High Fidelity Tubes

Remember last time that you were tube rolling in the dark? Well this could be the result of it, the keyway completely broke off. Still I wonder how people manage to do this. Specially with a valuable tube like this RCA 5692 extra care should be taken.

Luckily it did not damage the tube itself and it still works, but next time be carefull when you install it. To prevent further damage and restore the original beauty of this tube, I will show you how to restore the keyway using this replacement.

With a needle file remove the last pieces of the original keyway.

Once the base is prepared put the new keyway correctly in place.

Optionally glue it to the base with Mastic Silicone Kit.

Unfortunately there are more tubes arround that have been hurt. Look at this Telefunken EL34 “Wing Plate”, the best ever made. Very rare, expensive but less wanted with a broken keyway

Remove the last part of the original keyway using a small cutter and needle file. Care must be taken because the material of the socket can be very brittle.

Once the base is prepared, we restore the keyway with this replacement.

More soon.

Miniature Pentode for input stages. Representative of the large Amperex line of audio tubes is the EF86/6267 nine-pin miniature pentode. Which is designed for preamplifier and input stages having strigent requirements with regard to hum, noise, and microphones.

It is a direct replacement for the older Z729. It is one of the Amperex “Preferred” types for high-quality audio application. Amperex Electronic Corp., 230 Duffy Ave., Hicksville, L. I., N. Y. (August 1961)

Model 533DM, Dealers who are using this tube tester enthusiastically report that it is the best salesman they ever used. Customer convincing, the 533-DM contains a huge, illuminated nine-inch meter that clearly and accurately shows condition of the tube under test. Dual-scale provides micromho readings for the technician and a multi-color “Good”, “Replace” scale for easy customer interpretation across the counter.

“Attractive Display Model and Most Effective Tube Salesman”

Contains the Hickok Tube Gas Test, and a circuit for accurate forcast of future tube life. Detects more weak tubes. Tests all the latest tubes including television. 9″ chrome meter case, satin finish aluminum panel. Strong , attractive, enameled steel case. 110-130 V.A.C. Price: $199.20 (1953).

Model 700, most accurate tube tester available for precise development laboratory measurement of Mutual Conductance. Provides 4 seperate signal voltages with micromho ranges from 1500 to 60,000. Duplicates results in tube manuals. Places separate voltage on each element of the tube. Voltages can be varied and measured separately in each circuit. Provides means for complete curve study of any particular tube. Designed to never become obsolete. Complete with all leads. Price: $750 (1953).

“Laboratory Model”

Model 7001, Additional Null Reading Device, for use with the Model 700 for obtaining bridge type null readings with accuracy of ½ of 1%. Case matched to the set Price: $162.30 (1953).

Model 7002, Short and Leakage Test Accessory for use with the Model 700 to check for shorts between all elements. Matched to the set. Price: $145.00 (1953).

Model 533AC, a lower cost dealer’s counter model. Attractively designed to set on the counter and increase your tubes sales. Highly accurate Dynamic Mutual Conductance circuits. Encourages customers to bring their tubes in where they can see the actual test. If customers’ tubes check “OK” you have an excellent opportunity to invite him to bring his receiver in for a thorough check of all its circuits. With the 533-AC you will build customer confidence, increase tube sales and promote your complete radio and TV service.

“Dynamic Mutual Conductance in A Smaller Counter Model”

Satin finished aluminum panel. Beautifully styled, blue enameled steel case.

Specifications: Dual-scale meter provides readings in microhoms for the techinician and “Good”, “Replace” scale for easy customer interpretation. Quick, impressive, accurate, and dependable. Detects more weak, ordinarily passable tubes. Contains the Hickok Tube Gas Test, and a circuit for accurate forecast of future tube life. Simple to operate. Contains all necessary tube information on a handy built-in roll chart. Tests tubes under simulated operating conditions. Tests all the latest tubes including television. Large 5″ easy-to-read meter scale and calibrated GM circuit provide increased accuracy in testing today’s newer tubes. Price: $185.80 (1953).