Amptech Systems & TUBETVSHOP.COM
This is the Restoration Shop, where new life is breathed into classic electronic equipment.
In creating the Amptech Systems service and restoration facilities, my goal was to approximate and improve upon the layout and equipment complement of a well-equipped television and electronics service facility circa mid 1960's. Equipped with instruments which were widely available new and as military surplus at the time, I now have all equipment necessary for servicing a range of sets from mid-1930's (early superheterodyne) radios to 1960's (round CRT) color televisions with optimal ergonomic efficiency. The Main Service Bench is configured in a custom array of Task Centers, incorporating pre-configured instrumentation for frequently-employed task sequences. We have also created a custom-designed 24-MHz IF Alignment station (by modifying an Eico 369 Sweep/Marker generator to provide a Monitor output to a digital frequency meter. This configuration allows us to track the Marker frequency from the master oscillator for the Sound carrier in realtime via a digital readout and generate a crystal-controlled second marker for Video simultaneously. This customized Eico unit allows quick setup for Alignment of B/W sets using non-standard IF center frequencies, approaching the ease of use which our B&K 415 (44 MHz IF Alignment station) provides with Color chassis Alignment setup. Many modern devices such as tv, vcr, hi-fi and guitar amplification systems may also be serviced using these facilities. In 2009, we added some equipment upgrades. We now have more Adaptors for the CK-3000 Test Rig, supporting more chassis configurations. We've added a TIC 1200A Wobbulator for precision RF Alignment.
This is the Schematic Library where classic Service Literature is kept.
This is the Display Room featuring my personal collection of working vintage sets.
Purchasing a Set
We have begun further expansion of our capabilities. Since February, 2009, we have two complete multi-station restoration shops available to meet the needs of our clients. When conventional TV underwent its full transformation to Digital, we at Amptech Systems reaffirmed our dedication to the historic preservation of sets from the early years of the Analog Age by continuing to upgrade our facilities.
Hobbyists and Do-It-Yourself restorers in need of parts or tubes may click here to obtain parts vendor referrals free of charge. We will research your request and reply with a referral to one or more vendors who may have the requested part available for sale, usually within 24-48 hours. Type numbers are typically sufficient for identifying tubes. Manufacturer's part numbers, type numbers and other characteristics are helpful for other parts. Pictures are helpful for identifying unusual parts. We typically keep only frequently-used replacement parts on hand for use in restorations, ordering other parts as needed from a number of outside vendors specializing in New, New-Old-Stock, and/or Used vintage and hard-to-find electronic parts.
This service is provided free of charge, however, donations are appreciated from those who have found our vendor referrals helpful.
Other Related Inquiries
General information regarding vintage electronics is available free of charge. See our Hobbyists' Page first for some topics which we have addressed recently.
HOW WE DO OUR RESTORATIONS
Initial Cleaning and Inspection
All restorations begin with careful study of the service manual for the device. The equipment to be restored is cleaned to allow a thorough and accurate inspection. The chassis is removed from the cabinet, carefully dusted and vacuumed. After the chassis and components are cleaned, all components are inspected to spot obvious signs of component failure. Such indications as cracks, breakage, melting or burning of components are noted for further investigation. Any severely damaged parts are noted for immediate replacement. All tubes (including TV picture tubes) are individually tested using an appropriate tube tester.
Modern Overload Protection
Many vintage sets had inadequate overload-protection provisions. Some had no such protection at all. We add fuses to protect the set's AC line circuit, main B+ supply, and television horizontal deflection circuits. We use special subminiature fuse devices which are easily concealed under the chassis, often using existing terminal lugs as connection points. Wherever possible, we use vacant terminals of tube sockets after consulting engineering data for the specific type of tube as many tubes' unused pins may be used as "tie points" for other components unless otherwise noted in the engineering data. Use of tube socket "vacancies" in this manner also facilitates testing of the fuses without removing the chassis from the cabinet when a blown fuse is suspected. External appearance of the set is not modified unless a client specifically requests a user-accessible line fuse installation. Protective devices are specifically selected to minimize the risk that some future failure of a tube or other component could initiate "chain-reaction" damage affecting other parts for which replacements may be expensive or hard to find.
Electrolytic Capacitor Re-Forming
In the previous steps, electrolytic capacitors were inspected for signs of pressure or blow-out at their safety seals. which are clear indications of previous failure. Capacitors which have already failed were noted for replacement. Those which do not show signs of failure will have their internal aluminum oxide dielectric film re-formed using a controlled electrochemical process. After re-forming is complete, the capacitors are tested for correct performance. Tests include ESR (Equivalent Series Resistance), DC Leakage, and Capacitance/Tolerance. By testing ALL THREE of the key indicators for proper electrolytic capacitor performance, we maintain optimum set operation, maintain original appearance, and eliminate unnecessary replacement of these components. New-manufacture multi-section aluminum electrolytics may be available (from one of our preferred vendors) in some instances where replacement is required. We have also just completed development of an improved process for concealing new electrolytic capacitors inside the existing metal cans in instances where the original capacitors have actually failed, must be replaced, and our vendor does not carry a suitable replacement for the unit(s) to be replaced. This process eliminates re-engineering of under-chassis wiring and avoids blocking access to critical test points which could occur when new electrolytics are installed under the chassis in the conventional manner. Future maintenance is less difficult with our improved method. Rebuilt units will be fitted with a Rebuilt By Amptech Systems label showing the date when the rebuild was performed. Due to the higher chances of a reformed capacitor failing, we cannot warrant them. Restuffed cans are warranted.
Circuit Resistance Check
Service manuals typically contain charts showing normal resistance measurements between individual tube pin connections and the set's "ground" point. Measurements are taken in this step for comparison to the service manual's chart of normal values. Differences of greater than 10%-20% are noted, investigated and corrected.
Electronic Functional Evaluation
RF/IF Response Test
Most sets' service manuals specify a procedure for a general response check of the set's Radio Frequency and Intermediate Frequency circuits. In this step, the results of the test are compared with figures shown in the manual. Incorrect results are investigated and corrected as necessary. Full system alignment is performed if test results indicate a need for it or if the customer requests re-alignment.
This step is normally necessary for pre-1964 sets, but optional for sets in which epoxy-dipped film-dielectric capacitors were supplied by the OEM. By this phase in the procedure, all failed and/or failing components have been replaced; normal operation of all circuits has been restored; and no further work is required. Purely from a standpoint of preventive maintenance, customers may request replacement of components for which there is no immediate need for replacement. We recommend installing epoxy-sealed plastic film capacitors in place of all paper/wax units for preventive purposes. About 15 aluminum electrolytic capacitors are used in the typical vintage television chassis as individual units or combined in multi-section devices. If more than 30% of these have needed replacement to achieve normal operation, replacement of all aluminum electrolytic capacitors may be an appropriate preventive measure. A report of the set's test results will be completed and a summary of the results and recommendations will be furnished (usually via email) to the customer upon completion of each phase of restoration.
We now have the capability of rebuilding multi-section can-type electrolytic capacitors of the "twist-lock" type. We open the can, remove the inner structures, rebuild with new electrolytics, and finally re-seal the can. This is a labor-intensive process performed only on units having at least one section which has failed any of the three tests which we perform on every electrolytic capacitor in the sets we restore and for which no New or New-Old-Stock direct replacement unit is available. We prefer, when available, to use fresh-stock CE Manufacturing capacitors, NOS capacitors from other vendors if there is no current-production CE Manufacturing unit suitable for the application, and rebuilding is our next option for those "don't have and can't get" types. All components to be used in our rebuilds are pre-tested and then re-tested after assembly. Each phase of testing is the same three-step testing which the original capacitors had undergone. The rebuilt capacitor section being post-tested below, rated 40uF with original tolerance of -10%/+20%, is well within tolerance at 47.3uF. Leakage current measured a full 33% below maximum acceptable value at 10% above rated voltage, and ESR measured less than 1 ohm.
Final Adjustments and Burn-In
After all required and recommended procedures have been performed and satisfactory operation of the chassis has been verified, the set is fully reassembled and set up in the shop. Its final adjustments are performed and the set is subjected to a burn-in period. During this phase, I watch several hours of off-air programming and videotaped test patterns on the set to further confirm correct and reliable performance.
The results and recommendations from each step have been submitted to the customer at each phase of the restoration process. A minimum and maximum cost estimate has accompanied each reporting summary. Final cost of restoration is calculated and an invoice is generated for final billing. Due to the complex nature of the systems under test and work being performed, diagnostic charges may apply even if the process is aborted due to preliminary cost estimates' exceeding the maximum approved by the customer. The maximum diagnostic charge will be within +/-10% of the minimum cost estimate specified in the most-recent reporting summary and represents the time and materials involved to this point. Typical diagnostic and reporting charges are $50 to $100. Completed restorations typically bill as the average of the most-recent minimum and maximum cost estimate +/-10%. Typical charges for completed functional restoration are $150-$500. Special procedures such as recapping and cabinet refinishing may result in final charges of $500-$1,000. Return shipping charges also apply unless the set is to be picked up personally at my shop.
Special Note (TV Picture Tubes)
TV Picture Tubes are very hard to find. We do not normally have access to any new ones. We have, however, found providers of rebuild service for most all-glass and some metal-and-glass picture tubes. This service is very expensive, however, and recommended only under special circumstances. A rebuilt picture tube will add at least $300 to final restoration cost. In most cases, the cathode of a weak tube may be electrically re-activated to achieve satisfactory performance for normal light-duty operation of the set for demonstrations. Monthly demonstrations of 1-2 hours duration are recommended and re-activated tubes normally continue to function for several years under these conditions before rebuilding or replacement becomes necessary. Occasionally, a suitable used tube may be obtained for a fraction of the cost of rebuilding the tube. As of 05/20/2018, a used 10BP4 (1940's-vintage round B/W) tube costs about $175. For some 1950's-vintage rectangular B/W tubes, New Old Stock replacements are available on a limited basis from a local warehouse. Picture tubes MUST be intact and under vacuum in order for our rebuilding vendor to successfully complete the rebuilding process. If your set's CRT is broken or otherwise obviously not under vacuum, a rebuildable replacement tube must be obtained.
Special Note (Very Early Color TV)
We typically refer owners of certain very early Color TV models such as: RCA's CT-100 and 21CT55; Westinghouse H840CK15; Motorola 19CT1; and others using CRT types 15GP22, 15HP22, 19VP22, and certain models using type 21AXP22 to colleagues who have serviced multiple examples of these sets. Our shop's equipment is best suited to the Restoration of Color TV models using all-glass CRT types such as 21CYP22. Certain models using metal type 21AXP22 are compatible with our test bench (RCA chassis CTC4 and later, Sylvania 31C606 and 31T304, and other "second generation" 21" Color TV models). Any "roundie" color set of 1957-67 vintage using a 21CYP22, 21FBP22, 21FJP22 or later-1960's models using a rectangular CRT such as 25AP22 is typically has direct "plug-and-play" compatibility with our bench-testing apparatus (Sylvania model CK3000 test rig).
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Last modified: 05/20/18