Randy Rago's Page

"Kent, a privilege to meet you. At this time, I dont need any more parts. The set belongs to a client who MAY want to acquire more original cosmetic parts. I will put him in touch with this group when I return the set to him. Thanks"

"The Masterpiece was released after the Super XII was discontinued. Knowing how Scott reused parts, I'm not surprised at the similarities. With the exception of the Laureate, all the sets from the Philharmonic through WW2 are basically the same…"

"Randy -  I regard the 14 tube Scott Masterpiece as a souped up Super 12. It changed from a single 6J5 tube driver to push-pull pair of 6J5 drivers in the Masterpiece. The final (3rd) version Super 12 receiver also has 6 rather than 4 controls,…"

"one more detail that may be interesting. this unit, No. JJ345, has circuitry that matches the Super VII up to the 3rd IF/AVC/ and 1st audio section. here there is a dual 10UF can that does not appear in the Masterpiece schematic. they have been…"

"David, Although this is my first Scott, I've been in this since '72. the approach i've developed is first, power supply electrolytics, next audio section, then tuner section. this method has proven quick and effective for me. I…"

"In recent years, I have been testing at voltage the old caps I have removed. Using an EICO 950B Comparative Bridge I restored. Most caps leak badly. I replace all the caps in higher voltage circuits before ever using a Variac to apply power, while…"

"Yes Kent is.  Also, co-author of the Scott Collectors Guide, 2nd edition. And the primary force behind this Scott Enthusiasts web site."

"Excuse me, Mr. King, are you Kent A. King, one of the founders of the Scott Historical Society?"

"👍"

"Randy - Dave's suggestion is one he and I have used in the past. I'll check to see if there are socket voltages, but <in general> you should see higher voltages (150-250) on pins 3 (plate) and 4 (screen) for most of the RF/IF and…"

"Thanks, David. Im not a shotgun repairer, i change then test so i dont loose my place. Lack of detailed documentation has not helped. I have read that Scott published troubleshooting docs but seems they're rare. So before i disconnect and light…"

"so, something sucking off voltage after the first 2K section of the B+ voltage divider? Have you replaced all the various original paper/wax/foil caps in the receiver? If so, then You might try detaching each wire off the B+ divider (one at a time)…"

"After some time off, I’m back into the Masterpiece project. Thanks to all who helped before with the grid wiring. Im at a major roadblock with the bias resistor network. Previously, the first value after the 230V showed 6100 ohms way out, the…"

"230v drop across 7560 ohms gets me close to 6 watts across the array. So 10 watters will be good. Nice catch on that noted 25v drop across two different values! Factor in a +/- 20 % tolerance and im fine. Thanks for the input."

"They wattage can be calculated via Ohm's law and the power formula. However, to shortcut those calculations, if you make each a 5W unit, you should be ok. Making the big one (3825) a 10W unit would be prudent. I never noticed the schematic…"

"Nevermind, did the math. 6 watts, using 10 watters"