Supreme Model 576 RF Generator
This is one of Supreme's smaller signal generators from the 1940's. It has a chromed chassis just like its big brorher the model 561 and the exact same frequency range.
The combination of the model 576 wth the model 563 audio generator would duplicate a lot of the functionality of the model 561 combination generator, except for features like the continuously variable modulation audio and the FM modulator. The 576 can only be AM modulated with a fixed 400CPS tone.
The combination of the model 576 wth the model 563 audio generator would duplicate a lot of the functionality of the model 561 combination generator, except for features like the continuously variable modulation audio and the FM modulator. The 576 can only be AM modulated with a fixed 400CPS tone.
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It's dirty and needs cleaned, as usual, but overall it's in pretty good condition. The case will also need repainted.
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The face looks good, just a small scratch or two to touch up, and of course there's all the dirt.
This instrument is a fairly early serial number 191. It's circuit varies slightly from the 1945 schematic available online: the line fuse is before the power line filters and the capacitor across the modulation transformer is 0.012mfd instead of 0.02mfd as shown on the schematic. |
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There's three tubes, a 6X5 rectifier, a 76 audio modulator, and hidden behind the black RF coil support is a 6A8 RF oscillator and buffer.
This small generator has an AC line fuse but their top of the line 561 doesn't. You'd think it would be the other way around. |
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The side view shows the 6A8 under the shield for the RF coils.
The chromed chassis is a really nice feature, and the chrome is still in decent condition with just some light pitting. |
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The underside looks original. Most of the resistors measured out of tolerance and I count seven paper and foil capacitors top and bottom that need replaced. Plus the dual 8mfd electrolytic has to go.
The inductor on the left is the power supply choke, and the one on the right is the modulation transformer. |
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The generator came with the original output cable still plugged in. But its shell was bent and now I see the socket is busted too, so the generator must have been dropped on its face or something smacked the connector hard (like most gear I buy online, seems there is always undisclosed damage).
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Inside the shielded multiplier can there are three 910Ω resistors and four 100Ω just like the multiplier in the model 561. The 0.02μF capacitor is in series with the output line and prevents external DC voltages from overheating the multiplier resistors.
Someone has opened, or tried to open, the can because the edge around the back half is all bent up. |
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More to come...
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Page created 5/6/2022
Last edited 5/7/2022
Last edited 5/7/2022
