:. How can I fix my old radio? Hardly a week goes by without somebody sending me a message like this: Help, Phil! If you're in this position, here are some answers to help you get started. Should I fix it myself, or hire someone to do it? How much will it cost to restore my radio? Where can I find someone to fix my radio?
Is there a book that I can read? Are parts still available? What skills do I need? January 30th , pm pschuch. September 15th , pm Rod Clay. August 11th , pm FrankB. July 22nd , pm K5CSU. May 26th , pm FrankB. May 3rd , pm FrankB. April 23rd , pm Rod Clay. March 9th , am Martin. March 8th , am Martin. March 2nd , am johnwater. December 28th , am ve1arn.
December 13th , pm FrankB. Rod Clay. A note about my for sale and reference gallery pages. Both for sale items and my photo reference gallery are shown on their respective pages. When you access these pages the reference gallery right column serves as an informational page for service data if available and other information including photos of the subject item.
0コメント